UDC
NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA
P
GB 50011 500 11−2010
Code for Seismic Design of Buildings
Issued on: May 31, 2010 Jointly Issued Issued by
Implemented Implemen ted on: December 1, 2010
Ministry of of Housing and Urban-Rural Urban-Rural Construction Construction of the People’s People’s Republic of China General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China
NATIONAL NATIONAL STANDARD STANDARD OF PEOPLE’S REPUBLIC OF CHINA
中华人民共和国国家标准 Code for Seismic Design of Buildings
建筑抗震设计规范 GB 50011 2010 Chief Development Department: Ministry of Housing and Urban-Rural Development of the People’s Republic of China Approval Department: Ministry of Housing and Urban-Rural Development of the People’s Republic of China Implementation Date: December 1, 2010
Beijing
2010
NOTICE This code is written in Chinese and English. The Chinese text shall be taken as the ruling one in the event of any inconsistency between the Chinese text and the English text.
2
Announcement of Ministry of Housing and Urban-Rural Development of the People’s Republic of China No. 609
Announcement on Publishing the National Standard “Code for Seismic Design of Buildings” “Code for Seismic Design of Buildings” has been approved as a national standard with a serial number of GB 50011 －2010 and shall be implemented from December 1, 2010. Herein, Articles 1.0.2, 1.0.4, 3.1.1, 3.3.1, 3.3.2, 3.4.1, 3.5.2, 3.7.1, 3.7.4, 3.9.1, 3.9.2, 3.9.4, 3.9.6, 4.1.6, 4.1.8, 4.1.9, 4.2.2, 4.3.2, 4.4.5, 5.1.1, 5.1.3, 5.1.4, 5.1.6, 5.2.5, 5.4.1, 5.4.2, 5.4.3, 6.1.2, 6.3.3, 6.3.7, 6.4.3, 7.1.2, 7.1.5, 7.1.8, 7.2.4, 7.2.6, 7.3.1, 7.3.3, 7.3.5, 7.3.6, 7.3.8, 7.4.1, 7.4.4, 7.5.7, 7.5.8, 8.1.3, 8.3.1, 8.3.6, 8.4.1, 8.5.1, 10.1.3, 10.1.12, 10.1.15, 12.1.5, 12.2.1 and 12.2.9 are compulsory ones and must be enforced strictly. The former standard “Code for Seismic Design of Buildings” GB 50011 －2001 shall be abolished simultaneously. Authorized by the Research Institute of Standard and Norms of the Ministry, this code is published and distributed by China Architecture & Building Press.
Ministry of Housing and Urban-Rural Development of the People’s Republic of China May 31, 2010
Foreword The standard is revised from “Code for Seismic Design of Buildings” GB 50011 －2001 by China Academy of Building Research (CABR) together with other institutions related to design, survey, research and education in according to the requirements of Document Jian Biao [2006] No. 77 — “Notice on Printing and Distributing [Development and Revision Plan of Engineering Construction Standards and Codes in 2006 (Batch 1)]” issued by the former Ministry of Construction (MOC). During the process of revision, the editorial team summarized the relief experiences accumulated in Wenchuan Earthquake in 2008; adjusted the seismic precautionary Intensity; added the compulsory provisions on sites in mountainous areas, framed structure filler seismic wall arrangement, staircase of masonry structure, seismic structure construction; and raised the requirements on fabricated floor framing and steel bar elongation. And the editorial team carried out studies on specific topics and some tests concerned. Experiences and lessons, learned from the damages resulted from the strong earthquakes having occurred in recent years home and abroad (including Wenchuan Earthquake), are summarized, new achievements of earthquake engineering research are involved, the economic condition and construction practices in China are taken into account, comments from the relevant design, survey, research and education institutions as well as seismic administration authorities are widely collected over the country. Through repeated discussion, revision, substantiation and pilot design, this version has been finalized. This newly-revised version consists of 14 chapters and 12 appendixes. Besides remaining the partially-revised provisions in 2008, the main revisions at this edition are as: supplement the provisions in the aseismic measures against Intensity 7 (0.15g) and Intensity 8 (0.30 g), and adjust the design earthquake grouping in accordance with “the China Seismic Ground Motion Parameter Zonation Map”; modify the soil liquefaction discriminating formula; adjust the damping adjustment parameter in Seismic Influence Coefficient Curve, damping ratio and bearing force seismic adjustment coefficient of steel structure, and horizontal shock absorbing coefficient calculation, and supplement the calculation method for horizontal and vertical earthquake action of large-span building; raise the requirements in aseismic design of concrete-framed house, bottom-framed masonry house; propose the seismic Grade of steel structure house, and adjust the provisions in aseismic measures correspondingly; modify the aseismic measures of multi-story masonry house, concrete-seismic-seismic wall house, reinforced masonry house; expend the application scope of houses with seismic isolation, energy dissipation and shock absorption; add the design principles on performance-based seismic design, and the aseismic design provisions of large-span building, subterranean building, framed and trestled plant building, steel shotcrete-concrete frame and structure steel frame-reinforced concrete core-seismic wall. Cancel the contents involved with inner frame brickwork. The provisions printed in bold type are compulsory ones and must be enforced strictly. The Ministry of Housing and Urban-Rural Development is in charge of the administration of this code and the explanation of the compulsory provisions. China Academy of Building Research is responsible for the explanation of specific technical contents. All relevant organizations are kindly requested to sum up and accumulate your experiences in actual practices during the process of implementing this code. The relevant opinions and advice, whenever necessary, can be posted or passed on to the management group of the national standard “Code for Seismic Design of Buildings” of the China Academy of Building Research (Address: No. 30, Beisanhuan Donglu, Beijing, 100013; i
E-mail:
[email protected]). Chief Development Organization: China Academy of Building Research (CABR). Participating Organization: Institute of Engineering Mechanics (IEM) of China Seismology Bureau; China Institute of Building Technology Research; China Institute of Building Standard Design & Research; Beijing Institute of Architectural Design; China Electronics Engineering Design Institute; China Northwest Institute of Building Design and Research; China Northwest Institute of Building Design and Research; China Northeast Instit ute of Building Design and Research; China East Institute of Building Design and Research; China Mid-south Institute of Building Design; Institute of Building Design and Research of Guangdong Province; Shanghai Institute of Architecture Design; Institute of Building Design and Research of Xinjiang Autonomous Region; Institute of Building Design and Research of Yunnan Province; Institute of Building Design and Research of Sichuan Province; Shenzhen Institute of Architecture Design; Beijing Geotechnical Institute, Shanghai Tunnel Engineering and Rail Traffic Design and Research Institute; China Construction (Shenzhen) Design international; Architecture Design Genenal Institute of China Metallurgical Group Corporation; China National Machinery Industry Corporation; China IPPR International Engineering Corporation; Qinghua University; Tongji University; Harbin Building University; Zhejiang University; Chongqing University; Yunnan University; Guangzhou University; Dalian University of Technology; Beijing University of Technology Chief Drafting Staff: Huang Shimin, Wan Yayong (The following is according to the Chinese phonetic alphabetically) Ding Jiemin, Fang Taisheng, Deng Hua, Ye Liaoyuan, Feng Yuan, Lu Xilin, Liu Qiongxiang, Li Liang, Li Hui, Li Lei, Li Xiaojun, Li Yaming, Li Yingmin, Li Guoqiang, Li Linde, Su Jingyu, Xiao Wei, Wu Mingshun, Xin Hongbo, Zhang Ruilong Chen Jiong, Chen Fusheng, Ou Jinping, Yu Yinquan, Yi Fangmin, Luo Kaihai, Zhou Zhenghua, Zhou Bingzhang, Zhou Fulin, Zhou Xiyuan, Ke Changhua, Lou Yu, Jiang Wenwei, Yuan Jinxi, Qian Jihong, Qian Jiaru, Xu Jian, Xu Yongji, Tang Caoming, Rong Baisheng, Cao Wenhong, Fu Shengcong, Zhang Yiping, Ge Xueli, Dong Jincheng, Cheng Caiyuan, Fu Xueyi, Zeng Demin, Dou Nanhua, Cai Yiyan, Xue Yantao, Xue Huili, Dai Guoying Chief Examiners: Xu Peifu, Wu Xuemin, Liu Zhigang (The following is according to the Chinese phonetic alphabetically) Liu Shutun, Li Li, Li Xuelan, Chen Guoyi, Hou Zhongliang, Mo Yong, Gu Baohe, Gao Mengtan, Huang Xiaokun, Cheng Maokun
ii
Contents 1
General Provisions ............................................................................................................... 1
2
Terms and Symbols.............................................................................................................. 2
3
4
5
6
2.1
Terms......................................................................................................................... 2
2.2
Main Symbols ........................................................................................................... 3
Basic Requirements of Seismic Design ............................................................................... 6 3.1
Classifications of Seismic Precautionary and Corresponding Criterion ................... 6
3.2
Seismic Influence ...................................................................................................... 6
3.3
Site and Subsoil ......................................................................................................... 6
3.4
Regularity of building configuration and component arrangment .. .......................... 7
3.5
Structural System .................................................................................................... 10
3.6
Structure Analysis.................................................................................................... 11
3.7
Nonstructural Components... ................................................................................... 12
3.8
Seismical Isolation and Energy-dissipation Design ................................................ 12
3.9
Materials and Construction ..................................................................................... 12
3.10
Performance-Based Seismic Design...................................................................... 14
3.11
Earthquake Motion Observation System of buildings... ........................................ 15
Site, Subsoil and Foundation ............................................................................................. 16 4.1
Site........................................................................................................................... 16
4.2
Natural Subsoil and Foundations ............................................................................ 19
4.3
Liquefaction and Soft Subsoil ................................................................................. 20
4.4
Pile Foundation ....................................................................................................... 24
Seismic Action and Seismic Checking for Structures... ..................................................... 27 5.1
General Requirements ............................................................................................. 27
5.2
Calculation of Horizontal Seismic Action ............................................................... 31
5.3
Calculation of Vertical Seismic Action.................................................................... 36
5.4
Seismic Checking for Cross Section of Structural Components ............................. 37
5.5
Seismic Check for Deformation .............................................................................. 38
Multi-storey and Tall Reinforcement Concrete Buildings ................................................. 42 6.1
General Requirements ............................................................................................. 42
7
8
9
10
11
12
6.2
Essentials in Calculation ......................................................................................... 47
6.3
Details of Seismic Design for Framed Structures ................................................... 52
6.4
Details of Seismic Design for the Seismic wall ...................................................... 58
6.5
Details of Seismic Design for Frame-seismic wall ................................................. 62
6.6
Seismic Design Requirements for Slab-column-seismic wall................................. 62
6.7
Seismic Design Requirements for Tube Structures ................................................. 64
Multi-storey Masonry Buildings and Multi-storey Masonry Buildings with Bottom-frame65 7.1
General Requirements .............................................................................................65
7.2
Essentials in Calculation .........................................................................................70
7.3
Details of Seismic Design for Multi-storey Clay Masonry Buildings.....................75
7.4
Details of Seismic Design for Multi-storey Small-block Buildings........................ 80
7.5
Details of Seismic Design for Multi-storeys Buildings with Bottom-frame ........... 82
Multi-storey and Tall Steel Structural Buildings................................................................86 8.1
General Requirements .............................................................................................86
8.2
Essentials in Calculation .........................................................................................89
8.3
Details of Seismic Design for Steel Framed Structures...........................................95
8.4
Details of Seismic Design for Steel Frame-concentrically-braced Structures......... 98
8.5
Details of Seismic Design for Steel Frame-eccentrically-braced Structures...........99
Single-story Factory Buildings ........................................................................................101 9.1
Single-story Factory Buildings with R.C. Columns..............................................101
9.2
Single-story Steel Factory Buildings..................................................................... 112
9.3
Single-story Factory Buildings with Brick Columns ............................................ 118
Large-span Buildings .....................................................................................................122 10.1
Single-story Spacious Buildings .........................................................................122
10.2
Large-span Roof Buildings..................................................................................125
Earth, Wood and Stone Houses ......................................................................................129 11.1
General ................................................................................................................129
11.2
Unfired Earth Houses ..........................................................................................130
11.3
Wood Houses .......................................................................................................131
11.4
Stone Houses .......................................................................................................133
Seismically-isolated and Energy-Dissipated Buildings .................................................134 2
13
14
12.1
General ................................................................................................................134
12.2
Essentials in Design of Seismically-isolated Buildings ......................................135
12.3
Essentials in Design of Energy-dissipated Buildings ..........................................141
Nonstructural Components ............................................................................................146 13.1
General ................................................................................................................146
13.2
Essentials in Calculation .....................................................................................146
13.3
Essential Measures for Architectural Members................................................... 148
13.4
Essential Measures for Supports of Mechanical and Electrical Components .....151
Subterranean Buildings ..................................................................................................152 14.1
General ................................................................................................................152
14.2
Essentials in Calculation .....................................................................................153
14.3
Details and Anti-Liquefaction Measures .............................................................154
Appendix A
The Earthquake Intensity, Basic Accelerations of Ground Motion and Design
Earthquake Groups of Main Cities in China..........................................................................156 Appendix B
Requirements for Seismic Design of High Strength Concrete Structures ......175
Appendix C
Seismic Design Requirements for Pre-stressed Concrete Structures.............. 176
Appendix D
Seismic Design for the Core Zone of Column-beam Joint of the Frame Structures
...............................................................................................................................................178 Appendix E
Seismic Design for the Transition-storeys ...................................................... 182
Appendix F
Seismic Design for R.C. Block Buildings.......................................................184
Appendix G
Seismic Design for Composite Steel Brace and Concrete Frame Structures and
Composite Steel Frame and Concrete Core Tube Structures .................................................192 Appendix H Appendix J Appendix K Appendix L
Seismic Design for Multi-storey Factory Buildings....................................... 195 Adjustment on Seismic Effects for the Transversal Bent of Single-storey Factory 202 Seismic Check for Single-storey Factory in Longitudinal Direction .............206 Simplified Calculation, General and Details for Seismically-isolated Masonry
Structures ...............................................................................................................................213 Appendix M
Objectives and Procedures of Performance-based Seismic Design............... 218
Explanation of Wording in This Code....................................................................................225 List of Quoted Standards........................................................................................................226
3
1 1.0.1
General Provisions
This code is formulated for the purpose of carrying out the policies of giving priority to the
prevention of earthquake disasters, as well as laws on building engineering and earthquake prevention and relief. So that, when the buildings are made earthquake-precautionary, the damages and loss to buildings, people and economy will be mitigated. The basic seismic precautionary objectives of buildings whose aseismic designs comply with the requirements of this code are as follows: when the place is subject to frequent earthquake influence whose Intensity is lower than the local precautionary Intensity, the buildings can continune to serve free from demage or without repair required; when the place is subjected to local precautionary Intensity earthquake influence, the buildings with possible damge can continune to serve with common repair; when the place is subjected to rare earthquake influence which Intensity is higher than the local precautionary Intensity, the buildings have no collapse or severedamage that would endanger human lives. The building with special requirements in functions and other aspects, when the performance-based seismic design applies, shall have more specific or higher seismic protection target. 1.0.2
Every building, which is situated on zones of precautionary Intensity 6 or above, must be
designed with seismic design. 1.0.3
This code is applicable to seismic design, shock isolation and absorption of buildings situated
on the zone of precautionary Intensity 6, 7, 8 and 9. When buildings are situated on zone where the precautionary Intensity is greater than 9, and/or industry buildings with specific professional requirements, the corresponding design of these buildings shall meet special provisions. Note: For the purposes of this code, “precautionary Intensity 6, 7, 8 and 9” hereinafter refer to “Intensity 6, 7, 8 and 9”.
1.0.4
Precautionary Intensity of a region must be determined by documents (or drawings)
approved and issued by the government. 1.0.5
Generally, the local precautionary Intensity may be adopted the seismic basic Intensity as
provided in “the China Seismic Ground Motion Parameter Zonation Map” (or the Intensity values corresponding to the design basic seismic acceleration in this code). 1.0.6
Not only the requirements on seismic design of buildings stipulated in this code, but also those
in the current relevant current standards of the nation shall be complied with.
1
2
Terms and Symbols 2.1
2.1.1
Terms
Seismic Precautionary Intensity
The seismic Intensity approved by State authority, which is used as the basis for the seismic precaution of buildings in a certain region. Generally, the seismic Intensity with the frequency over 10% in 50 years is adopted. 2.1.2
Seismic Precautionary Criterion
The rule for judging the seismic precautionary requirements, which dependent on the seismic precautionary Intensity and importance of the building’s using functions. 2.1.3
Seismic ground motion parameter zonation map
The map in which the whole county is divided into regions with different seismic protection requirements according to the ground motion parameter (earthquake action degree indicated by acceleration). 2.1.4
Earthquake Action
The structural dynamic action caused by earthquake, that including horizontal seismic action and vertical seismic action. 2.1.5
Design Parameters of Ground Motion
The seismic acceleration time-historey curve (speed and displacement), the response spectrum of acceleration, and the peak value acceleration using in seismic design. 2.1.6
Design Basic Acceleration of Ground Motion
The design value of seismic acceleration, that exceeding probability is 10% during the 50-years reference period. 2.1.7
Design Characteristic Period of Ground Motion
The period value corresponding to the starting point of reduced section of seismic influence coefficient curve, which describes the earthquake magnitude, the distance of epicenter and the site classes etc.. 2.1.8 Site
An area of a building group, usually it has similar characteristic in response spectrum. Its scope is an area approximately equivalent to a factory area, a living quarter, a village or a plain area not less than 1.0km2. 2.1.9
Seismic Concept Design of Buildings
The process of making the general arrangement for the architectures and structures and of determining details, that based on the design fundament principles and the ideas obtained from past experiences in earthquake disaster prevention and the constructional project. 2.1.10
Seismic Measures 2
The seismic design contents except seismic action calculation and component resistance calculation, and details of seismic design included. 2.1.11
Details of Seismic Design
All of detailing requirements, which are determined according to seismic concept design of buildings and that no calculation is necessary. 2.2 2.2.1
Main Symbols
Actions and effects
F Ek , F Evk —— Standard value of total horizontal and vertical earthquake (seismic) action of structure respectively; GE, Geq —— Standard value of gravity load of structure (or component) and the total equivalent gravity load of a structure in earthquake respectively; ωk —— Standard value of wind load; S E —— Seismic effect (bending moment, axial force, shear, stress and deformation); S —— Base combination of seismic effect and other load effects; S k —— Effect corresponding to standard value of action or load; M —— Bending moment; N —— Axial force; V —— Shear force; p —— Compression on bottom of foundation; u —— Lateral displacement; θ —— Rotation of storey draft. 2.2.2
Material Properties and Resistance K —— Rigidity of structure (or component); R —— Bearing capacity of structural component;
f , f k , f E —— Design value, standard value and seismic design value of various material strengths (including bearing capacity of subsoil) respectively; [θ ]—— Allowable rotation angle of storey draft. 2.2.3
Geometric Parameters A —— Cross-sectional area of structural component; A —— Cross-sectional area of reinforcement; s
3
B —— Total width of structure; H —— Total height of structure, or column height; L —— Total length of structure (or structural unit); a —— Distance; as, a's —— Minimal distance from the point for resultant of force of all longitudinal reinforcement in tension and compression respectively to extreme fiber of section; b —— Width of cross section of component; d —— Depth or thickness of soil, or diameter of reinforcement; h —— Height of cross section of component; l —— Length or span of component; t —— Thickness of seismic structural-seismic wall or slab. 2.2.4
Coefficients of Calculation a —— Horizontal seismic influence coefficient; amax —— Maximum value of horizontal seismic influence coefficient;
avmax —— Maximum value of vertical seismic influence coefficient; γG, γE, γW —— Partial factor of action; γRE —— Seismic adjusting factor for bearing capacity of component; ζ —— Calculation factor; η —— Enhancement coefficient or adjusting factor of seismic effect (inner force or deformation); λ —— Slenderness ratio of component, or proportional factor; ξ y —— Yield strength coefficient of structure (or component); ρ —— Reinforcement ratio, or ratio; ø—— Stability factor of compressive component; —— Combination value coefficient, or affect factor. 2.2.5 Others
T —— Natural period of structure; N —— Penetration blows; I l E —— Liquefaction index of subsoil under earthquake; X ji —— Mode coordinate of displacement (relative horizontal displacement of mass i of mode j in the x direction); 4
Yji —— Mode coordinate of displacement (relative horizontal displacement of mass i of mode j in the y direction); n —— Total number, such as number of storeys, masses, reinforcement bars, spans etc.; υse —— Equivalent shear-wave velocity of soil (layer); Ф ji —— Mode coordinate of rotation (relative rotation of mass i of mode j around the axial direction).
5
3 3.1 3.1.1
Basic Requirements of Seismic Design
Classifications of Seismic Precautionary and Corresponding Criterion
Every building shall be assigned to a Precautionary Category and precautionary criterion
in accordance with the current national standard “Standard for Classification of Seismic Protection of Building Constructions” GB 50223. 3.1.2
For Category B, C and D building with the seismic precautionary Intensity 6, earthquake
action calculation may be neglected excepts those specially specified in this code. 3.2 3.2.1
Seismic Influence
The seismic influence on the building situated region shall be described by using the Design
Basic Acceleration of Ground-motion and the Design Characteristic Period of Ground-motion. 3.2.2
The corresponding relationship between the Precautionary Intensity and the Design Basic
Acceleration of Ground-motion is shown in Table 3.2.2. Where the Design Basic Acceleration of Ground-motion is 0.15 g and 0.30 g , unless some particular regulations are specified in this code, the seismic design of buildings shall be adopted that of Precautionary Intensity 7 and 8 respectively. Table 3.2.2
Correspondence Between the Intensity and Design Basic Acceleration of Ground-motion
Precautionary Intensity
6
7
8
9
Design Basic Acceleration of Ground-motion
0.05 g
0.10 (0.15) g
0.20 (0.30) g
0.40 g
Note: g is the gravity acceleration.
3.2.3
The Design Characteristic Period of Ground-motion (Seismic Influence) shall be determined
according to the design earthquake grouping and Site-category of the location of buildings. The design earthquake in this code is divided into 3 groups, and the Characteristic Periods for them shall be adopted according to the relevant provisions in Chapter 5 of this code. 3.2.4
The values of Precautionary Intensity, Design Basic Acceleration of Ground-motion and
design earthquake groups for main cities and towns (at county level or higher level) are indicated in Appendix A of this code. 3.3 3.3.1
Site and Subsoil
When selecting a construction site, a comprehensive assessment has to be taken to
identify the site as favorable plat, unfavorable plat, common plat or hazardous plat to seismic precaution, according to engineering requirements, seismicity of the region, and the geotechnical and seismic geological data of the site. Unfavorable plats shall be avoided except appropriate and effective seismic measures have been taken place. On the hazardous plats, the buildings assigned to Precautionary Category A or/and B must not be constructed and the buildings assigned to Precautionary Category C shall not be constructed. 3.3.2
When the construction site is identified to Site-category I, the seismic design details (or
details) are permitted taken as follows: for buildings assigned to Precautionary Category A or B, the seismic design details could be taken as that based on the local zoning Intensity. For building 6
assigned to Precautionary Category C, the seismic design details could be taken as that based on the Intensity of one Grade lower then local zoning Intensity, but for those in regions of local zoning Intensity 6, the detailed shall be always taken as that based on the local zoning Intensity.
When the Design Basic Acceleration of Ground-motion is 0.15 g or 0.30 g , and the construction
3.3.3
site is assigned to Site-category III or IV, unless some particular regulations are specified in this code, the seismic design details should be taken as that for Precautionary Intensity 8 (0.20 g ) and 9 (0.40 g ) respectively. Design requirement of subsoil and foundation shall be as follows:
3.3.4 1
Foundation of a same structural unit should not be posited on the subsoil with entirely
different features; 2
Foundation of a same structural unit should not be posited separately on natural subsoil and
piles. When foundations with different type or significantly different buried depth, the corresponding measures shall be taken on the related positions of foundation and topside structure according to the differential settlement of two parts of subsoil in earthquake; 3
For subsoil layer consisted of soft clay, liquefied soil, back-filled fresh soil, or extremely
non-uniform soil, the non-uniform settlement or other harmful impact induced by earthquake action shall be evaluated in design and corresponding measures shall be taken. The construction site and the design of building foundations in mountainous regions shall meet
3.3.5
the requirements as follows: 1
The reconnaissance for the building site in mountainous area shall be arranged with slope
stability assessment and control scheme; Aseismic slope seismic wall shall be set up according to local geological and topographic conditions and usage of buildings in combination of the local specific conditions. 2
The slope design shall meet the requirements the current national standard “Technical Code
for Building Slope Engineering” GB 50330; and the relevant friction angle shall be corrected according to the defense Intensity in stability checking calculation. 3
The seismic stability design shall be conducted for the building foundation nearby side slope.
A large enough distance from the building foundation to the outer edge of earth slope or highly weathering rock slope shall be retained in accordance with the seismic zoning Intensity of the site, and corresponding measures shall be taken place to avoid from earthquake failures of subsoil and foundation of buildings as well. 3.4 3.4.1
Regularity of Building Configuration and Component Arrangment
The building design shall specify the building configuration regularity according to the
requirements of conceptual aseismic design. Some measures stipulated in this code shall be taken for buildings with irregular configuration. A special procedure of peer review and evaluation shall be followed up and particularly reinforced measures shall be employed for buildings with particular irregular configuration. The seriously irregular building design shall not be permitted. Note: The building configuration is referred to the change condition of architectural plane form, and vertical section and profile.
7
The building design shall value the influence of the regularity of plane, vertical plane and
3.4.2
vertical profile on the seismic performance and economical rationality. The regular configuration of building should be adopted in priority. The plan arrangement of architecture and lateral-force-resisting components should be regular and symmetrical, the lateral rigidity of structure should be changed equably, and the cross-sectional dimensions and its material strength of vertical lateral-force-resisting components should be reduced along whole s tructure from lower part to upper part gradually, to avoid sudden change in rigidity and bearing capacity of lateral-force-resisting system of the structure. The aseismic design of the irregular building shall meet the relevant provisions of Article 3.4.4 in this code. The plane and vertical irregularity of the building configuration and its component layout shall
3.4.3
be divided according to the following requirements: 1
The concrete house, steel structure house and steel -concrete structured house, having the
plane or vertical irregularly types listed in Table 3.4.3-1 and Table 3.4.3-2, shall be regarded as irregular buildings. Table 3.4.3-1
Plan Structural Irregularities
Type of irregularity
Definitions Maximum storey displacement (storey drift), computed including accidental torsion, at one end of structure
Torsion irregularity
transverse to an axis is more than 1.2 times the average of the storey displacement (or storey drift) at two ends of the structure respectively
Re-entrant corners irregularity
Both projections of the structure beyond a re-entrant corner greater than 30% of the plan dimension of the structure in the given direction Diaphragms with abrupt discontinuities or variations in rigidity, including those having cutout or open
Diaphragm discontinuity
areas greater than 30% of the gross enclosed diaphragm area, or effective width less than 50% of total width of diaphragm, or more distinct from one floor slab to other at same storey
Table 3.4.3-2
Vertical Structural Irregularities
Type of irregularity
Definitions and reference index The lateral rigidity is less than 70% of that in the storey or less than 80% of the average rigidity of the three
Rigidity irregularity
storeys above; the horizontal dimension of local take-in more by 25% than that of next storey lower, except top storey of building or buildings with smaller projecting roof
Discontinuity in vertical The internal forces of vertical lateral-force-resisting components (columns, seismic wall and braces) transfer to anti-lateral-force lower those components by using the horizontal transmission component (girders or trusses) components Discontinuity in capacity
2
The inter-storey capacity is less than 80% that of next storey above
The division of plane vertical irregularity of masonry house, single-storey industrial factory
building, single-storey open house, large-spanned building and subterranean building shall meet the requirements of the related chapters in this code. 3
If the buildings, having multiple irregularity or a irregularity in excess of specified reference
index, shall be regarded as especially irregular building. 3.4.4
For the irregular structure, the analysis of horizontal seismic action and internal force
adjustment of structure shall comply with the following requirements, and the effective seismic design details of weak point shall be taken: 8
1
For plan irregular and vertical regular structure, the three-dimensional computed model shall
be adopted, and comply with following requirements: 1)
For structure having torsion irregularity, torsion effects shall be considered, and the maximum storey displacement or storey drift at one end of structure transverse to an axis should not be more than 1.5 times the average of the storey displacement or storey drift at two ends of structure respectively. When the maximal storey drift is far less than the specified limit, it may be loosened properly;
2)
In case of the unevenness irregularity or partial floor-slab discontinuity, the computational model, conforming to the actual rigidity change of the floor level, shall be adopted; if there is high irregularity, the influence of local deformation of floor-slab shall be considered.
3)
In case of unsymmetrical plane and unevenness irregularity or partial discontinuity, local internal force enhancement coefficient shall be adopted for the part with large torsion according to actual situation, as well as the torsional displacement ratio shall be calculated.
2
For vertical irregular and plan regular structure, the three-dimensional computed model shall
be adopted, the seismic shear forces of weak storeys shall be increased by factor 1.15, the elasto plastic deformation analysis shall be made as required by this code, and comply with following requirements: 1)
Vertical lateral-force-resisting component having discontinuity, its seismic internal force shall be increased by enhancement factors 1.25~2.0 to transfer on the horizontal transmission components, according to Intensity, type of horizontal transmission components, stress condition and geometric dimension;
2)
In case of lateral rigidity irregularity, the lateral rigidity ratio of adjacent storeys, according to the structure type hereof, meet the requirements of the related chapters in this code;
3)
Storey capacity having abrupt discontinuity, the shear capacity of week storey shall not be less than 65% that of next storey above.
3
The structure having plan and vertical irregularities shall be arranged with the measures not
lower than ones in items 1 and 2 of this Article. For especially irregular buildings, by special study, more efficient strengthening measure shall be adopted, or the corresponding seismic performance design is conducted for weak part. 3.4.5
For building with complex configuration, and irregular plane and vertical section, the aseismic
joints shall be determined according to the comparative analysis on the factors like degree of irregularity, subsoil/foundation, and technical economy, and the aseismic joint arrangement shall meet the requirements: 1
If the aseismic joint is not arranged, practical computational model shall be adopted, to
deteminate the easy-damage parts due to stress concentration, deformation concentration or Earthquake twisting effect, and the corresponding strengthening measures shall be adopted. 2
Where seismic joints are arranged on proper positionm, multiple regular bilateral force
resistance units should be formed. The width of aseismic joint shall be enough large which determined 9
in according with seismic precautionary Intensity, the structural material, the structural system, the height, its difference of structural unites and possible aseismic torsion effect; and the two structural unites divided by aseismic joint shall be separated completely. 3
When the expansion joints or settlement joints have be installed, their width shall meet the
requirements for aseismic joints. 3.5 3.5.1
Structural System
The seismic structural system of a building shall be determined through comprehensive
analysis for technical and economic conditions considering following factors: precautionary categories, precautionary Intensity, building height, site conditions, subsoil, structural material and construction. 3.5.2
Structural system shall meet the following requirements:
1
A clear computed model and reasonable transition ways for seismic action.
2
An ability to avoid loss of either seismic capacity or gravity bearing capacity of whole
structure, that is due to damages of some structural portions or components. 3
A necessary aseismic capacity, adequate deformation and energy dissipation ability.
4
Some measures to enhance the earthquake resistance capacity for possible weak points.
3.5.3
Seismic structural system should also meet the following requirements:
1
It should be installed with seismic multiple-defense lines.
2
It should be provided with reasonable distribution of rigidity and bearing capacity, to avoid
existed weak point due to local weakening or abrupt changes so that the great concentrate of stress or deformation may be produced at weak points. 3 3.5.4 1
The dynamic characteristics of the structure in two main-axis direction should be similar. The structural components shall meet following requirements: The masonry components shall be installed the reinforced concrete ring-beams, tie-columns
and core-columns in accordance with relevant provisions, or shall be adopted restraining masonry or reinforced masonry. 2
The concrete components shall be selected reasonable dimensions and installed longitudinal
bars and hoops, to avoid the shear failure occur before flexural failure, the concrete crush occur before reinforcements yielded, and the anchorage and cohesion failure of reinforcements occur before the reinforcement is damaged. 3
In prestressed concrete components, sufficient non-prestressed steel bars shall be arranged.
4
The steel components shall be controlled with reasonable dimensions to avoid the local
instability or whole instability of components. 5
The cast-in-situ RC (reinforced concrete) slab is encouraged to apply for floor and roof of
multi-storey and high rise buildings. While applying the prefabricated RC slab or roof, measures for the roof system and structure and details shall be taken to ensure the integration of connection between RC slabs. 10
3.5.5 1
The connections of seismic structures shall meet the following requirements: The failure of connected nodes of components shall not occur before that of components it
connects. 2
Anchorage failure of embedded parts shall not occur before that of components it connects.
3
The connections of prefabricated structures shall ensure the integrality of the structure.
4
Prestressed reinforcements of prestressed concrete components should be anchored beyond
the exterior face of the core of joint. 3.5.6
The seismic brace system of single-storey fabricated factory shall ensure the stability of whole
structure during an earthquake. 3.6 3.6.1
Structure Analysis
The analysis for internal force and deformation of building structures on Frequent Earthquake
level shall be carried out, unless otherwise provision is issued in this code. In this analysis, it may be assumed that the structure and its components are working at elastic state, so that the internal force and deformation may be calculated with the linear static/dynamic analyzing method. 3.6.2
For structures having irregularity and exited weak points that may result in serious seismic
damage, the elasto-plastic deformation analysis under Rare Earthquake shall be carried out according to relevant provisions of this code. In this analysis, the elasto-plastic static analyzing method or elasto plastic time history analyzing method may be adopted depending on the structural characteristics. Where the specific provisions are specified in this code, the simplified methods analyzing elasto plastic deformations of the structures may be adopted, either. 3.6.3
When the gravity additional bending moment due to seismic storey drift is greater than 10% of
original bending moment, the secondary effect of the gravity shall be taken into consideration. Note: The gravity additional bending moment is the product of the total gravity load at and above this storey by the mean storey drift; the original bending moment is the product of the seismic storey shear by the storey height of the building.
3.6.4
In seismic analysis, the floor and roof s hall be assumed as the rigid, semi-rigid or local flexible
and flexible diaphragm depending on deformation in slab plan and plan form, then the interaction behavior between lateral-force-resisting components may be determined by using above assumption, and then, the seismic internal forces of these components may be obtained. 3.6.5
The structure having rigid diaphragms and nearly symmetric distribution of masses and
rigidity, as well as the structure with specific provisions of this code, could apply the two-dimensional model to carry out the seismic analysis. All other structures shall adopt three-dimensional models to carry out the seismic analysis. 3.6.6 1
The seismic analyses of structures by computers shall meet the following requirements: The determination of computing model, necessary simplified calculation and technique for a
structure shall comply with the actual performance of this structure, and the effects of step components in the stair shaft shall be involved in computing. 2
The technical conditions of computer programmer shall comply with relevant provisions in 11
this code, and the design standards and its contents of special technique shall also be clarified. 3
The analysis for internal force and deformation of complicate structures under Frequently
Earthquake shall be adopted at least two different mechanic models, and the comparison shall be made for the calculation results of these models. 4
The rationality and validity of all the calculation results from the computer programmer shall
be judged and affirmed, and after then it is permitted to use in the project design. 3.7 3.7.1
Nonstructural Components
Nonstructural components of buildings including architectural, mechanical and electrical
components permanently attached to structures, itself and connection with the main structure body, shall be equipped with seismic design. 3.7.2
The seismic design of nonstructural components shall be carried out by those designers, which
are relevant professionals respectively. 3.7.3
Non-structural components attached to floor and roof, as well as the non-bearing seismic wall
of the stair shaft, shall be reliably connected or anchored to relevant structural components so that human injury or damage of important equipment induced by their collapse can be avoided. 3.7.4
For the arrangement of exterior nonstructural walls and partition wall of frame structures,
their unfavorable effects on seismic performance of structure shall be considered; irrational arrangement of these seismic wall that would cause damage to main structure shall be avoided. 3.7.5
Curtain wall and veneers shall be firmly adhered to main structure, so that human injury due t o
their falling can be avoided. 3.7.6
The supports and connections of the mechanical and electrical components permanently
attached to structures shall meet the functional requirements under earthquake, and shall avoid any damage to relevant portions of structures. 3.8 3.8.1
Seismical Isolation and Energy-dissipation Design
The seismically-isolated and energy-dissipated structures shall mainly be applied to buildings
which have higher or special requirements in Seismic safety and use function. 3.8.2
The seismically-isolated and energy-dissipating structures under the Frequently, Precautionary
and Rare Earthquake influence shall meet the requirements higher than that in Article 1.0.1 of this code. 3.9 3.9.1
Materials and Construction
Special requirements on materials and quality of construction for seismic structures shall
be clearly stated in design documents. 3.9.2 1
Structural material property shall meet the minimum requirements as follows: Material strength of masonry structure shall meet the following requirements: 12
1)
The strength Grades of fired common bricks and perforated bricks shall not be less than MU10, and the strength Grades of mortar for such bricks shall not be less than M5;
2)
The strength Grades of small-sized concrete hollow blocks shall not be less than MU7.5, and the strength Grades of mortar for such blocks shall not be less than M7.5.
2
Material property of concrete structure shall meet the following requirements: 1)
The strength Grades of concrete for framed beams, framed columns as well as frame-supported beams and columns, joint-core of structure assigned to seismic Grade 1, shall not be less than C30; the strength Grades of concrete for ring- beams, tie-columns, core-columns and other components shall not be less than C20;
2)
For the longitudinal reinforcements of framed structures and diagonal bracing assigned to seismic Grade 1, 2 and 3, the ratio of the actual ultimate tensile strength to actual tensile yield strength shall not be less than 1.25, the ratio of actual tensile yield strength to characteristic strength of the reinforcement shall not be greater than 1.3, and the actual elongation rate shall not be less than 9% under the maximum tensile stress.
3
Material property of steel structures shall meet the following requirements: 1)
The ratio of actual tensile yield strength to actual ultimate tensile strength shall not greater than 0.85;
3.9.3 1
2)
It shall have obvious yield steps, and the elongation rate shall be greater than 20%;
3)
It shall have good weld-ability and quality shock tenacity.
Structural material property should also meet following requirements: The non-prestressed reinforcements having better elongation, weld-ability and tenacity should
be given priority selective using. The longitudinal non-prestressed reinforcements should be selected the hot-rolling bars HRB400 (not lower than) and HRB335 behaving seismic property, the hoop bars should be selected HRB335 and HRB300 both behaving seismic property too. Note: The inspection method of reinforcements shall comply with the requirement of current national standard “Code for Acceptance of Constructional Quality of Concrete Structures” GB 50204.
2
The strength Grade of concrete for concert structures, like seismic wall, should not exceed
C60; other components, it should not exceed C60 at Intensity 9 and C70 at Intensity 8. 3
The steel type of steel structures should be selected the Q235 Grade B, C, D of carbon
structural steel or Q345 Grade B, C, D, E of low alloy and high strength structural steel; when there is reliable condition, other type and Grade structural steel may also be selected. 3.9.4
In construction of concrete structures, if the main longitudinal reinforcements in original
design have to be replaced by those with higher strength Grade, the following principles shall be taken. The conversion shall be made according to equal tensile capacity design values of such reinforcements, and shall also comply with minimum rate of reinforcement. 3.9.5
For steel structures adopting welded connections, if the thickness of steel plate is not less than 13
40mm and tension along direction of thick, then contraction rate along direction of thick under tension test shall not be lower than allowing values of Grade Z15 specified in the current national standard “Thickness Direction Property of Steel Plate” GB 5313. 3.9.6
In construction of tie-columns and core-columns of masonry structures, and the brick
shear-seismic wall of masonry houses with RC bottom-frame, the masonry wall shall be laid out prior to casting tie-columns and core-columns. 3.9.7
For horizontal construction joint of concrete wall body and frame column, the measures shall
be adopted to strengthen concrete bonding property. For the connection of seismic Grade I wall and transition storey slab to ground concrete wall, the shear bearing capacity of horizontal construction joint section shall be calculated. 3.10 3.10.1
Performance-Based Seismic Design
When performance-based seismic design is conducted for a building structure, the technical
and economic feasibility comprehensive analysis and argumentation on the seismic performance target shall be conducted on the base of the following factors: seismic protection type, defense Intensity, site condition, structure type and irregularity, requirements on use functions of building and ancillary facilities, investment size, post-disaster loss and reconstruction easiness. 3.10.2
According to the actual requirement and possibility, the performance-based seismic design of
building structure shall have pertinency respectively on whole structure, partial part or key part, critical, important and secondary component of the structure, building unit and lug support for mechanical and electrical equipment. 3.10.3
The performance-based seismic design of the building structure shall meet the following
requirements: 1
The seismic motion level is selected. For the structures with the design life of 50 years, the
earthquake action of frequent Earthquake, rare earthquake and precautionary earthquake may be chosen. The acceleration of the precautionary earthquake shall be design basic seismic acceleration listed in Table 3.2.2, and the maximum seismic influence coefficient of the precautionary earthquake may respectively be 0.12, 0.23, 0.34, 0.45, 0.68 and 0.90 for Intensity 6, Intensity 7 (0.10 g ), Intensity 7 (0.15 g ), Intensity 8 (0.20 g ), Intensity 8 (0.30 g ) and Intensity 9. For the structure with the design life of over 50 years, the earthquake action shall be properly adjusted through special study in consideration of the actual requirement and possibility. For the structures within 10km on both sides of shock fracture, the ground motion parameter shall be considered in near-field influence; for those within 5km on both sides of shock fracture, the ground motion parameter should be multiplied by enhancement coefficient 1.5, and the ground motion parameter of the structures outside of 5km should be multiplied by the enhancement coefficient of over 1.25. 2
The selected performance objectives, corresponding to expected damaged condition or
functions of use, shall not be lower than the requirements of basic defense objective specified in Article 1.0.1 of this code. 3
The performance design index is selected. In the design, the specific index to improve the
seismic bearing capacity and deformability of the structure or its vital parts respectively, or to improve the seismic bearing force and deformability simultaneously, shall be selected; the uncertainty of acti on value selection of earthquake with different level, and the clearance shall be considered. In the design, 14
the requirements in the horizontal and vertical component bearing capacity of different parts in different structure under different seismic motion level shall be determined (including non-occurrence of brittle shear failure, plastic hinge forming, reaching yield value or maintaining elasticity, etc.); as well as the requirements at high, medium and low level of expected elasticity or elastoplastic deformation condition of different parts in different structure under different seismic motion level, and corresponding component ductility construction. When the bearing capacity of the component is obviously improved, corresponding tensibility construction may be decreased properly. 3.10.4
The calculation for the performance-based seismic design of the building structure shall meet
the following requirements: 1
The analytical model shall correctly and reasonably reflect the transmission route of the
earthquake action and the elasticity working state of integrity or block locating building at different seismic motion level. 2
Linear method may be adopted for elasticity analysis; for elastic-plastic analysis, equivalent
linearization method (damping increase) and statical or dynamics nonlinear analysis method may be respectively used according to the elastoplastic state expected by the performance objective. 3
Relative to elasticity analysis model, the nonlinear analysis model for the structure may be
simplified properly, but the linear analysis results of above two under frequent earthquake condition shall be basically consistent; the two-step gravity effect shall be considered and the proper elastoplastic parameters shall be determined; the bearing capacity may be calculated according to the actual section and reinforcement of the component; through the comparative analysis on the calculated results of assumption ideal elasticity, the parts of possible damage and the elastoplastic deformation degree can be found out for the components. 3.10.5
The reference object and calculation method for the performance-based seismic design of the
structure and its components may be adopted according to the provisions of Section M.1 of Appendix M. 3.11 3.11.1
Earthquake Motion Observation System of buildings
For the high-rise buildings higher than 160m, 120m and 80m for the Intensity 7, 8 and 9
respectively, the earthquake motion observation system shall be installed, so the building design shall reserve spaces for the observation equipments and relevant circuits.
15
4
Site, Subsoil and Foundation 4.1
4.1.1
Site
When selecting a constructional site, the identification as favorable plat, common plat,
unfavorable plat and hazardous plat to seismic precautionary shall be classified according to Table 4.1.1. Table 4.1.1
Classification of Favorable Plat, Common Plat, Unfavorable Plat and Hazardous Plat
Plat Type
Geological, topographical and geomorphic description
Favorable plat
Stable rock, stiff soil, or dense and wide-open, even, compacted and homogeneous, medium-stiff soil
Common plat
Plats not being favorable plat, unfavorable plat or hazardous plat Soft soil, liquefied soil; stripe-protruding spur; Lonely tall hill, steep slops, steep step, river bank or boundary of slops, Soil stratification having obviously heterogeneous distribution in plane and cause of formation, lithology, and
Unfavorable plat
state (such as abandoned river beds, loosened fracture zone of fault, and hidden swamp, creek, ditch and pit, as well as subsoil formatted with excavated and filled), plastic loess with high moisture, ground surface with structural fissure Places where landslide, avalanche, subsidence, ground fissure and debris flow are liable occur during the
Hazardous splat earthquake, and where ground dislocation may be occur at active faulted zone
4.1.2
The site class of building structures shall be classified according to the equivalent shear-wave
velocity of soil profile and the thickness of site overlying layer as guideline. 4.1.3 1
The measurement of shear-wave velocity of soil shall meet following requirements: At the stage of primary investigation, for large areas of same geologic units, the number of
borings for the shear-wave-velocity tests should not be less than 3. 2
At the stage of detailed investigation, for every building, the number of borings for shear-
wave-velocity tests should not be less than 2; when the data variance significantly, the number can be increased apropos. In the case of close-set tall building groups in one sub-zone, which built at the same geologic unit, such number may be reduced apropos but shall not be less than one for each tall building and long-span space structure. 3
For buildings assigned to Category D or to Category C with less than 10 storeys and no more
than 30m in height, when the shear-wave velocity data are not available, appropriate shear-wave velocity values are permitted to be estimated by used the known geologic conditions. In these cases, the type of soil may be classified according to Table 4.1.3 by the geotechnical description of the soil, and then the shear-wave velocity of each soil layer may be estimated within the range as per set in Table 4.1.3 based on the local experiences. 4.1.4 1
The thickness of site overlying layer shall be determined according to the following requirements: Generally, the thickness of site overlying layer shall be determined according to the distance
from the ground surface to a soil-layer level, under which the shear-wave velocity is more than 500m/s, and the shear-wave velocity of the layer under it is not less than 500m/s. 2
For a soil layer, which depth lower than 5m underground and the shear-wave velocity is more
than 2.5 times of that in above this soil layer and is not less than 400m/s, then the thickness of site 16
overlying layer may be adopted the distance from the ground surface to this layer. Table 4.1.3
Classification of Soil and Range of Shear-wave Velocity Shear-wave velocity of soil
Type of soil
Geotechnical description layer (m/s)
Rocks
Stiff, hard, and complete rocks
υs>800
Broken and comparatively broken rock; soft and comparatively soft 800≥υs>500
Stiff soil or soft sock soil rock; compact gravel soil Medium dense or slightly dense detritus,
dense or medium-dense 500≥υs>250
Medium-stiff soil gravel, coarse or medium sand, cohesive soil and silt with f ak >150kPa Slightly dense gravel, coarse or medium sand, fine and mealy sand Medium-soft soil
other than that which is loose, cohesive soil and silt with f ak ≤150kPa, fill
250≥υs>150
land with f ak >130kPa Mud and muddy soil, loose sand, new alluvial sediment of cohesive soil Soft soil
υs≤150
and silt, fill land with f ak ≤130kPa Note: f ak is the reference value (kPa) of load-bearing capacity of soils; υs is the shear-wave velocity.
3
The lone-stone and lentoid-soil with a shear-wave velocity greater than 500m/s shall be
deemed the same as surrounding soil profile. 4
The hard volcanic inter-bedded rock in the soil profile shall be deemed as rigid body and its
thickness shall be deducted from the thickness of site overlaying laver. 4.1.5
The equivalent shear-wave velocity of the soil profile (layer) shall be calculated according to
the following formulae: υse=d 0/t
t =
(4.1.5-1)
n
∑ (d / υ ) i
si
(4.1.5-2)
i =1
Where
υse ——Equivalent shear wave velocity (m/s); d 0 ——Calculated depth, in m; it shall be taken as the minor of both the thickness of site overlaying layer and 20m; t ——The transmission time of the shear-wave from the ground surface to the calculated depth; d ——The thickness of the i-th soil layer within the range of calculated depth (m); i υsi ——The shear-wave velocity of the i-th soil layer within the calculated depth (m/s); n ——Number of soil layers within the range of calculated depth.
4.1.6
The construction sites shall be classified as one of four Site-category (Category I consists
of Category I0 and I1) defined in Table 4.1.6 depend on the equivalent shear-wave velocity of soil profile and the thickness of site overlaying layer. Only the values of the reliable shear-wave velocity and/or the thickness of site overlaying layer are near to the dividing line of the listed site values in Table 4.1.6, the design characteristic period value shall be permitted to determine by the interpolation method in calculating the seismic action. 17
Table 4.1.6
Thickness of Soil Overlaying Layer for Site Classification (m)
Shear-wave velocity of rocks or Equivalent
Site-category
shear-wave velocity of soil (m/s)
I0
υs>800
0
I1
II
III
800≥υs>500
0
500≥υse>250
<5
≥5
250≥υse>150
<3
3~50
>50
υse≤150
<3
3~15
15~80
IV
>80
Note: υs refers to Shear-wave velocity of rocks.
4.1.7
When seismogenic faults exist within the site, the impact assessment on the project for the
fault shall be made, which shall meet the following requirements: 1
If one of the following conditions can be satisfied, the impact on the building structures for
the fault motion may be neglected: 1)
For Intensity lower than 8;
2)
Not holocene active faults;
3)
For Intensity 8 and 9, the depth of overlaying soil for the hidden fault is greater than 60m and 90m respectively.
2
In the event that the situation does not conform to the provisions in Item 1 of this article, the
main fault zone shall be avoided in the selection of site. The distance of avoidance should not be less than the minimum distance of avoidance specified in Table 4.1.7. If scattered Category C and D buildings with less than 3 storeys are required to be built with in the avoidance distance, the aseismic measures shall be raised at the level higher by a level, the integrity of the foundation and topside structure shall be improved, and the building must not span the fault trace. Table 4.1.7
Minimum Distance of Avoidance for Seismogenic Fault (m) Precautionary category of buildings
Intensity
4.1.8
A
B
C
D
8
Special study
200m
100m
—
9
Special study
400m
200m
—
When buildings assigned to Category C or A and B need to be constructed in unfavorable
plats, which are such as stripe-protruding spur, lonely tall hill, non-rocky or highly weathered rocky steep slop, river banks or boundary of slopes, that shall conform to follows. The countermeasures shall be made to ensure the stability of those buildings under earthquake. The amplification of design seismic parameters on the unfavorable plat shall also be taken into consideration, so that the maximum value of seismic influence coefficient shall be multiplied by the enhancement coefficient. The value of enhancement coefficient shall be determined in the range from 1.1 to 1.6 according to the actual condition of the unfavorable plat. 4.1.9
The geological investigation of the site shall be carried out as follows. To classify the plats
that are favorable, unfavorable or hazardous to seismic precautionary, to provide the Sitecategoryes of soil profile and to assess of geotechnical stability under earthquake (whither landslide, avalanche, liquefaction or ground subsidence would occur) according to the actual condition. 18
For buildings that the time-historey analysis is necessary, the relevant dynamic parameters and the thickness of site overlaying layer shall also be provided as required in design. 4.2 4.2.1
Natural Subsoil and Foundations
For the following buildings, the seismic bearing capacity check may not be carried out for the
natural subsoil and foundation: 1
Buildings, specified in this code, which the topside structure seismic check may not be
conducted. 2
Buildings without soft cohesive soil in the main load-bearing layer of the subsoil: 1)
The ordinary single-storey factory buildings and single-storey spacious houses;
2)
The ordinary masonry buildings;
3)
The ordinary civil framed buildings not more than 8 storeys and 24m in height;
4)
Multistorey frame plant building and multilayer house with seismic structural wall which the foundation load is equivalent to ones specified in item 3).
Note: Soft cohesive soil layer refers t o the soil layer, which the standard values for load-bearing capacity of subsoil are less than 80, 100 and 120kPa for Intensity 7, 8 and 9 respectively.
4.2.2
When seismic check needs to be done for natural subsoil foundations, the characteristic
combination of seismic effect shall be adopted, and the seismic bearing capacity of subsoil shall be determined by the load-bearing capacity standard value of subsoil to multiply with the seismic adjusting factor of load-bearing capacity of subsoil. 4.2.3
The seismic bearing capacity of subsoil shall be calculated according to the following formula: f aE=ζ a f a
Where
(4.2.3)
f aE ——The adjusted seismic bearing capacity of subsoil; ζ a ——The seismic adjusting factor of load-bearing capacity of subsoil, which shall be taken according to those set out in Table 4.2.3; f a ——The load-bearing capacity standard values of subsoil after depth and width adjustment, that shall be determined according to the current national standard “Code for Des ign of Building Foundations” GB 50007. Table 4.2.3
Seismic Adjusting Factor of Load-bearing Capacity of Subsoil Name and characteristic of rock and soil
Rock, dense detritus, dense gravel, course and medium sand, cohesive soil and silt with f ak ≥300kPa
ζ a 1.5
Medium dense and slightly dense detritus, medium dense gravel, course and medium sand, dense and medium dense 1.3 fine and mealy sand, cohesive soil and silt with 150kPa≤ f ak <300kPa, and hard loess Slightly dense fine and mealy sands cohesive soil and silt with 100kPa≤ f ak <150kPa, plastic loess
1.1
Mud, silty soil, loose sand, fill land, newly piled loess and streamed loess
1.0
4.2.4
When checking the vertical seismic bearing capacity of natural subsoil, the mean pressure of
foundation bottom and maximum pressure on the foundation bottom edge according to the seismic 19
effect characteristic combination shall meet the requirements of the following formulae:
Where
p≤ f sE
(4.2.4-1)
pmax≤1.2 f sE
(4.2.4-2)
p ——Mean pressure on foundational bottom according to seismic effect characteristic combination; pmax ——Maximum pressure on the foundational bottom edge according to seismic effect characteristic combination. For high-rise buildings with height-width ratio greater than 4, the foundational bottom shall have no zero stress zone under the earthquake; for other buildings, the area of zero stress zone between the subsoil and the foundational bottom shall not exceed 15% of the foundational bottom area. 4.3
4.3.1
Liquefaction and Soft Subsoil
For Intensity 6, the judged consequences of liquefaction of the saturated soil (loess not
included) and the mitigation (treatment) measures need not be considered for the ordinary buildings, but buildings assigned to Category B which is sensitive to the settlement caused by liquefaction, that may be carried out as Intensity 7. For the buildings assigned to Category B, the assessment of consequences of the liquefaction and the mitigation measures may be considered by referring to the original Intensity for Intensity 7 to 9. 4.3.2
For the subsoil inside which saturated sand and saturated silt (loess not included) exist,
the assessment of liquefaction shall be made, except where is Intensity 6; when there is liquefaction, corresponding mitigation measures shall be taken depend on the Precautionary Category, the liquefaction Grade and other actual condition. Note: For liquefaction discriminating in this article, loess and powdery clay are excluded.
4.3.3
If one of following condition is satisfied, the saturated sand and saturated silt (loess not
included) may be primary discriminated as non-liquefaction or consequences of liquefaction need not be considered: 1
The geochron of soil is Epipleistocene of Quaternary (Q3) or earlier, it may be discriminated
as non-liquefied soils for Intensity 7 to 8. 2
The percentage of contain of clay particles (diameter less than 0.005mm) in silt is not less
than 10%, 13% and 16% for Intensity 7, 8 and 9 respectively, it may be discriminated as non-liquefied soils. Note: The clay particles contain shall be determined by use of sodium hexametaphosphate as the dispersant. When other methods are be used, it shall be correspond conversed in according to relative provisions.
3
For buildings with shallow-depth natural subsoil, the consequences of liquefaction need not
be considered when the thickness of the overlaying non-liquefiable soils and the elevation of groundwater table comply with one of the following conditions: d u>d 0+d b－2
(4.3.3-1)
d w>d 0+d b－3
(4.3.3-2) 20
d u+d w>1.5d 0+2d b－4.5 Where
(4.3.3-3)
d w ——Elevation of groundwater table (m), for which the mean annual highest elevation during the reference period should be used, or the annual highest elevation in recent years may also be used; d u ——Thickness of the overlaying non-liquefiable layer (m) , in which the thickness of mud and silt seams should be deduced; d h ——Foundational depth (m), when it is less than 2m, shall equal 2m; d 0 ——Reference depth of liquefaction soil (m), it may be taken according to those set out in Table 4.3.3. Table 4.3.3
Reference Depth of Liquefaction Soil (m)
Type of saturated soil
Intensity 7
Intensity 8
Intensity 9
Silt
6
7
8
Sand
7
8
9
Note: When the underground water level in this region is under variable condition, the reference depth shall be considered according to the unfavorable condition.
4.3.4
If the preliminary discrimination of saturated sandy soil and silt indicate further liquification
discriminating, standard penetration test shall be adopted to discriminate the liquification condition of the soil within 20m (deep) underground; but for the buildings that Article 4.2.1 of this code specifies no seismic bearing capacity checking Calculation for natural subsoil and foundation, the liquification condition of the soil within only 15m (deep) underground is conducted. When the blow count of saturated soil standard penetration (without pole length correction) is less than or equal to the blow count critical value of the liquification discriminating standard penetration blow count, the soil is judged as liquification soil. If matured experiences are available, other discriminating methods may be adopted. The blow count critical value of the liquification discriminating standard penetration blow count, for the soil within 20m (deep) underground, may be calculated according to following formula: N cr = N 0 β [ln(0.6d s+1.5)－0.1d w] 3 / ρ c Where
(4.3.4)
N c ——Critical value of Standard Penetration Resistance (blow-number) for liquefaction r discrimination; N 0 ——Reference value of Standard Penetration Resistance (blow-number) for li quefaction discrimination, it shall be taken according to those set out in Table 4.3.4; d s ——Depth of standard penetration for saturated soil (m); d w ——Underground water level (m); ρc ——Percentage of clay particle content; when it is less than 3 or when the soil is sand, the value shall be equal to 3; β ——Adjustment coefficient, 0.80 for design earthquake group 1, 0.95 for group 2, and 1.05 for group 3. 21
Table 4.3.4
Reference Value (N0) of Standard Penetration Blow Count in Liquification Discriminating Design basic seismic acceleration ( g )
0.10
0.15
0.20
0.30
0.40
Reference value of standard penetration blow count in liquification discriminating
7
10
12
16
19
For the subsoil with liquefied soil layers, the level and thickness of soil layer shall be explored
4.3.5
and the liquefaction index shall be calculated by the following formula, and then the liquefaction Grades shall be comprehensively classified according to Table 4.3.5:
I lE =
n
i =1
Where
N i
∑ [1 − N
]d i wi
(4.3.5)
cr i
I l E ——Liquefaction index; n ——Total number of standard penetration test points in each bore within the discriminated depth under the ground surface;
N i, N cr ——Measured value and critical value of standard penetration resistance (blow-number) i at the i-th point respectively, when the measured value is greater than the critical value, shall take as equal critical value; when only the liquefaction within 15m in depth is discriminated, the measured values under 15m may be adopted as the critical value; d ——Thickness of soil layer (m) at the i-th point, it may be taken as half of the difference i in depth between the upper and lower neighboring Standard Penetration Test points; but the upper point level shall not be less than the elevation of groundwater table, and the lower point level not greater than the liquefaction depth; W ——Weighted function value of the i-th soil layer (m 1), which is considered the affect of i －
the layer portion and level of the unit soil layer thickness. Such value is equal 10 when the depth of the midpoint of the layer is less than 5m; it is zero when it equals 20m; and it is valued by linear interpolation when it is between 5m and 20m. Table 4.3.5
Liquefaction Grade of and Liquefaction Index
Grades of liquefaction
Light
Moderate
Serious
Liquefaction index
0< I lE ≤6
6< I lE ≤18
I lE >18
4.3.6
For the even liquefied soil layer, the liquefaction mitigation measures shown in Table 4.3.6
may be selected; and the affect of the gravity for structural system may also be considered to adjust above liquefaction mitigation measures. The liquefied soil layer, which mitigation measure such as ground stabilization has not made, should not be used as bearing stratum of the footings. 4.3.7
The measures to eliminate completely the differential settlement due to liquefaction shall meet
the following requirements: 1
When pile foundation is used, the length (pile-tip not included) of the pile driven into the
stable soil layer below the liquefaction depth shall not be less than 0.8m for detritus, gravel, coarse and medium sand, stiff cohesive soil, and dense silt; it should not be less than 1.5m for other nonrocky soil. 2
When deep foundations are used, the depth of the foundational bottom embedded in the 22
stable soil layer below the liquefaction depth shall not be less than 0.5m. Table 4-3-6
Liquefaction Mitigation Measures Grades of liquefaction of subsoil
Precautionary Category
Light
Moderate
Serious
Differential settlement due to
Differential settlement due to
liquefaction to be partially eliminated,
liquefaction to be completely or
Differential settlement due to liquefaction to
or design of foundation and upside
partially eliminated, and design of
be completely eliminated
structure
foundation and upside structure
Design of foundation and upside
Adjusted design of foundation and
structure, or mitigation measures may
structural systems, or other more
not be taken
strict measures may be taken
B
Differential settlement due to liquefaction to be completely eliminated, or partially to be C
eliminated together with design of foundation and upside structure D
Mitigation measures may not be
design of foundation and upside structure, or
taken
other low-cost measures may be taken
Mitigation measures may not be taken
Note: The special study shall be conducted for the liquification resistance measured of subsoil of Category A building, and it shall not be lower than corresponding requirements of Category B building.
3 When a compaction method is used for strengthening (e.g. vibrating impact, vibrating compaction,
sand or detritus pile compaction, and strong ramming), compaction shall be carried out down to the lower margin of liquefaction depth. After strengthening, the measured value of the standard penetration resistance (in number) of soils shall be greater than the corresponding critical value of provision in Article 4.3.4 of this code. 4
Replacing all the liquefaction soil layers with non-liquefaction soil, or increasing the thickness
of non-liquefiable soils over covered. 5
When the compaction method or removal of liquefiable soil methods are adopted, the
strengthened width outside the foundation edge shall exceed 1/2 of its depth under the foundation bottom; more, the width shall not be less than 1/5 of the foundation width. 4.3.8
The measures to eliminate partially the differential settlement due to liquefaction shall meet
the following requirements: 1
The compacted or removal shall be carried out to a depth so that the liquefaction index of the
subsoil shall be reduced. The liquefaction index should not be larger than 5; for central zone of large raft or box foundation, the liquefaction index here of may be reduced to 4; for individual footings (foundation) and strip footings, it shall also not be less than the reference depth of liquefaction soil and the maximal width of the foundation. Note: Central zone refers to the region located within the foundation outer edge, and within over 1/4 length along the length/width direction away from the outer edge.
2
In the range of the above depth, the liquefaction soil layers shall be strengthened by
compaction, so that the measured value of the Standard Penetration Resistance (in blow-number) of the compacted soil layer should be more than the corresponding critical value of provision in Article 4.3.4 of this code. 3
The strengthened width outside the foundation shall conform to the requirements in Item 5 of
Article 4.3.7 of this code. 23
4
Other measures to reduce shock subsidence due to liquefaction, like thickening upper covered
non-liquefied soil layer and improving the peripheral drainage condition. 4.3.9
For treatment of the foundation and the structural system, the following mitigation measures
can be taken one or more to reduce the affect of liquefaction based on comprehensive considerations: 1
Select the appropriate buried depth of foundation.
2
Adjust the foundation bottom area to reduce the eccentricity of the foundation.
3
Increase the integrality and rigidity of the foundation, for example, the use of box- shape
foundation or raft footing, the use of cross-strip footing, adding foundation ring-beams or connecting beams. 4
Decrease the load, increase the integrality, uniformity and symmetry of the structural system,
install rational settlement joints, and avoid the use of a structural configuration that is vulnerable to non-uniform settlement. 5
At locations where pipelines pass through the building, sufficient space shall be left beforehand
for the pipelines, or flexible pipe connections shall be used. 4.3.10 No permanent buildings should be constructed within the sections of river or sea bank and
slope with side-expending liquefaction, or with possible sliding; otherwise, anti-sliding checks shall be carried out, and anti-sliding measures for the earth and anti-cracking measures for the structure shall be taken. The following method may be adopted to discriminate the shock subsidence of soft tenacity
4.3.11
soil layer in subsoil. The shock subsidence resistence measures and the hazards of saturated powdery clay shall be determined by synthetic study according to the factors such as degree of subsidence and lateral deformation. the powdery clay, at Intensity 8 (0.30 g ) and Intensity 9, with the plasticity index less than 15 and meeting the requirements of the following formula, may be judged as shock subsidence soft soil.
Where
W s≥0.9W L
(4.3.11-1)
I L≥0.75
(4.3.11-2)
W s ——Natural moisture content; W L ——Liquid limit water content, tested by liquid and plastic limit combined test; I L ——Liquidity factor.
4.3.12
If the main load-bearing stratum inside which the soft cohesive soil or collapsible loess exists,
the measures that are such as adoption of pile foundation, strengthening of subsoil or those measures in Article 4.3.9 of this code, shall be taken based on the comprehensive consideration the actual conditions. And corresponding mitigation measures may also be taken based on the estimation of the settlement under earthquake. 4.4 4.4.1
Pile Foundation
For the following buildings, the pile foundation, with low pile caps and mainly resisting
vertical load but without liquefaction soil, mud, silt soil or backfill soils with standard value of load bearing capacity not greater than 100kPa, may not be check for the seismic bearing capacity: 24
1
2 4.4.2
The following buildings for Intensity 7 and 8: 1)
Ordinary single-storey factory buildings or single-storey spacious buildings;
2)
Ordinary framed civil buildings with not exceed 8 storeys and 24m in height;
3)
Multi-storey framed factory with foundation load equivalent to that in Item 2).
Buildings as specified in Item 1 and 3 of Article 4.2.1 of this code. The seismic check of pile foundation with low pile caps in non-liquefaction soil shall meet the
following requirements: 1
The seismic bearing capacity standard values in the vertical and horizontal direction of a
single pile may both increase by 25% than that is required for non-seismic designs. 2
When the dry density of tamped backfill around the pile cap satisfying (not lower) the
requirements for backfill, which provision in “Code for Design of Building Foundations” GB 50007, the pile and its front backfill soil may together resist the horizontal seismic action. However, the friction between the bottom surface and the subsoil shall not be taken into account. 4.4.3
The seismic check of pile foundation with low pile cap in the liquefaction soil shall meet the
following requirements: 1
For the ordinary shallow foundations, the resistance of the pile cap surrounding soil and the
horizontal seismic-resistance of the rigid ground floor should not be taken into account. 2
When there is non-liquefaction soil or non soft soil layer with the thickness of 1.5m and 1.0m
in the upper and lower pile cap, the seismic check may be carried out according to the following two cases, and the design shall be carried out according to unfavorable conditions: 1)
The pile designed to resist all the seismic action, and the bearing capacity of the pile shall be determined from Article 4.4.2 of this code, but the friction and the horizontal resistance of the pile in liquefaction soil shall all multiplied by the reduction factor defined in Table 4.4.3. Table 4.4.3
Reduction Factor for the Liquefaction Effect of Soil Layer
Ratio of actual and critical Standard Penetration blows
Depth d s (m)
Reduction factor
d s≤10
0
10
1/3
d s≤10
1/3
10
2/3
d s≤10
2/3
10
1
≤0.6
>0.6~0.8
>0.8~1.0
2)
The seismic action shall be determined according to 10% of the maximum value of horizontal seismic influence coefficient, which provision in this code. And the pile bearing capacity shall be determined from Item 1 in Article 4.4.2 of this code, but all of the friction, in the liquefaction soil and in the non-liquefaction soil within the depth of 2m under the pile cap, shall be deducted.
3
For hammered and other driving piles, when the pile center-to-center mean spacing is 2.5 to 4 25
times of pile diameters and the pile group is not less than 5×5, the compacting effect for driving piles and the favorable affect of the pile on restricting the soil deformation may be taken into consideration. When the Standard Penetration Resistance (blow-number) of soil around pile meet the requirements for non-liquefaction, the bearing capacity of single pile may not be reduced, however, when checking the capacity of the pile-tip bearing stratum, the diffusion angel outside the pile group shall be taken as zero. The Standard Penetration Resistance (blow-number) on the soil around the pile after pile driving should be determined by tests, and may also be determined according to the following formula: N 1= N p+100 ρ(1－ e Where
−0.3 N p
)
(4.4.3)
N 1 ——The Standard Penetration Resistance (blow-number) after pile driving; ρ ——Ratio of the area conversion for piles to soils; N p ——The Standard Penetration Resistance (blow-number) before pile driving.
4.4.4
The area around the pile cap in liquefaction soils should be tamped with non-liquefiable soil; if
sand or silty-soil are used, the Standard Penetration Resistance (blow-number) of the soil layer shall not be less than the critical value for liquefaction of provisions in Article 4.3.4 of this code. 4.4.5
The reinforced range of the pile in liquefaction soil shall cover from the top of the pile to
depth under the liquefaction soil, comply with the required depth for eliminate completely the different settlement due to liquefaction. In within, the longitudinal reinforcement shall be the same as the top of the pile, the stirrups shall be densified. 4.4.6
In plats where exist lateral movement due to liquefaction, the pile foundation, besides satisfy
other provisions set forth in this section, shall also be considered with the lateral-force due to soil-flow. Moreover, the area bearing lateral-force shall be calculated according to the distance between the both of side-piles outer-edges.
26
5
Seismic Action and Seismic Checking for Structures 5.1
5.1.1
General Requirements
Seismic action of every building structure shall be considered in accordance with the
following principles: 1
Generally, the horizontal seismic actions should at least considered and checked separately
along the two orthogonal major axial directions of the building structure; and that horizontal seismic action shall be resisted by all of the corresponding direction lateral-force-resisting components. 2
Structures having the oblique direction lateral-force-resisting components and the oblique
angel to major orthogonal axes is greater than 15°, the horizontal seismic action along the direction of each lateral-force-resisting component shall be considered respectively. 3
Structures having obvious asymmetric mass and rigidity distribution, the torsion effects
caused by both two orthogonal horizontal direction seismic action shall be considered; and other structures, it is permitted that methods, such as adjusting the seismic effects method, to consider they seismic torsion effects. 4
Large-span structures and long-cantilevered structures for Intensity 8 or 9, and tall
buildings for Intensity 9, vertical seismic action shall be considered. Note: For building structures adopting seismic-isolated designs for Intensity 8 and 9, the vertical seismic action shall be calculated according to relevant provisions in this code.
5.1.2 1
The following methods shall be taken for seismic computation of any building structure: For structures, which not higher than 40m and having deformations predominantly due to
shear and a rather uniform distribution of mass and rigidity in elevation, or for structures modeled as a single-mass system, a simplified method, such as the base shear method, may be used. 2
For building structures other than those as stated in the above item, the response spectrum
method for modal analysis should be used. 3
For buildings having extremely irregular configuration, buildings assigned Precautionary
Category A, and tall buildings with in the height range given in Table 5.1.2-1, a time-historey analysis method under Frequently Earthquake shall be used as an additional computation. When adopting input of acceleration time-historey curves in 3 groups, the greater value between the average value of the time-historey calculation results and the result of the response spectrum method should be adopted; when adopting curves in 7 or more groups, the greater value between the average value of the timehistorey calculation results and the result of the response spectrum method may be adopted. When the time-historey method is adopted in the analysis, the acceleration time-historey curves of actual strong earthquake records and artificial simulation shall be selected according to building site type and design seismic zoning. At least 2/3 of strong earthquake records shall be provided. Their average seismic influence coefficient curve shall be in conformity with the seismic influence coefficient curve when adopting the response spectrum method, the maximum value for its acceleration timehistorey may be adopted according to Table 5.1.2-2. When adopting elastic time-historey analyzing 27
method, the structure base shear force obtained from each time-historey curve shall not be less than 65% of that from the response spectrum method, and the average value from several time-historey curves shall not be less than 80% of that from the response spectrum method. Table 5.1.2-1
Building Height Range for Using Time-historey Analysis Method
Intensity and Site-category
Range of building height (m)
Intensity 7; Intensity 8 with Site-category I, II
>100
Intensity 8 with Site-category III, IV
>80
Intensity 9
>60
Table 5.1.2-2
Maximum Value for the Seismic Acceleration of Ground Motion Used in Time-historey Analysis
(cm/s2) Seismic action
Intensity 6
Intensity 7
Intensity 8
Intensity 9
Frequently Earthquake
18
35 (55)
70 (110)
140
Rare Earthquake
125
220 (310)
400 (510)
620
Note: Values in the brackets are used that the design basic acceleration of ground motion is 0.15 g and 0.30 g respectively.
4
When calculating the deformation of the structure under rare earthquake, the simplified
elasto-plastic analyzing method or elasto-plastic time-historey analyzing methods shall be adopted in accordance with the provisions in Section 5.5 of this code. 5
For the structure with larger horizon projection are, the seismic calculation shall be conducted
in the input mode of simple point uniformity, multi-point and multiway simple point or multiway multi-points according to the structure form and support condition. in multi-points input calculation, the travelling earthquake wave effect and local site effect shall be considered. on Category I and II site with Intensity 6 and 7, the calculation method may be simplified for the seismic checking of supporting structure, topside structure and foundation; according to different structure span and length, the short side of the component may be multiplied with the additional earthquake action effect coefficient 1.15~ 1.30; in the seismic checking for Category III and IV with Intensity 7, time interval analytical method shall be adopted. 6
In the seismic isolation and energy dissipation /shock absorption design of building structures,
the calculation method specified in Chapter 12 shall be adopted. 7
For underground construction structure, the calculation method specified in Chapter 14 shall
be adopted. 5.1.3
In the computation of seismic action, the representative value of gravity load of the
building shall be taken as the sum of standard values of the weight of the structure and components plus the combination values of variable loads on the structure. The combination coefficients for different variable loads shall be taken according to Table 5.1.3. 5.1.4
Seismic influence coefficient of a building structure shall be determined according to
Intensity, site-category, design seismic group, and natural period and damping ratio of the structure. The maximum value of horizontal seismic influence coefficient shall be taken according to Table 5.1.4-1; the characteristic period shall be taken according to Table 5.1.4-2 in the light of Site-category and Design Seismic Group, and that shall be increased 0.05s for Rare Earthquake of Intensity 8 and 9. Note: The seismic influence coefficient shall be studied specifically that building structures with period greater than 6.0s.
28
Table 5.1.3
Combination Coefficient
Type of variable load
Combination coefficient
Snow load
0.5
Dust load on the roof
0.5
Active load on the roof
Not considered
Active load on the floor, calculated according to actual state
1.0
Active load on the floor, calculated according to
Library, Archives
0.8
equivalent uniform load
Other civil buildings
0.5
Hanger with hard hooks
0.3
Hanger with flexible hooks
Not considered
Gravity for hanging object of crane Note: When the hanging weight is bigger, the combination coefficient shall be adopted according to the actual condition.
Table 5.1.4-1
Maximum Value of Horizontal Seismic Influence Coefficient
Earthquake influence
Intensity 6
Intensity 7
Intensity 8
Intensity 9
Frequently earthquake
0.04
0.08 (0.12)
0.16 (0.24)
0.32
Rare earthquake
0.28
0.50 (0.72)
0.90 (1.20)
1.40
g and 0.30 g . Note: The values in the brackets are separately used f or where the design basic seismic acceleration is 0.15
Table 5.1.4-2
Characteristic Period Value (s)
Design Seismic Group
I0
I1
II
III
IV
Group 1
0.20
0.25
0.35
0.45
0.65
Group2
0.25
0.30
0.40
0.55
0.75
Group 3
0.30
0.35
0.45
0.65
0.90
5.1.5
The damping adjusting and forming parameters on the building seismic influence coefficient
curve (Figure 5.1.5) shall meet the following requirements: 1
The damping ratio of building structures shall select 0.05 except otherwise provided, the
damping adjusting coefficient of the seismic influence coefficient curve shall select 1.0, and the coefficient of shape shall meet the following requirements: 1)
Linear increase section, whose period is less than 0.1s;
2)
Horizontal section, whose period from 0.1s thought to characteristic period, shall select the maximum value (amax);
3)
Curvilinear decrease section, whose period from characteristic period thought to 5 times of the characteristic period, the power index shall choose 0.9;
4)
Linear decrease section, whose period from 5 times characteristic period thought to 6s, the adjusting factor of slope shall choose 0.02.
2
When the damping ratio of building structures is not equal to 0.05 according to relevant
provisions, the damping adjusting and forming parameters on the seismic influence coefficient curve shall meet the following requirements: 1)
The power index of the curvilinear decrease section shall be determined according to the following formulae: 29
Figure 5.1.5
Seismic Influence Coefficient Curve
a —Seismic influence coefficient; amax —The maximum value of seismic influence coefficient; η1 —Adjusting coefficient of declined slope at straight-line declining section; γ —Attenuation index number; T g —Haracteristic period; η2 —Damping adjusting coefficient; T —Natural period of vibration for structure
γ = 0.9 +
Where
0.05 − ζ 0.5 + 5ζ
(5.1.5-2)
γ ——The power index of the curvilinear decrease section; ζ ——The damping ratio. 2)
The adjusting factor of slope for the linear decrease section shall be determined according to the following formula: η1=0.02+(0.05－ζ )/(4+32ζ )
Where
(5.1.5-2)
η1 ——The adjusting factor of slope for the linear decrease section, when it is less than 0, shall equal 0. 3)
The damping adjustment factor shall be determined according to the following formula:
η 2 = 1 +
Where 5.1.6 1
0.05 − ζ 0.06 + 1.6ζ
(5.1.5-3)
η2 ——The damping adjustment factor, when it is smaller than 0.55, shall be equal to 0.55. The seismic check of the building structure shall comply with the following requirements: Only the buildings assigned to Precautionary Intensity 6 (expect irregular building and
higher buildings built on site-category IV), as well as unfired earth house and wood house, the seismic checking of cross section of structural components shall be permitted to not carry out. However the relevant seismic details requirements for those buildings shall be satisfied, and the seismic checking of cross section may not be carried out. 2
For irregular buildings and higher buildings located on on site-category IV at Intensity
6, as well as the building structures (expect unfired earth house and wood house) at Intensity 7 and above, the seismic checking of cross section shall be carried out under frequently earthquakes. Note: The seismic check of building structures adopting seismic-isolation design shall comply with relevant provisions.
5.1.7
For structures conforming to the provisions in Section 5.5 of this code, be sides carrying out
cross section seismic check, corresponding deformation check shall also be carried out. 30
5.2
Calculation of Horizontal Seismic Action
When the base shear force method is used, only one degree of freedom may be considered for
5.2.1
each storey; the standard value of horizontal seismic action of the structure shall be determined according to the following formulae (Figure 5.2.1):
Figure 5.2.1
Sketch for Computation of the Horizontal Seismic Action
F EK =α1Geq
F i =
Gi H i n
∑ G H j
F EK ( 1 − δn )
(5.2.1-1) (i=1, 2,…n)
(5.2.1-2)
j
j =1
Δ F n=δn F EK Where
(5.2.1-3)
F Ek ——Standard value of the total horizontal seismic action of the structure; a1 ——Horizontal seismic influence coefficient corresponding to the fundamental period of the structure, which shall be determined according to Article 5.1.4 and Article 5.1.4 of this code. For multi-storey masonry buildings and multi-storey masonry buildings with bottom-frames, the maximum value of horizontal seismic influence coefficient should be taken; Geq ——Equivalent total gravity load of a structure. When the structure is modeled as a single-mass system, the representative value of the total gravity load shall be used; and when the structure is modeled as a multi-mass system, 85% of the representative value of the total gravity load may be used; F ——Standard value of horizontal seismic action applied on the i-th mass; i Gi, G j ——Representative values of gravity load concentrated at the i-th and j-th masses respectively, which shall be determined according to Article 5.1.3 of this code;
H i, H j ——Calculated height of the i-th and j-th masses from the base of the building respectively; δn ——Additional seismic action factors at the top of the building; for multistorey reinforced concrete buildings, it may be taken according to Table 5.2.1; for other buildings, a value of 0.0 may be used; Δ F n ——Additional horizontal seismic action applied at top of the building. 31
Table 5.2.1
Additional Seismic Action Factors at Top of the Building T 1≤1.4T g
T g (s)
T 1>1.4T g
T g≤0.35
0.08T 1+0.07
0.35
0.08T 1+0.01
T g>0.55
0.08T 1－0.02
0.0
Note: T 1 is the fundamental period of the structure.
5.2.2
When the response spectrum method is used for model analysis, if the torsion coupling effect
of a structure is not considered, the seismic action and its effect shall be calculated according to the following requirements: 1
The standard value of horizontal seismic action on the i-th mass of the structure, corresponding
to j-th mode, shall be determined according to the following formulae: (i=1, 2,…n, j=1, 2,…m)
F ji=α jγ j X jiGi
γ j =
n
n
∑ X G / ∑ X G ji
i =1
Where
(5.2.2-1)
2 ji
i
i
(5.2.2-2)
i =1
F ji ——Standard value of horizontal seismic action of the i-th mass corresponding to mode j-th; α j —— Seismic influence coefficient corresponding to the natural period of mode j-th of the structure, determined by Article 5.1.4 and 5.1.5 of this code; X ji —— The horizontal relative displacement of the i-th mass of the j-th vibration mode; γ j ——Mode participation factor of mode j-th.
2
The effect of the horizontal seismic action (bending moment, shear, axial force, or deformation)
shall be determined according to the following formula, when the period of adjacent mode is less than 0.85:
S Ek = ΣS 2j Where
(5.2.2-3)
S Ek ——Effect caused by the horizontal seismic action standard value; S j ——Effect caused by the horizontal seismic action of mode j-th, and only the first 2~3 modes may be taken. When the fundamental natural period is greater than 1.5s, or the ratio of height to width of the building exceeds 5, number of modes used shall be increased in the computation.
5.2.3
Under the horizontal earthquake actions, the torsion coupling seismic effect of building
structure shall meet the following requirements: 1
When no coupled torsion calculation is to be carried out for regular structures, the action
effect of the two side trusses of structure parallel to the earthquake action direction shall be multiplied by the amplifying coefficient. In one word, the short side may select the factor 1.15, and the longer side may choose the factor 1.05; when the torsion rigidity of structure is smaller, it should appropriate to select the factor as 1.3. As for the member at corners, the action effect should be multiplied by the 32
amplifying coefficient in two directions simultaneously. 2
When calculating according to coupled torsion method, three degrees of freedom may be
selected for each floor, including two orthogonal horizontal deformations and a rotation around the vertical axis, and the seismic action and its effect shall be calculated according to the following formula. When there are sufficient reasons, other simplified methods may also be used in determining the seismic effect. 1)
The horizontal seismic action standard value in the i-th floor for j-th mode of natural vibration of structure shall be determined according to the following formulae: F x ji=α jγtj X jiGi F y ji=α jγt jY jiGi (i=1, 2,…n, j=1, 2,…m) F t ji=α jγt j r i 2ϕ ji Gi
(5.2.3-1)
Where F x ji, F y ji, F t ji ——The seismic action standard value of floor i-th for mode j-th of natural vibration of structure in direction of x, y and rotation respectively; X ji, Y ji ——The horizontal relative displacement of the center of floor i-th for mode j-th of natural vibration of structure in direction of x, y respectively; φ ji ——Relative rotation angle of floor i-th for mode j-th of natural vibration of structure; r ——The rotating radius of floor i-th, which is the square root of that the rotating i moment of inertia around the center of floor i-th divided by the mass of this floor; γij ——Mode participation factor of mode j-th considering rotation effect, that may be determined in accordance with the following formulae: When only the seismic action in x direction is considered
γ tj =
n
n
∑ X G / ∑ (X ji
2 ji
i
i =1
+ Y ji2 + ϕ ji2 r i 2 )Gi
(5.2.3-2)
i =1
When only the seismic action in y direction is considered
γ tj =
n
n
∑
∑ (X
i =1
i =1
2 ji
X ji Gi /
+ Y ji2 + ϕ ji2 r i 2 )Gi
(5.2.3-3)
When the seismic action oblique with x direction is considered
γ t j = γ x j cos θ + γ yj sin θ Where
(5.2.3-4)
γx j, γy j ——The participation factors define by formulae (5.2.3-2) and (5.2.3-3) respectively; θ ——Angle between the seismic action direction and x direction. 2)
The torsion effect of single direction horizontal seismic action may be determined in 33
accordance with following formulae:
S Ek =
m
m
∑∑ ρ
S S k
(5.2.3-5)
jk j
j =1 k =1
ρ jk = Where
8 ζ jζ k (ζ j + λ Tζ k )λ 1.5 T (1 − λ 2T ) 2 + 4ζ jζ k (1 + λ T ) 2 λ T + 4(ζ j2 + ζ k 2 )λ 2T
(5.2.3-6)
S Ek ——Torsion effect caused by the seismic action standard value; S j, S k ——The effect caused by seismic action of modes j-th and k -th respectively, the first 9~15 mode may be selected; ζ i, ζ k ——The damping ratio of modes j-th and k -th respectively; ρ jk ——Coupling factor of modes j-th and k -th; λT ——Ratio between the natural periods of modes k -th and j-th. 3)
The torsion effect of double direction horizontal seismic action may be determined in accordance with following formulae, and the larger result shall be adopted:
Or Where
S Ek =
S x2 + (0.85S y ) 2
(5.2.3-7)
S Ek =
S y2 + (0.85S x ) 2
(5.2.3-8)
S x, S y ——The torsion effects caused by horizontal seismic action along x and y directions determined in accordance with Formula (5.2.3-5) respectively.
5.2.4
When the base shear method is used, the seismic effect of penthouse, parapet and chimney on
the roof should be multiplied by an enhancement coefficient of 3; such increase part of effect shall not be assigned to the lower part of the structure. But the parts connected with the projecting part shall be considered. When modal analysis method is used, the projecting part may be considered as one mass. The enhancement coefficient of seismic effect of the projecting skylight frame of a single-storey factory building shall comply with relevant provisions in Chapter 9 of this code. 5.2.5
The horizontal seismic shear force at each floor level of the structure shall be comply
with the requirement of the following formula: n
∑G
V Ek i > λ
j
(5.2.5)
j =1
Where
V Ek ——The floor i -th shear corresponding to horizontal seismic action standard value; i λ ——Shear factor, it shall not be less than values specified in Table 5.2.5; for the weak location of vertical irregular structure, these values shall be multiplied by the enhancement coefficient of 1.15; G j ——The representing value of gravity load in floor j -th of the structure. 34
Table 5.2.5
Minimum Seismic Shear Factor Value of a Floor
Structures
Intensity 6
Intensity 7
Intensity 8
Intensity 9
0.008
0.016 (0.024)
0.032 (0.048)
0.064
0.006
0.012 (0.018)
0.024 (0.036)
0.048
Structures with obvious torsion effect or fundamental period is less than 3.5s Structures with fundamental period greater than 5.0s Note: 1 2
5.2.6
The values may be selected through interpolation method for structures whose basic period is between 3.5s and 5s; g and 0.30 g respectively. Values in the brackets are used at the regions with basic seismic acceleration as 0.15
The horizontal seismic shear force at each floor level of the structure shall be distributed
according to the following principles: 1
For buildings with rigid diaphragms, such as cast-in-situ and monolithic-prefabricated concrete
floors and roof, the distribution should be done in proportion to the equivalent rigidity of the lateralforce-resisting components. 2
For buildings with flexible diaphragms, such as wood roof and wood floors, the distribution
should be done according to the ratio of gravity load representative value on the areas which are subordinated the lateral-force-resisting components. 3
For buildings with semi-rigid diaphragms, such as ordinary prefabricated concrete roof and
floors, the distributed may select the average value of the above two methods. 4
The above distribution results may be adjusted in accordance with the relevant provisions in
this code, to consider the interaction of the lateral-force-components, deformation of diaphragms, elasto-plastic deformation of the seismic wall, and torsion response. 5.2.7
In the seismic computation of a structure, in general, the subsoil-structure interaction may be
ignored; if the subsoil-structure interaction of reinforced concrete tall buildings for Intensity 8 and 9 and with Site-category III or IV is need to consider, that shall comply with following requirements. The tall building structures with caisson or a relatively rigid raft foundation or caisson-pile foundation; and the fundamental period of the structure is within the scope of 1.2 to 5 times of the characteristic period of Site. If the subsoil-structure interaction is considered for those structures, the horizontal seismic shear forces assumed for rigid base may be reduced in accordance with the following provisions, and the storey drift may be calculated according to the reduced storey shear force. 1
In structures with height-width ratio less than 3, the reduction factor of horizontal seismic
shear of each floor may be determined according to following formula:
=(
Where
T 1
) 0.9 T 1 + ΔT
(5.2.7)
——Seismic shear reduction factor considering the subsoil-structure interaction; T 1 ——The fundamental period of the structure, with determined by assumption of the rigid base (s); ΔT——The additional period after considering the subsoil-structure interaction (s), that may be determined according to Table 5.2.7.
2
For structures whose height-width ratio is not less than 3, the seismic shear of the structural 35
bottom may be reduced according to Item 1 of this article, that of the top may not reduced, and that of the middle floors may be reduced according to the linear interpolation values. Table 5.2.7
Additional Period (s) Site-category
Intensity
3
Category III
Category IV
8
0.08
0.20
9
0.10
0.25
The reduced horizontal shear of all floors shall meet the requirements of Article 5.2.5 of this
code. 5.3 5.3.1
Calculation of Vertical Seismic Action
For tall buildings for Intensity 9, the standard value of vertical seismic action shall be
determined by the following formulae (Figure 5.3.1). The effects of vertical seismic action at the floor level may be distributed in proportion of the representative value of gravity load acting on the components, which should multiply with the enhancement coefficient 1.5.
F Evk = avmax Geq
F vi =
Where
Gi H i
∑
G j H j
F Evk
(5.3.1-1)
(5.3.1-2)
F Evk ——Standard value of the total vertical seismic actions of the structure; F v ——Standard value of vertical seismic action applied on level of mass i-th; i avmax ——Maximum value of vertical seismic influence coefficient, which may be taken as 65% of the maximum value of the horizontal seismic influence coefficient; Geq ——Equivalent total gravity load of the structure, which may be taken as 75% of the representative value of the total gravity load of the structure.
Figure 5.3.1
5.3.2
Sketch for the Computation of Vertical Seismic Action
For a regular flat lattice truss roof and for trusses with span and length larger than the value
specified in Item 5 of Arricle 5.1.2 of this code and frame and roof transverse beam and bracket with a span larger than 24m, the standard value of vertical seismic action may be taken as the product of the 36
representative value of the gravity load and the coefficient of vertical seismic action. Values for the coefficient of vertical seismic action may be determined according to Table 5.3.2: Table 5.3.2
Coefficients of Vertical Earthquake Action Site-category
Type of structure
Intensity I
II
III, IV
8
May be no calculated (0.10)
0.08 (0.12)
0.10 (0.15)
9
0.15
0.15
0.20
8
0.10 (0.15)
0.13 (0.19)
0.13 (0.19)
9
0.20
0.25
0.25
Flat lattice truss, Steel truss
Reinforcement concrete truss Note: The values in the brackets are used to design for regions where the basic seismic acceleration is 0.30 g .
5.3.3
For long cantilever and other large-span structures (not specified in Article 5.3.2 of this code)
for Intensity 8 and 9, the vertical seismic action standard value may be taken as 10% and 20% of the gravity load representative values of structure or component respectively. When the design basic seismic acceleration is 0.30 g , that may be taken as 15% of the gravity load representative value of structure or component. 5.3.4
The vertical earthquake action of the wide span space structure may be calculated by the
vertical modal decomposition response spectrum method. The vertical seismic influence coefficient hereof may be 65% of the horizontal seismic influence coefficient specified in Article 5.1.4 and 5.1.5 of this code, but it shall be used according to the first design group. 5.4 5.4.1
Seismic Checking for Cross Section of Structural Components
The combination of seismic effect tand other loads effects on structural components shall
be calculated according to the following formula: S =γG S GE+γEh S Ehk +γEv S Evk +ψ wγw S wk Where
(5.4.1)
S ——Design value of combination of inner forces in a structural component, including design value of combination of bending moment, axial force and shear force; γG ——Partial factor of gravity load, which shall be taken as 1.2 in ordinary conditions; when the effect of gravity load is favorable to the bearing capacity of the component, that not larger than 1.0;
γEh, γEv ——Partial factors for horizontal and vertical seismic action respectively, which shall be determined according to Table 5.4.1; γw ——Partial factor for wind load, which shall be taken as 1.4; S GE ——Effects for representative value of gravity load (that may be selected according to Article 5.1.3 of this code), in which shall be included the standard value of the all hanging weight for the crane; S Ehk ——Effects for standard value of seismic action in horizontal direction, that shall be multiplied by the relevant enhancement coefficient or adjusted factor; S Evk ——Effects for standard value of seismic action in vertical direction, that shall be multiplied by the relevant enhancement coefficient or adjusted factor; 37
S wk ——Effects for standard value of wind load; ψ w ——Coefficient for combination value of wind load, that shall be taken as 0.0 for ordinary structures, and taken as 0.2 for tall building structures that the wind load is control load. Note: Generally, the suffix to indicate the direction is neglected in this code.
Table 5.4.1
Seismic Action Partial Coefficients
Seismic action
γEh
γEv
Only horizontal seismic action
1.3
0.0
Only vertical seismic action
0.0
1.3
Both horizontal and vertical seismic action (mainly based on horizontal seismic action)
1.3
0.5
Both horizontal and vertical seismic action (mainly based on vertical seismic action)
0.5
1.3
5.4.2
The checking seismic resistance of cross-section of structural components shall be made
using the following design expression: S ≤ R/γRE Where
(5.4.2)
γRE ——Seismic adjusting coefficient for load-bearing capacity of the structural
component, which shall be determined according to Table 5.4.2 except having another requirements; R ——Design value of load-bearing capacity of the structural component. Table 5.4.2 Material
Seismic Adjusting Coefficient of Load-bearing Capacity
Type of structural component
Stress type
Column, beam, brace, panel, connecting bolt, weld j oint Steel
γRE
0.75 Stable strength
Colum, brace
0.80
Seismic wall with tie-columns or core-columns at both ends other
Shear
0.90
seismic wall
Shear
1.0
Beam
Bending
0.75
Columns with axial force ratio <0.15
Eccentric compression
0.75
Columns with axial force ratio ≥0.15
Eccentric compression
0.80
Seismic wall
Eccentric compression
0.85
All types of component
Shear, eccentric tension
0.85
Masonry
Concrete
5.4.3
When vertical seismic action is only considered, the seismic adjusting coefficient shall be
taken as 1.0 for all structural components. 5.5 5.5.1
Seismic Check for Deformation
Seismic deformation checks shall be made for all types of structures as per listed in Table 5.5.1,
and the maximum elastic storey drift shall meet the requirements of the following formula:
Δue ≤ [θ e ]h Where
(5.5.1)
Δue ——Elastic storey drift caused by the standard value of the Frequently Earthquake 38
action. The storey drift may be computed as the largest difference of the horizontal displacements along any of the edges of the structure at the top and bottom of the storey under consideration, unless the structure having predominate flexural deformation. When calculating, all of partial coefficients of various actions shall be taken as 1.0, and elastic rigidity may be used for reinforced concrete components (section); [θ e]——Limit value of elastic storey drift rotation which should be taken in accordance with Table 5.5.1; h ——Height of the calculated storey. Table 5.5.1
5.5.2
Limit Value of Elastic Storey Drift
Type of structures
[θ e]
Reinforcement concrete frame
1/550
Reinforcement concrete frame-seismic wall, slab-column-seismic wall, frame-core-tube
1/800
Reinforcement concrete seismic wall, tube-in-tube
1/1000
Reinforcement concrete frame-supporting storey of structure
1/1000
Multi-storey and tall steel structures
1/300
Elasto-plastic deformation check for the weak storeys (or locations) of the structure under the
rare earthquake shall meet the following requirements: 1
Elasto-plastic deformation check shall be done for the following structures: 1)
Bent-frames of single-storey reinforced concrete column factory with higher columns and larger spans for Intensity 8 with Site-category III and IV, or for Intensity 9;
2)
Reinforced concrete frame structures for Intensity 7~9, when the yield strength coefficient of the storey is less than 0.5;
3)
Structure with height greater than 150m;
4)
Reinforcement concrete structures and Steel structures, which assigned to Precautionary Category B for Intensity 9 and Precautionary Category A;
5) 2
Structures adopting seismic-isolation and energy dissipating designs.
Elasto-plastic deformation check should be done for the following structures: 1)
Tall building structures which height within the scope of as per listed in Table 5.1.2-1 and having also the vertical irregular types as per listed in Table 3.4.2-2;
2)
Reinforcement concrete and steel structures assigned Precautionary Category B for Intensity 7 with Site-category III and IV, or Intensity 8;
3)
Slab-column-seismic wall and masonry buildings with bottom-frame;
4)
Tall steel structures with height not greater than 150m.
5)
Irregular underground structure and underground space complex.
Note: The yielding strength coefficient of a storey is the ratio between t he shear bearing capacity (calculated according to the actual reinforcement and material strength standard value of RC components) and the elastic seismic shear force based on the standard
39
action under Rare Earthquake. For the bent-frame column, it refers to the ratio between the front section bending capacity (calculated according to the actual reinforcement, material strength standard value and axial force) and elastic seismic moment based on the standard action under rare earthquake.
Elasto-plastic deformation of a weak storey (or location) of a structure under the rare
5.5.3
earthquake may be determined according to the following methods: For framed structures that do not exceed 12 storeys and with no abrupt change of storey
1
rigidity and single-storey factory buildings with reinforced concrete column, the simplified method in Article 5.5.4 of this code may be used; For structures except those in Item 1 of this article, the static elasto-plastic analysis method
2
and the time-historey analysis method may be used; Regular structures may adopt bending shear model or planar line-components system model,
3
irregular structures as per listed in Section 3.4 of this code shall adopt spacious structure models. 5.5.4
The simplified calculation method for elasto-plastic storey drift in the weak storey (or location)
of a structure should meet the following requirements: 1
The weak storey (or location) may be identified as follows: 1)
For structures with a uniform distribution of storey yield strength coefficient a-long the height of the structure, the bottom storey of the building may be identified as the weak storey;
2)
For structures with non-uniform distribution of storey yield strength coefficient along the height of the structure, the storey (location) with minimum/smaller storey yield strength coefficient may be identified as the weak storey. However, in general, no more than two or three storeys (locations) may be identified as weak storeys;
3)
For single-storey factory buildings, the weak location is at the upper portion of the columns.
2
The elasto-plastic storey drift may be calculated according to the following formulae: Δu p=η pΔue
(5.5.4-1)
Or
Δu p= μΔuy=
Where
η p ξ y
Δu y
(5.5.4-2)
Δu p ——Elasto-plastic storey drift; Δuy ——Yield storey drift; u ——Storey ductility factor; Δue ——Elastic storey drift under the rare earthquake; ηq ——Amplifying coefficient for elasto-plastic storey drift. When the yield strength coefficient of the weak storey (location) is not less than 0.8 of the average value of coefficients of the neighboring storeys (location), it may be taken according to 40
Table 5.5.4. When the yield strength coefficient is not more than 0.5 of the abovementioned average value, it may be taken the corresponding values in the table multiplied by 1.5. When the yield strength coefficient is between the above two cases, it may be determined by interpolation method; ξ y ——Yield strength coefficient of storey. Table 5.5.4
Amplifying Coefficient for Elasto-plastic Storey Drift ξ y
Type of structure
Total storeys or location n 0.5
0.4
0.3
2~4
1.30
1.40
1.60
5~7
1.50
1.65
1.80
8~12
1.80
2.00
2.20
Upper portion of column
1.30
1.60
2.00
Multi-storey frame structure with uniform elevation Single-storey factory building
The elasto-plastic storey drift in the weak storeys (locations) of a structure shall meet the
5.5.5
requirements of the following formula: Δu p=≤[θ p]h Where
(5.5.5)
[θ p]——Limit value of elasto-plastic storey drift rotation, which can be taken according to Table 5.5.5. For reinforcement concrete frame structures, the values may be increased. Such as, it may be increased by 10% where axial-force-ratio is less than 0.40, it may be increased by 20% where the stirrup standard value along the full height of the column is 30% greater than the provisions in Table 6.3.9. But its total increase shall not be greater than 25%; h ——Height of the weak storey (location) or the height of the upper portion of column in single-storey factory building. Table 5.5.5
Limit Values for Elasto-plastic Storey Drift
Type of structures
[θ p]
Bent-frame of single-storey factory building with reinforced concrete columns
1/30
Reinforcement concrete frame
1/50
Frame-seismic wall of brick building with bottom-frame
1/100
Reinforcement concrete frame-seismic wall, slab-column-seismic wall, frame-core-tube
1/100
Reinforcement concrete seismic wall, tube-in-tube
1/120
Multi-storey and tall steel structures
1/50
41
6
Multi-storey and Tall Reinforcement Concrete Buildings 6.1
General Requirements
The provisions of this chapter shall be applied to seismic design of the structural type and
6.1.1
maximum height of cast-in-situ reinforced concrete buildings stipulated in Table 6.1.1. For structures assigned to irregular plan and elevation, the applicable maximum height shall be reduced appropriately. Note: The “seismic wall” inhere refers to reinforced concrete “shear-seismic wall” in lateral force resisting system of structure, excluding the concrete seismic wall only bearing gravity load.
Table 6.1.1
Applicable Maximum Height for Cast-in-situ Reinforced Concrete Buildings (m) Intensity
Type of structures 6
7
8 (0.2g)
8 (0.3g)
9
Frame
60
50
40
35
24
Frame-seismic wall
130
120
100
80
50
Seismic wall
140
120
100
80
60
Frame-support-seismic wall
120
100
80
50
No applicable
Frame-core-tube
150
130
100
90
100
70
Tube-in-tube
180
150
120
100
120
80
80
70
55
40
Tube Slab-column-seismic wall Note: 1
No applicable
The height of building refers to the height from the outdoor ground level to the main roof level of a building (which
locations exceeding roof level are not included); 2
Frame-core-tube structure refers to the structure composed of the perimeter frames and the core tubes;
3
Partial frame-support seismic structural wall refers to the frame-support layer structure
on the first storey or two storeys
on bottom, excluding individual frame-support seismic wall; 4
The frames stated in the table exclude special-shaped column frames;
5
Slab column-seismic structural wall refers to lateral resistant structure consisted of slab column, frames and seismic structural wall;
6
The applicable maximum height of Category B building may be determined according to the seismic precautionary Intensity in local region;
7
As for those buildings whose heights are greater than the ones in the table, special study and demonstration shall be made and effective reinforcement measures shall be taken.
6.1.2
For the seismic design of reinforced concrete buildings, different seismic measure Grade
shall be adopted according to the Fortification intensity, the Intensity, the structural type, the building height and its precautionary category, and shall satisfy the corresponding requirements of the calculation and design details. The measure Grade of buildings assigned to precautionary Category C shall be determined in accordance with the Table 6.1.2. 6.1.3
The determination for the seismic measure grads of reinforced concrete buildings shall also
meet the following requirements: 1
For frame-seismic wall subjected to the fundamental mode seismic action, when the seismic 42
overturning moment distributed to frame parts is more than 50% of the total seismic overturning moment of the structure, the measure Grade of frame parts for such structure shall be determined as that of the framed structures. Note: Bottom storey refers to the storey locating the fixing end calculated.
Table 6.1.2
Grade of Cast-in-situ Reinforced Concrete Structures Fortification Intensity
Type of structures 6
Frame structure
8
9
Height (m)
≤24
>24
≤24
>24
≤24
>24
≤24
Frame
4th
3rd
3rd
2nd
2nd
1st
1st
Large-span frame
Frame-seismic wall
7
3rd
2nd
1st
1st
Height (m)
≤60
>60
≤24
25~60
>60
≤24
25~60
>60
≤24
25~50
Frame
4th
3rd
4th
3rd
2nd
3rd
2nd
1st
2nd
1st
Seismic wall
3rd
3rd
2nd
2nd
1st
1st
Height (m)
≤80
>80
≤24
25~80
>80
≤24
25~80
>80
≤24
25~60
Seismic wall
4th
3rd
4th
3rd
2nd
3rd
2nd
1st
2nd
1st
Height (m)
≤80
>80
≤24
25~80
>80
≤24
25~80
Seismic wall
Frame-support
Seismic
Common part
4th
3rd
4th
3rd
2nd
3rd
2nd
seismic wall
wall
Reinforced part
3rd
2nd
3rd
2nd
1st
2nd
1st
Frames in brace storey
2nd
2nd
1st
Frame-core-tube
Fames
3rd
2nd
1st
1st
structure
Core-tube
2nd
2nd
1st
1st
Tube-in-tube
Exterior tube
3rd
2nd
1st
1st
structure
Interior tube
3rd
2nd
1st
1st
Height (m)
≤35
>35
≤35
>35
Frame, column
3rd
2nd
2nd
2nd
Seismic wall
2nd
2nd
2nd
1st
1st
≤35
>35
Slab-column-seismic 1st
wall Note: 1
2nd
1st
On Site-category I, the Grades of design details shall be permitted adopting according to reducing one Intensity degree which list in this t able unless Intensity 6, but the requirements for calculation shall not be reduced.
2
When the height of building is close to or equal to the height dividing line, the measure Grade shall be permitted adjusted appropriately in consideration of the degree of the building irregularity, the site and subsoil conditions;
3
Large-span frame refers to ones with span not less than 18m.
4
When the frames-core tube structure which the height is less than or equal to 60m is designed according to the requirements of frames-seismic structural wall, its seismic Grade shall be determined according to the requirements of the frames-seismic structural wall stated in the table.
2
When the podium is connected with the main building, the measure grads shall be determined
with the podium itself and shall not be lower than that of the main building. And design details of the main building shall be strengthened appropriately at the level of the top of podium and adjacent upper and lower level of that. When the main building and the podium are s eparated, the measure grads shall be determined according to the provision of the podium. 3
When the top-slab of the basement is used as the fixing location in the structural system
analysis, the measure Grade of the first storey underground shall be the same as the structural system. And the measure Grade of other storeys lower than first storey underground may be reduced storey by 43
storey, but it shall not be lower than the Grade 4. For parts of the basement without corresponding structural system, the measure Grade may be taken as Grade 3 or 4. 4
When the measure Grades of buildings assigned to Precautionary Category A and B, is raised
by a Grade as required, and the height of a building exceeds the height listed in Table 6.1.2, the effective seismic measures which higher than that of Grade 1 shall be taken. Note: The “measure Grade 1, 2, 3 and 4” hereinafter refer to “Grade 1, 2, 3, and 4” respectively.
6.1.4
When seismic joints are necessary of reinforced concrete buildings, that shall meet the
following requirements: 1
The width of the seismic joint shall meet the following requirements: 1)
For framed building structures (including framed structure arranged with a few of seismic structural wall), when the building height is not more than 15m, a width no less than 100mm may be used. And when the framed building height is more than 15m, then for the Intensity 6, 7, 8 and 9, the width shall be added by 20mm for every 5m, 4m, 3m and 2m increase in height respectively;
2)
For Frame-seismic wall building structures, this width shall not be less than 70% of the values as provision in Item 1); for seismic wall building structure, this width shall not be less than 50% of the values as provision in Item 1); besides, neither shall be smaller than 100mm;
3)
When the structural systems at the two sides of the seismic joint are different, such width shall be determined according to the structural system needed wider and the lower building height.
2
For Intensity 8 and 9, when the total height, rigidity or storey height of frame structures at the
two sides of the seismic joint are significantly different, the hoops of the frame column on both sides of the aseismic joint shall be thicken densed along the house at total height, and at least two compact resisting seismic wall perpendicular to aseismic joint may be arranged on the both sides of the joint along the house at total height as required. The arrangement of the compact resisting seismic wall should avoid incleasing twisting effect, the length hereof may not be larger than 1/2 the storey height, and the seismic Grade is same to the one of the framed structure; the internal force of the frame component shall be adopted according to the unfavorable situation with compact resisting seismic wall or without compact resisting seismic wall. 6.1.5
For frame or frame-seismic wall, its frames or seismic wall shall be arranged in two orthogonal
directions. The centerlines of beam-to-column or those of the column-to-seismic wall should coincide with each other, and if the eccentricity between the centerlines of beam-to-column or column-toseismic wall is greater than 1/4 of the column width, the influence of eccentricity shall be considered. Single span framed structure shall not be adopted for Category A and B buildings and Category C building which the height is larger than 24 m; single span framed structure should not be used for the Category C building which the height is not larger than 24m. 6.1.6
For frame-seismic wall and slab-column-seismic wall, the aspect ratio of the diaphragm,
which there are no large openings between two adjacent-seismic wall, should not exceed those set out in Table 6.1.6. If the aspect ratio is greater than those in Table 6.1.6, the influence of in-plane deformation of the diaphragm shall be considered. 44
6.1.7
When precast floor or roof components are used in frame-seismic wall, it shall be satisfied that
integrality of diaphragms and reliable connection between diaphragm and seismic wall; when cast-insitu top surface with reinforcement is adopted for fabricated complete floors and roofs, the thickness shall not be less than 50mm. Table 6.1.6
Aspect Ratio of the Diaphragm Between Two Adjacent-seismic wall Fortification Intensity
Type of floors and roofs 6
7
8
9
Cast-in-situ or lapped floors and roofs
4
4
3
2
Fabricated complete floors and roofs
3
3
2
Should not be adopted
Cast-in-situ floors and roofs with slab-column-seismic structural wall
3
3
2
—
Cast-in-situ or lapped floors and roofs with frame-support-storey
2.5
2.5
2
—
Frame-seismic structural wall
6.1.8
Installation of seismic wall in frame-seismic wall and slab-column-seismic wall should meet
the following requirements: 1
The seismic wall should be built through the overall height of the building.
2
The seismic wall should be built in staircase, however, large torsion afftec should be caused.
3
The both ends (excluding both sides of the opening) of the seismic wall should be connected
with end column or the seismic wall along other direction. 4
For long house (building), the longitudinal seismic wall with great rigidity should not be
arranged end bay; 5
The openings of the seismic wall should be aligned from the upper to the lower part; the
distance from the edge of the opening to the end column should not be less than 300mm. 6.1.9
Installation of seismic wall in seismic wall and frame-support-seismic wall shall meet the
following requirements: 1
The both ends (excluding both sides of the opening) of the seismic wall should be connected
with end column or the seismic wall along other direction; the both ends (excluding both sides of the opening) of the Frame-seismic wall shall be connected with end column or the seismic wall along other direction 2
A relatively long seismic wall should be divided uniformly into several seismic wall-segments
by installing of coupling beams that the span-to-depth ratio should greater than 6, and the heightto-width ratio of seismic wall-segments shall be not less than 3. 3
The length of seismic wall along overall height of a structure should not be cutout. The
relatively large openings of the seismic wall and the openings of bottom of seismic wall for Grade 1 or Grade 2, the openings should be aligned from the upper to the lower part. 4
For frame-support-seismic wall with rectangular plan, rigidity of frame-support storey shall
be not less than 50% of the rigidity of the adjacent upper first storey. The spacing of the seismic wall continuous to the ground shall not be larger than 24m, and the plan arrangement of lateral-forceresisting components of frame-support storey should also be symmetric and should be installed the tubes. The seismic overtuurning moment absorbed by the bottom frames shall not be greater than 50% the total seismic overtuurning moment of the structure. 45
6.1.10
The range of bottom reinforced part of seismic wall shall meet the following requirements:
1
The height of the bottom reinforced part shall be counted form the basement top plate.
2
For the frame-support-seismic structural wall, the height of the strengthening portion at the
bottom of seismic wall may be taken as the greater of the height of the two storeys above the frame-support storey and 1/10 of the total seismic wall height. For the seismic structural wall of other structures, when the house height is larger than 24m, the height of bottom reinforced part may be the larger one of 1/10 the total height of two bottom storeys and the seismic wall; when the house height is not larger than 24m, the height of the bottom reinforced part may be the one of a bottom storey. 3
When the structural calculation fixing end is located on the soleplate of underground storey
base or under it, the bottom reinforced part shall be extended under to the calculated partial fixing end. 6.1.11
In one of the following cases for framed structure, foundation tie beams should be installed
along both principal axial directions: 1
Frames assigned to Grade 1 or to Grade 2 with Site-category IV;
2
The representative values of gravity load on each column footing are differing greatly;
3
The buried depths of foundations or their relative difference are great;
4
In the range of the main bearing stratum of the subsoil, that exist weak cohesive soil layers,
layers liable to liquefaction, and seriously heterogeneous layers; 5 6.1.12
Connection between the one and other pile caps. The foundations of seismic wall in frame-seismic structural wall slab-column-seismic structural
wall and of seismic wall which continuing to ground in the frame-support-seismic wall shall have excellent integrality and anti-rotational capability. 6.1.13
If the podium is connected with the main building and adopted together the natural base,
besides satisfying the requirements of the provisions in Article 4.2.4 of this code, zero stress zones should not be occurred in the foundation bottom face of the main building under seismic action. 6.1.14
When the top slab of basement is used as the fixing location of the upper side structure, it
shall meet the following requirements: 1
The opening of large holes on this basement shall be avoided, at the same time, the top slab
with the scope of the ground structure corresponding to the basement shall adopt cast-in-situ structure and and the ones outside above scope should adopt cast-in-situ structure. The thickness of the slab should not be less than 180mm, the concrete strength should not be less than C30; the double layer and two way reinforcements shall be arranged, moreover, the ratio of reinforcement shall not be less than 0.25% 2
The lateral rigidity of the overground storey of the structure should not larger 0.5 times of the
lateral rigidity of the underground storey within the relevant range; the seismic structural wall connected to the top plate of the basement should be arranged around the basement periphery. 3
Besides meeting the seismic calculation requirements, the beam-column joint of basement top
plate corresponding to the overground frame column shall meet one of the following requirements: 1)
The longitudinal reinforcement on each side of column section on the first underground 46
storey shall not be large than 1.1 times of the longitudinal reinforcement corresponding to the first overground storey, and the seismic bent bearing capacity sum of the column upper end and joint beam end (right and left) shall not be larger than 1.3 times of the column lower end on the first overground storey. 2)
When the rigidity of the beam for the first underground storey is larger, the longitudinal reinforcement area of column section on both side shall be larger than 1.1 times of the longitudinal reinforcement of the column corresponding to the first overground storey; and the longitudinal reinforcement of the beam end top surface bottom surface shall all larger 10% than the calculated value.
4
The longitudinal reinforcement sectional area of the boundary structure on the extremity of
seismic wall on the first underground storey shall not be less than the one of the wall extremity corresponding to the first overground storey. 6.1.15
The staircase shall meet the requirements:
1
Cast-in-situ reinforced concrete stairs should be adopted.
2
As for framed structure, the layout of staircase shall not result in especial irregularity of the
structural plan; when the stairway components are casted with the major structure, the influence of the stairway components on earthquake action and effect shall be considered, and the checking calculation for stairway component seismic bearing capacity shall be conducted; the structure measure should be adopted to reduce the stairway component influence on the major structure rigidity. 3
The filler wall and column on the both sides of the staircase shall be strengthened in tie.
6.1.16
The filler wall for frames shall meet the requirements of Chapter 13.
6.1.17
The seismic design of high strength concrete structures shall meet the requirements in
Appendix B of this code. 6.1.18
The seismic design of prestressed concrete structures shall meet the requirements in Appendix
C of this code. 6.2 6.2.1
Essentials in Calculation
The design values of seismic effects of reinforced concrete structural components shall be
adjusted in accordance with the provisions in this section, and the storey drift shall meet the requirements in Section 5.5 of this code. If not specified in this chapter and related appendixes, the checking of components shall be made in accordance with the current codes for relevant structural design, but design value of the non-seismic bearing capacities of components shall be divided by the seismic adjusting factors provided in this code. 6.2.2
At the faces of each joint of the beam-column for assigned to Grade 1, 2, 3 and 4, the
combinatory moment design value of the column shall meet the requirements of the following formulae; except the joints of column in top storey or with axial-force-ratio less than 0.15 and of the supporting-columns of discontinuous seismic wall:
∑ M c = η ∑ M b
(6.2.2-1)
47
Grade 1 framed-structures or Grade 1 frame at Intensity 9 may not meet above requirements, but they shall comply with:
∑ M c = 1.2 ∑ M bua Where
(6.2.2-2)
Σ M c ——Sum of combinatory moment design values in clockwise or counterclockwise direction of column at the faces of the joint; in general case, the moments at the upper and lower faces of the joint may be distributed by elastic analysis; Σ M b ——Sum of combinatory moment design values in counter-clockwise or clockwise direction of beam at the faces of the joint. For Grade 1 frame, the moments at the lift and right faces of the joint are negative together, that of the smaller absolute value may be taken as 0; Σ M bua ——Sum of moments in counter-clockwise or clockwise direction at the faces of the joint corresponding to actual seismic bending capacity of normal cross section of beams framing into that joint, which may be determined by actual reinforcement area (including bearing reinforcement for beam and related slab reinforcement) and standard value of the material strength; ηc ——Enhancement coefficient of the moment of column end, for frames structures, taken as 1.7, 1.5, 1.3 and 1.2 respectivley for Grade 1, 2, 3 and 4; for other stuctures, taken as 1.4 for Grade 1, taken as 1.2 for Grade 2, and taken as 1.1 for Grade 3 and 4.
When the zero-moment-point is not in the range of a storey height of the column, the combinatory moment design value of the column may be multiplied by the above enhancement coefficient. 6.2.3
At the first storey of frames assigned to Grade 1, 2, 3 and 4, the combinatory moment design
values of the lower end of columns shall be multiplied by an enhancement coefficient of 1.7, 1.5, 1.3 and 1.2 respectively. The longitudinal reinforcement of the column at the first storey shall be arranged according to unfavorable conditions in its upper and lower ends. 6.2.4
For frame beams and coupling beams with span-to-, the shear force design values of the beam
ends shall be adjusted according to the following formulae:
V = η vb + ( M bl + M br ) / l n + V Gb
(6.2.4-1)
Grade 1 framed-structures or Grade 1 fame at Intensity 9 may not meet the above requirments, buy they shall also comply with: l r V = 1.1( M bua + M bua ) / l n + V Gb
Where
(6.2.4-2)
V ——Combinatory shear force design value of the beam-ends; l n ——Clear span of the beam; V Gb ——Shear force design value of the beam end obtained in the analysis based on simply supported beams, which subjected to the representative value of gravity load (for the Intensity 9, it shall include also the standard value of vertical seismic action for tall buildings); 48
M bl , M br ——The combinatory bending moment design values in clockwise or counterclockwise direction of the beam end assigned to right and left respectively. For Grade 1 frame, the bending moments at the right and left end of beams are negative together, which of the smaller absolute value may be taken as 0; l r , M bua ——The bending moments in clockwise or counter-clockwise direction corresponding to M bu
actual seismic bending capacity of normal cross section of the beam assigned to left and right ends respectively, that may be determined by actual reinforcement amount (counted into compression reinforcement and related slab reinforcement) and standard value of the material strength; ηvb ——The enhancement coefficient of shear force for the beam end, taken as 1.3 for Grade 1, taken as 1.2 for Grade 2, and taken as 1.1 for Grade 3. 6.2.5
For the frame column and Supporting-column of discontinuous seismic wall assigned to Grade
1, 2, 3 and 4, the combinatory shear force design values of the columns shall be adjusted according to the following formula:
V = η vb ( M bc + M ct ) / H n
(6.2.5-1)
Grade 1 framed-structures or Grade 1 frame at Intensity 9 may not meet above requirements, bu they shall also comply with: t V = 1.2( M bcua + M cua ) / H n
Where
(6.2.5-2)
V ——Combinatory shear force design value of cross-sections at the column ends; for the frame-support-column, which shall also meet the requirements of the provisions in Article 6.2.10 of this code; H n ——Clear height of the column;
M bc , M ct ——Combinatory moments design value in clockwise or counter-clockwise direction of the column assigned to upper and lower end respectively, which shall meet the requirements of the provisions in Article 6.2.2 and 6.2.3 of this code. For the frame-support-column, that shall also meet the requirements of the provisions in Article 6.2.10 of this code; t ——Bending moment values in the clockwise and counter-clockwise directions M bcua , M cua
corresponds to the normal cross section seismic bending capacity of the eccentric compression column assigned to upper and lower ends respectively; and they shall be determined by the actual reinforcement amount, the material strength standard value and the axial compressive force etc.; ηvc ——Enhancement coefficient of the column shear force, for frames structures, taken as 1.5, 1.3, 1.2 and 1.1 respectivley for Grade 1, 2, 3 and 4; for other stuctures, taken as 1.4 for Grade 1, taken as 1.2 for Grade 2, and taken as 1.1 for Grade 3 and 4. 6.2.6
For corner columns of frames assigned to Grade 1, 2, 3 and 4, the combinatory bending 49
moment design values of the columns, adjusted rate according to Article 6.2.2,
6.2.3, 6.2.5 and
6.2.10 of this code, shall also be multiplied by the enhancement coefficient 1.10. The combinatory internal force design value of all limb seismic wall section of the seismic
6.2.7
wall shall be determined according to the following provisions: In strengthened portion at the bottom and its upper storey of the seismic wall assigned to
1
Grade 1, the combinatory moment design value of the seismic wall shall be multiplied by the enhancement coefficient, which may be taken as 1.2. For the frame-support-seismic wall, the small eccentric tensioning should not occur on the
2
seismic wall continued to ground. In the double-limb coupling seismic wall, the small eccentric tensioning should not occur on
3
limb- seismic wall; when that is occur on anyone limb-seismic wall, the combinatory shear force design value and moment design value of the another limb-seismic wall shall be multiplied by an enhancement coefficient 1.25. For the strengthening portion of the bottoms of the seismic wall assigned to Grade 1, 2, and 3 ,
6.2.8
the combinatory shear force design value of the seismic wall shall be adjusted according to the following formula:
V = η vwV w
(6.2.8-1)
The Grade 1 ones at Intensity 9 may not meet above requiremnts, but it shall also comply with:
M V = 1.1 wua V w M w Where
(6.2.8-2)
V ——The combinatory shear force design value of the seismic wall at the strengthening portion of the bottom; V w ——Calculated combinatory shear force value of the seismic wall at the strengthening portion of the bottom;
M wua ——The moment corresponding to the actual seismic bending capacity of the bottom face of the seismic wall, which shall be determined by the actual reinforcement amount, the material strength standard value and the axial compressive force. When the flange exists, the longitudinal bars within one thickness of flange at the two sides of web shall be taken into account; M w ——Combinatory moment design value of the bottom face of the seismic wall; ηvw ——Shear force enhancement coefficient of the seismic wall, taken as 1.6 for Grade 1, taken as 1.4 for Grade 2, and taken as 1.2 for Grade 3. 6.2.9
The combinatory shear force design value of cross-sections at the ends of beams, columns,
seismic wall and its coupling beams shall comply with the following requirements: For beams and coupling beams with span-to-depth ratio greater than 2.5 and columns and seismic wall with shear-span-ratio greater than 2: 50
1
V ≤
γ RE
(0.20 f cbh0 )
(6.2.9-1)
For coupling beams with span-to-depth ratio not greater than 2.5, and the columns and seismic wall with shear-span-ratio not greater than 2, such as the supporting-columns and supporting-girders of discontinuous seismic wall as well as the strengthened portion at bottom of the seismic wall continued to ground in the frame-support-seismic wall:
V ≤
1 γ RE
(0.15 f cbh0 )
(6.2.9-2)
The shear-span-ratio shall be calculated according to the following formula:
λ = M c /(V c h0 ) Where
(6.2.9-3)
λ ——Shear-span-ratio; which shall be taken the greater value among the calculation values ( M c) of the combined bending moment of column or seismic wall end cross-section, the calculation values (V c) of combined shear forces of corresponding cross-section, and the effective height (h0) of the cross-section; for the framed column which the contraflexure point is located on the middle of the column may be calculated according to the ratio of the net column height to the 2 times the column sectional area; V ——Combinatory shear force design value of the beam ends, column ends, or seismic wall section, that shall be determined in accordance with the provision of the Articles 6.2.4, 6.2.5, 6.2.6, 6.2.8 and 6.2.10 of this code; f c ——Design value of axial compressive strength of concrete; b ——Cross-sectional width of the beam, column or shear seismic wall, and it may be calculated by using the equal square section for the circular section; h0 ——Effective depth of component or effective height of cross-section, for shear seismic wall, it may be taken as the lateral dimension.
6.2.10
The supporting-columns of discontinuous seismic wall of the frame-support-seismic wall
shall also satisfy the following requirements; 1
The minimum seismic shear forces distributed to the Supporting-column shall comply with as
follows; when the number of Supporting-columns is more than 10, the sum of seismic shear force of the Supporting-columns shall not be less than 20% of the seismic shear force of the same storey. When the number of Supporting-columns is less than 10, the seismic shear force of each Supportingcolumn shall not be less than 2% of the seismic force of the same storey. 2
For Supporting-columns of discontinuous seismic wall assigned to Grade 1 and 2, the
additional axial force of columns produced by the seismic action shall be multiplied by the enhancement coefficients 1.5 and 1.2 respectively; but when calculating the axial-force-ratio, the additional axial force may not be multiplied by such enhancement coefficients. 3
For the upper end of the top storey and lower end of first storey of the Supporting-columns of 51
discontinuous seismic wall assigned to Grade 1 and 2, the combinatory moment design values of columns shall be multiplied by the enhancement coefficients 1.5 and 1.25 respectively. And the middle joints of the Supporting-column shall satisfy the requirements in Article 6.2.2 of this code. 4
The centerline of the supporting-girders of discontinuous seismic wall should be coincided
with the centerline of cross section of the Supporting-columns of discontinuous seismic wall. 6.2.11
The strengthening portion at bottom of the seismic wall continued to ground of the
frame-support- seismic wall assigned to Grade 1 shall also satisfy the following requirements: 1
When the ties with diameter not less than 8mm and spacing not larger than 400mm are
arranged between two rows of reinforcement beyond the boundary elements, the checking calculation for the shear bearing capacity of seismic structural wall may be counted with the shear bearing action of the concrete. 2
When building with the bottom of the limb-seismic wall has eccentric tensions, the additive
anti- sliding diagonal bars should be placed at intersection surface of the limb-seismic wall and the foundation. The tension resisted by the anti-sliding diagonal bars may be taken as 30% of the shear force design value at the intersection surface. 6.2.12
The diaphragms of Transference-storey of frame-support-seismic wall shall meet the requirements
of Section E.1 in Appendix E of this code. 6.2.13
Seismic calculation for the reinforced concrete structures shall also meet the following
requirements: 1
For frame-seismic wall having even distribution of lateral rigidity along vertical configuration,
the seismic shear force resisted by the frame-part of any storey shall not be less than which the 20% of the total seismic action of the structure or 1.5 times of maximum seismic shear force in all storeys in the frame-part according to structural analysi s, whichever smaller. 2
The rigidity of the coupling-beam of the seismic-seismic wall may be reduced, which shall
not be less than 0.50. 3
When calculating the interior force and deformation of the seismic wall, the frame-support-
seismic wall, the frame-seismic wall, tube-in-tube structure, and slab-column-seismic wall, the interaction of the end wing seismic wall shall be considered for seismic structural wall. 4
As for the framed structure arranged with less seismic structural wall, the seismic shock shear
force of the frame part hereof should be the larger one of the calculated results of the framed structure model and frames - seismic wall structural model. 6.2.14
The seismic check for the frame nodes, which referred to the portion of structure common to
intersecting beams and columns, shall meet the following requirements: 1
The seismic capacity of nodes for frames assigned to Grade 1, 2 or 3 shall be checked; and
may not be checked for frames assigned to Grade and 4, but these shall meet the requirements of design details. 2
Method for checking of seismic capacity for the nodes of frame shall meet the requirements
in Appendix D of this code. 6.3
Details of Seismic Design for Framed Structures 52
Dimensions of cross-section of beams should meet the following requirements:
6.3.1 1
Width of beams should not be less than 200mm;
2
The depth-to-width ratio of beams should not be larger than 4;
3
Ratio of clear span to depth of beams should not be less than 4. The flat beam with the width is more than width of the column shall meet the following
6.3.2
requirements: Floors and roofs with flat beam shall be cast in-situ, the centerlines of the beams and columns
1
should be coincided, and the flat beam shall be arranged in double principal axial directions. The cross-sectional dimension of the flat beam shall comply with the following formulae; and the provisions controlling deflection and cracked width of beam in governed current codes shall also be satisfied:
Where
b b≤2bc
(6.3.2-1)
b b≤bc+h b
(6.3.2-2)
h b≤16d
(6.3.2-3)
bc ——Width of the column; for circular columns, that taken as 0.8 times of the diameter; b b, h b ——The width and depth of the beam respectively; d ——Diameter of longitudinal reinforcements in the column. Flat beam should not be used for Grade I frames.
2 6.3.3
Arrangement of reinforcement in beams shall meet the following requirements:
1
The height and effective height ratio of the concrete compressive region of beam end
counted into the compressive reinforcement, for Grade 1, shall not be greater than 0.25; for Grade 2 and 3, it shall not be greater than 0.35. 2
Except that determined in calculation, the longitudinal reinforcement ratio of the beam
end section bottom surface to the top surface, for Grade 1 shall be greater than or equal to 0.5; for Grade 2 and 3, shall not be lower than 0.3. 3
Length arranged densified hoops, maximum spacing and minimum diameter of hoops
at both ends of beam shall be taken in accordance with Table 6.3.3. When the reinforcement ratio of the tensile longitudinal bars at the beam end exceeds 2%, the minimum diameter of hoops in the Table shall be increased by 2mm. Table 6.3.3
Length of the Densified Regions, Maximum Spacing and Minimum Diameter of Hoops in a Beam Length arranged densified hoops (the
Maximum spacing of hoops (smallest
Minimum diameter of
greater value shall be taken) (mm)
value shall be taken) (mm)
hoops (mm)
1
2hb, 500
hb/4, 6d , 100
10
2
1.5hb, 500
hb/4, 8d , 100
8
3
1.5hb, 500
hb/4, 8d . 150
8
4
1.5hb, 500
hb/4, 8d , 150
6
Seismic Grade
Note: 1
d refers to the diameter of longitudinal bars; hb refers to the depth of the beam.
53
2
When the diameter of the hoop is larger than 12mm, the quantity is not less than 4 and the limb distance is not less than 150 mm, the maximum spacing of ones of Grade 1 and 2 may be raised properly, but it shall not be larger than 150mm.
Arrangement of the longitudinal reinforcements in beams shall also meet the following
6.3.4
requirements: 1
the reinforcement ratio of longitudinal reinforcement at beam end should not be larger than
2.5%. Continuously longitudinal reinforcements at the top-face and the bottom-face of beams shall be not less than 2ø14, and also not less than 1/4 of the greater amount of top or bottom longitudinal beam bars at both ends for frames assigned to Grade 1 or 2. And that shall be not less than 2ø12 for frames assigned to Grade 3 or 4; 2
Diameter of each longitudinal beam reinforcement, which extending through a mid-column-
beam joint for frames assigned to Grade 1, 2 or 3, shall not be larger than 1/20 of the sectional dimension parallel to the beam reinforcement for column with rectangular section. For circular columns, the diameter shall not be larger than 1/20 of the chord length of the column section where such beam reinforcement locates. As for the frames of other structural types, the diameter should neither be larger than 1/20 of the sectional dimension parallel to the beam reinforcement for column with rectangular section nor 1/20 of the chord length of the circular column section where such beam reinforcement locates. 3
The spacing of the hoop limbs in beam end densified area, for Grade 1, should not be larger
than the larger one of 200mm and 20 times the hoop diameter; for Grade 2 and 3, it should not be larger than the larger one of 250mm and 20 times of the hoop diameter; for Grade 4, it should not be larger than 300mm. Dimension of cross-section of columns should meet the following requirements:
6.3.5 1
The width and height, for Grade 4 and exceeding 2 storeys, should not be less than 300mm;
for Grade 1, 2 and 3, and exceeding 2 storeys, it should not be less than 400mm; the diameter of round column, for Grade 4 and exceeding 2 storeys, should not be less than 350mm; or Grade 1, 2 and 3, and exceeding 2 storeys, it should not be less than 450mm. 2
The shear span-to-depth ratio should be larger than 2.
3
The ratio of the longest cross-sectional dimension to the perpendicular dimension should not
be larger than 3. 6.3.6
Axial-force-ratio of the column should not exceed the limit values as shown in Table 6.3.6; for
tall building structures built on Site-category IV, this axial-force-ratio shall be reduced accordingly. Table 6.3.6
Limit Value for the Axial-force-ratio of Column Seismic Grade
Type of structure Frame structures
1
2
3
4
0.65
0.75
0.85
0.90
0.75
0.85
0.90
0.95
0.6
0.7
Frame-seismic wall, slab-column-seismic wall, frame-core-tube, tube-in-tube Frame-support seismic wall Note: 1
—
The axial-force-ratio refers to the ratio of the combinatory axial compressive force (including seismic effects) design value of column to the product of the column cross-sectional area and the concrete compressive strength design values. As for
54
structures, which may not be seismic checked, it may be taken as combinatory axial compressive force design value without seismic effects; 2
The limit values in the table are applicable to columns whose shear span-to-depth ratio is larger than 2 and the strength Grade of concrete are not higher than C60. For columns whose shear span-to-depth ratio is not larger than 2, the limit values of axial-force-ratio shall be reduced by 0.05; for columns with shear span-to-depth ratio less than 1.5, the limit value of Axial-force-ratio shall be studied especially and special details shall be taken;
3
The compound hoops are adopted along overall height of the column and the distances between the crossties or legs is not larger than 200mm, the spacing of hoops is not larger than 100mm and the diameter of hoop is not less than 12mm. The compound spiral hoops are adopted along overall height of the column, and the spiral spacing is not larger than 100mm, the distance between the crossties or legs is not larger than 200mm and the diameter of the hoops is not less than 12mm. The continuous compound rectangular spiral hoops are adopted along overall height of the column, the clear spiral distance is not larger than 80mm, the distance between the crossties or legs is not larger than 200mm and the diameter of spiral hoop is not less than 10mm; The limit values in the table may be increased 0.10 in following three cases, but that hoop characteristic factors of the three cases shall be determined according to Table 6.3.9 in the light of the enlarged Axial-force-ratios;
4
When the additive core-longitudinal-bars are arranged in the middle of the cross section of the column, that the total cross-sectional area of the additive longitudinal bars shall not be less than 0.8% of the cross s ection area of column, the limit values in the table may be increase 0.05. When these longitudinal reinforcements is adopted together with the hoops provided in Note 3, the limit values in the table may be increase 0.15, but the hoop characteristic factors may be determined in according with the provision of that the axial-force-ratio is increased by 0.10;
5
6.3.7
The Axial-force-ratio of columns shall not be grater than 1.05 in every case.
The arrangement of reinforcement in columns shall meet the following requirements;
1
Minimum total reinforcement ratio of longitudinal bars in columns shall be adopted as
shown in Table 6.3.7-1, and the total reinforcement ratio in each side shall not be less than 0.2%; for tall building structures built at Site-category IV, the values in the Table shall be increased by 0.1%. Table 6.3.7-1
Minimum Total Steel Ratios of Longitudinal Bars in Columns (%) Seismic Grade
Type 1
2
3
4
Central column and side column
0.9 (1.0)
0.7 (0.8)
0.6 (0.7)
0.5 (0.6)
Corner column and frame-support column
1.1
0.9
0.8
0.7
Note: 1 2
The values bracketed in the table are applicable to the columns in framed structure; When the standard value of reinforcement strength is lower than 400MPa, the values in table may be raised by 0.1; when the standard value of reinforcement strength is 400MP, the value shall raised by 0.05 accordingly.
3
2
When the concrete strength Grade is higher than 60, above values shall be raised by 0.1.
The hoops shall be densified in the provision regions; the spacing and diameter of such
hoops shall meet following requirements: 1)
In general, maximum spacing and minimum diameter of hoops shall be taken in accordance with Table 6.3.7-2.
2)
For Grade 1 frame column which the hoop diameter is larger than 12mm and the 55
hoop limb spacing is not larger than 150 mm and frames assigned to Grade 2, when the diameter of hoops is not less than 10mm and distance between crossties or legs of compound hoop not larger than 200mm, unless the column bottom, the maximum spacing of hoops shall permitted to adopt 150mm. For frames assigned to Grade 3, when the cross-sectional dimension of columns is not larger than 400mm, the minimum diameter of the hoop shall permitted to adopt 6mm. For frames assigned to Grade 4 with the shear span-to-depth ratio not larger than 2, the diameter of the hoops shall not be less than 8mm. Table 6.3.7-2
Maximum Spacing and Minimum Diameter for Hoops in the Column Hoop Densified Regions
Seismic Grade
Maximum spacing of hoops (smaller value shall be taken) (mm)
Minimum diameter of hoops (mm)
1
6d , 100
10
2
6d , 100
8
3
8d , 150 (in column bottom 100)
8
4
8d , 150 (in column bottom 100)
6 (in column foot 8)
Note: 1 2
3)
d refers to the minimum diameter of the longitudinal bar in the column; The column bottom refers to the fixing section of the low end of column on first storey.
For Supping-columns of discontinuous seismic wall and columns with the shear span-to- depth ratio is not larger than 2, spacing of hoops shall be not larger than 100mm.
6.3.8
Arrangement of longitudinal bars in the column shall also meet the following requirements:
1
They should be arranged symmetrically.
2
Spacing of longitudinal bars should not be larger than 200mm for columns that the cross-
sectional dimension is larger than 400mm. 3
The total reinforcement ratio of the colums shall not be larger than 5%; for the columns with
shear span-to-depth ratio not larger than 2 and assigned to Grade 1, the reinforcement ratio on each side should not larger than 1.2%. 4
When small eccentric tension occurs at the side column, the corner column and the end-
column of the seismic wall under the seismic action, the total cross-sectional area of longitudinal bars of such columns shall increase 25% of the calculated necessary value. 5
The banding joint for column longitudinal reinforcement shall be avoided from the hoop
densified area of the column end. 6.3.9 1
The regions of densified hoops in the column shall meet the following provisions: The hoop densed scope of the column shall be determined according to the following
requirements: 1)
For the all ends of the columns, the length from each joint face shall not be less than the largest of the depth of column at the joint face, 1/6 of the clear column height and 500mm;
2)
For column in the first storey, the length from fixed point of column shall not be less than 1/3 of the clear column height; 56
3)
The length shall also be taken from 500mm upper to 500mm lower of the rigid ground surface.
4)
For columns with Shear span-to-depth ratio not larger than 2, and columns with ratio of the clear column height to depth not larger than 4 which is caused by the filling seismic wall etc., shall be taken as the overall height of column.
The distance between the crossties or legs in the densified regions of hoops of columns
2
should not exceed 200mm for frames assigned to Grade 1, not exceed 250mm for Grade 2 or 3, and not exceed 300mm for Grade 4. The crossties or legs should be arranged in two directions for every other longitudinal bars for confinement; when the compound hoops are used, the crossties or legs should hooking together the longitudinal bar and the hoop. The volumetric ratio of spiral or hoop reinforcement in the densified regions of the column
3
shall comply with the following requirements: 1)
The volumetric ratio of spiral or hoop reinforcement in the densified regions of the column shall comply with the following formula:
ρ v ≥ λ v f c / f yv Where
(6.3.9)
ρv ——Volumetric ratio of spiral or hoop reinforcement in the densified regions of the column; which shall not be less than 0.8% for frames assigned to Grade 1, 0.6% for frames assigned to Grade 2, and 0.4% for frames assigned to Grade 3 and 4 respectively. When calculating the volumetric ratio for compound hoops, the volume in the overlapping parts shall be reduced by 0.80; f c ——Specified compressive strength design value of concrete; when the strength Grade is lower than C35, the calculation shall be done according to C35; f yv ——Specified tensile strength design value of hoop or tie reinforcement; λv ——The minimum hoop characteristic factors, which should be taken in accordance with Table 6.3.9. Table 6.3.9
Minimum Hoop Characteristic Factors Axial-force-ratio
Seismic Grade
Type of hoops Ordinary hoop, compound hoop
1
≤0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.05
0.10
0.11
0.13
0.15
0.17
0.20
0.23
—
—
0.08
0.09
0.11
0.13
0.15
0.18
0.21
—
—
0.08
0.09
0.11
0.13
0.15
0.17
0.19
0.22
0.24
0.06
0.07
0.09
0.11
0.13
0.15
0.17
0.20
0.22
0.06
0.07
0.09
0.11
0.13
0.15
0.17
0.20
0.22
0.05
0.06
0.07
0.09
0.11
0.13
0.15
0.18
0.20
Spiral hoop, compound or continuous compound rectangular spiral hoop Ordinary hoop, compound hoop
2
Spiral hoop, compound or continuous compound rectangular spiral hoop Ordinary hoop, compound hoop
3
Spiral hoop, compound or continuous compound rectangular spiral hoop
Note: Ordinary hoops refer to single rectangular hoops and circular hoops. Compound hoops refer to hoops formed by rectangular hoops and rhombic, polygonal, circular hoops or crossties. Compound spiral hoops refer to hoops formed by spiral hoop and
57
rectangular, rhombic, polygonal, circular hoops or crossties; continuous compound rectangular hoops refer to all of spiral hoops that are made of one steel bars;
2)
Supporting-columns should adopt compound spiral hoops or compound hoops, the minimum hoop characteristic factors shall increase 0.02 than the provisions in Table 6.3.9; and the volumetric ratio shall not be less than 1.5%.
3)
Columns with shear span-to-depth ratio not larger than 2 should adopt compound spiral hoops or compound hoops, its volumetric ratio shall not be less than 1.2%, and shall not be less than 1.5% for Intensity 9.
4
The arrangement of hoops for non-densified area of column hoops shall meet the following
requirements: 1)
The volumetric ratio of stirrups in the non-densified regions of hoop of the column should not be less than 50% of that in the densified regions.
2)
And also spacing of stirrups shall be not larger than 10 times of the longitudinal bras diameter for frames assigned to Grade 1 or 2 and 15 times for frames assigned to Grade 3 or 4 respectively.
6.3.10
The maximum spacing and minimum diameter of hoops at a node of the frame should
conform to the provision in Table 6.3.7. The hoop characteristic factors at the node of frames assigned Grade 1, 2 and 3 should not be less than 0.12, 0.10 and 0.08, and the hoop volumetric ratio should not be less than 0.6%, 0.5%, and 0.4% respectively. For columns with shear span-to-depth ratio not larger than 2, the hoop characteristic factors in the node of the frame should not be less than the greater of the upper and lower column ends of that node. 6.4 6.4.1
Details of Seismic Design for the Seismic Structures Seismic wall
The thickness of a seismic-seismic wall shall not be less than 160mm and/or 1/20 of the storey
height for structures assigned to Grade 1 or 2, and 140mm and/or 1/25 of the storey height for structures assigned to Grade 3 or 4. For the strengthening portion at the bottom of the seismic wall assigned to Grade 1 or 2, the thickness of seismic wall should not be less than 1/16 of the storey height; and 1/20 of the storey height where seismic wall without end-columns or flanges. The seismic wall thickness of bottom reinforced part, for Grade 1 and 2, shall not be less than 200 mm and the storey height or 1/16 the non-support part length; for Grade 3 and 4, it shall not be less than 160mm and the storey height or 1/20 the non-support part length; the seismic wall thickness of no-end column or wing seismic wall, for Grade 1 and 2, should not be less than the storey height or 1/12 the non-support part length; for Grade 3 and 4, it should not be less than the storey height or 1/16 the non-support part length. 6.4.2
The Axial-force-ratio of the strengthening portion at bottom of the seismic wall subjected to
the gravity load representing value should not larger than 0.4 for structures assigned to Grade 1 with Intensity 9, 0.5 for structures assigned to Grade 1 with Intensity 7 and 8, and 0.6 for structures assigned to Grade 2. Note: The wall limb axial force ratio refers to the ratio of the wall axle pressure design value to the product of the total sectional area of wall and the concrete axes compression strength design value.
58
6.4.3
The vertical and horizontal distributed web reinforcements in a seismic wall shall meet
the following requirements: 1
The critical steel ratio of vertical and lateral reinforcement for Grade 1, 2 and 3 seismic
wall shall not be less than 0.25; for Grade 4 seismic wall, the critical steel ratio of reinforcement shall not be less than 0.20%. Note: As for the Grade 4 seismic wall with height less than 24m and less shear pressure ratio, the critical steel ratio of the vertical distribution reinforcement hereof shall be 0.15%.
2
At the strengthening portion at the bottom of the seismic wall for frame-support-seismic
wall, the reinforcement ratio each way shall not be less than 0.3% 6.4.4
The vertical and horizontal distributed web reinforcements in a seismic wall shall meet the
following requirements: The spacing of the vertical and lateral reinforcement for seismic structural wall should not be
1
larger than 300mmm and the spacing of vertical and lateral reinforcement for the ground seismic structural wall bottom reinforced part of partial frame-support seismic structural wall should not be larger than 200mm. When the seismic structural wall thickness is larger than 140mm, the vertical and lateral
2
reinforcement shall be arranged in two rows, and the spacing between the tie wires for two rows of distribution reinforcement should not be larger than 600mm, and the diameter hereof shall not be less than 6mm. 3
The diameter of vertical and lateral reinforcement (bar) for seismic structural wall should not
be larger than 1/10 the seismic wall thickness and not less than 8mm; the vertical reinforcement diameter should not be less than 10mm. 6.4.5
The two ends and opening sides of the seismic wall shall be installed with boundary components,
and the boundary components include hidden column end, column and flange seismic wall and they shall meet the following requirements: As for seismic structural wall, structure boundary component may be arranged on both ends
1
of seismic wall limb when the axial force ratio of the base seismic wall limb bottom section is not larger than the ones of Grade 1, 2 and 3 seismic structural wall specified in Table 6.4.5-1 and Grade 4 seismic structural wall, and the range of structure boundary component may be adopted according to Figure 6.4.5-1. Besides meeting the requirements in bending bearing capacity, the structure boundary component reinforcement should meet the requirements of Table 6.4.5-2. Table 6.4.5-1
Maximum Axial-force-ratio of Seismic wall for Installing the Ordinary Boundary Elements
Seismic Grade or Intensity
Grade 1 with Intensity 9
Grade 1 with Intensity 7 and 8
Grade 2 and 3
Axial-force-ratio
0.1
0.2
0.3
Table 6.4.5-2 reinforcement requirements of aseismic wall boundary structures Bottom reinforced part
Other part
Seismic
Minimal longitudinal
Grade
reinforcement
Minimum
Maximum vertical
reinforcement
Minimum
Maximum vertical
(Larger one)
diameter (mm)
spacing (mm)
(adopting larger one)
diameter (mm)
spacing (mm)
Loops
Minimal longitudinal
Lacing wire
59
1
0.010 Ac, 6ø16
8
100
0.008 Ac, 6ø14
8
150
2
0.008 Ac, 6ø14
8
150
0.006 Ac, 6ø12
8
200
3
0.006 Ac, 6ø12
6
150
0.005 Ac, 4ø12
6
200
4
0.005 Ac, 4ø12
6
200
0.004 Ac, 4ø12
6
250
Note: 1 Ac Refers to the sectional area of boundary component; 2
As for lacing wire on other parts, the level spacing shall not be greater twice than the longitudinal tendon spacing; the hoops should be used at corner;
3
When the end column bear concentrated load, the longitudinal reinforcement, hoop diameter and spacing shall meet corresponding requirements.
Hidden column
Flankin column
End column
Figure 6.4.5-1 Range of structure boundary component for seismic structural wall
2
When the axial force ratio of the limb bottom section of base seismic wall is larger than the
one of Grade 1, 2 and 3 seismic structural wall specified in Table 6.4.5-1, and seismic structural wall with partial frame-support seismic structural wall, restraining boundary components shall be arranged on bottom reinforced part and adjacent upper storey, and structure boundary component may be arranged on other parts. The length along seismic wall limb, hoop standard value and hoop / longitudinal reinforcement of restraining boundary components should meet the requirements of Table 6.4.5-3 (Figure 6.4.5-2). Table 6.4.5-3: range and reinforcement requirements of restraining boundary components for seismic structural wall Grade 1 (Intensity 9)
Grade 1 (Intensity 8)
Grade 2 and 3
λ ≤ 0.2
λ >0.2
λ ≤ 0.3
λ >0.3
λ ≤ 0.4
λ >0.4
l c (hidden column)
0.20 hw
0.25 hw
0.15 hw
0.20 hw
0.15 hw
0.20 hw
l c (Flange seismic wall or end column)
0.15 hw
0.20 hw
0.10 hw
0.15 hw
0.10 hw
0.15 hw
λ v
0.12
0.20
0.12
0.20
0.12
0.20
Item
Longitudinal reinforcement (adopting larger value)
0.012 Ac , 8φ16
0.012 Ac , 8φ16
0.010 Ac , 6φ16
(6φ14 for Grade 3) Vertical spacing of Hoop or lacing wire
100mm
100mm
150mm
60
Notes: 1
When the length of the flange seismic wall for seismic structural wall is less than 3times the thickness or the side length of
the end column section is less than 2 times of the seismic wall thickness, it may be selected according to the condition of no flange seismic wall or end column;
2
l c
is the length along the seismic wall limb of the restraining boundary components; it is not less than the seismic wall thickness
and 400 mm; if flange seismic wall or end column is arranged, it shall not be less than the thickness of flange seismic wall or the depth of section of end column along the seismic wall limb plus 300mm;
3
λ v is the stirrup (hoop) arrangement standard value of restraining boundary components. The volume arrangement ratio is
calculated according to Formula (6.3.9) in this code. The sectional area of horizontal distribution reinforcement meeting the construction requirements and with the reliable anchoring at seismic wall end may be counted properly;
4
hw
5
λ
6
Ac
is the length of seismic structural wall limb;
is the axial force ratio of seismic wall limb;
is the Sectional area of shaded portion of restraining boundary components in Figure 6.4.5-2.
Hoop λ v Hoop and tie bar λ ‘v =λ v/2
Figure 6.4.5-2
6.4.6
Confining boundary element of seismic-seismic wall
When the largest cross-sectional dimension of the seismic wall piers is not larger than 3 times
of the thickness, such seismic wall piers design shall be carried out according to the requirements for columns; and stirrups shall be densified thought overall height of the seismic wall piers when the thickness of rectangular seismic wall limb is not larger than 300mm. 6.4.7
High connection beam with smaller span height ratio may be arranged to double or multiple 61
connection beam with horizontal joints, or other structure with strengthened shear bearing capacity. Within the development length of longitudinal reinforcements in the coupling beam of the top storey, hoops shall be arranged.
6.5 6.5.1
Details of Seismic Design for Frame-seismic Structures seismic wall
The thickness and margin frame arrangement of frames-seismic wall seismic structural wall
shall meet the following requirements: 1
Thickness of a seismic wall shall be not less than 160mm, and also should not be less than
1/20 of the storey height; thickness of the seismic wall at the strengthening portion of the bottom shall not be less than 200mm and also should not be less than 1/16 of the storey height. 2
When end-column is arranged, hidden beam should be arranged on the seismic wall body at
the roof, and the sectional height hereof should not be less than the seismic wall thickness and 400mm. The cross-sectional dimensions of the end-column should be the same as that of the frame column in the same storey and shall also satisfy the requirements for framed columns in Section 6.3 of this code. For the end-columns at the strengthening portion of the bottom of the seismic wall and the end-columns immediately next to the opening, stirrups should be densified according to the requirements for framed columns and thought overall height of end-columns. 6.5.2
The vertical and horizontal distribution reinforcement ratios in web of a seismic wall shall not
be less than 0.25%, the diameter should not be less than 10mm and the reinforcements shall be arranged in two layers. The spacing shall not exceed 300mm. 6.5.3
When the floor beam is connected with the seismic structural wall plane outside, it should not
be supported on the opening connection
beam; seismic structural wall connected with the beam
should be arranged along the beam axis direction and the longitudinal reinforcement for the beam shall be anchored in the seismic wall; or buttress column or hidden column may also be arranged on supporting beam; and the sectional dimension and reinforcement hereof shall be calculated. 6.5.4
The other design details for frame-seismic wall shall meet the requirements of frame and
seismic wall of Section 6.3 and 6.4 in this code respectively. Note: as for the framed structure arranged with less seismic structural wall, the aseismic structural measures for the seismic structural wall shall always comply with the requirements in seismic structural wall specified in Section 6.4.
6.6 6.6.1
Seismic Design Requirements for Slab-column-seismic Structures seismic wall
The aseismic structural measures for slab-column-seismic wall shall comply with the relevant
provisions in Section 6.5; the ones for columns (including end column for seis mic structural wall) and beams shall meet the relevant provisions in Section 6.3. 6.6.2
1
The structural layout of slab-column-seismic wall also shall meet the following requirements: The seismic structural wall thickness shall not be less than 180mm and it should be less than
the storey height or 1/20 the non-support part length; when the house height is larger than 12m, the seismic wall thickness shall not be less than 200mm. 2
Beam frames shall be adopted in building periphery, and margin frame beam should be 62
arranged on periphery of storey and elevator opening. 3
For Intensity 8, slab column joints with supporting board or cColumn cap should be used, and
the thickness (including board thickness) of supporting board or column cap should not be less than 16times the diameter of the column longitudinal reinforcement. The side length of supporting board or column cap should not be less than the sum of 4 times of the board thickness and the column section side. 4 6.6.3
1
The top plate for the first underground storey should be beam and slab structure. The seismic calculation of slab-column-seismic wall shall meet the following requirements: When the building height is larger than 12m, the seismic structural wall shall bear all
earthquake action of the structure; when the building height is not larger than 12m, the seismic structural wall should bear all earthquake action of the structure. The slab and frames part of a layer shall bear at least 20% the seismic shock shear force of the layer. 2
When the earthquake action of slab-column structure is analyzed according to
equal-substitute plane framework, the equal-substitute beam width should be 1/4 the spacing of columns on both sides perpendicular to equal-substitute plane framework direction. 3
The seismic checking for the compact-cutting bearing capacity shall be conducted for slab
column joints, the
compact-cutting caused by imbalance bending moment shall be counted, and the
compact-cutting counter stress design value caused by the imbalance bending moment of earthquake action combination on the joints shall be multiplied by the enhancement coefficient, 1.7, 1.5 and 1.3 respectively for Grade 1, 2 and 3 slab columns. 6.6.4
The slab column joint structures for slab-column-seismic wall shall meet the following
requirements: 1
The width of the hidden beam may be taken as the width of the column plus 1.5 times of the
thickness of slab on the both sides of the column. The reinforcement amount in the top of the hidden beam at supporting face shall not be less than 50% of that of the column strip, and the reinforcement amount in the bottom of the hidden beam shall not be less than 1/2 that of the top. The hoop diameter shall not be less than 8mm and the spacing hereof should not be larger than 3/4 the plate thickness. The limb spacing should not be larger than 2 times the plate thickness. The hoops shall be densified at both ends of the concealed beam. 2
The lap spliced of reinforcements in the slab bottom at the column strip without column
capital should be beyond over 2 times of the development length of longitudinal reinforcements measured from the column face; and should have hooks orthogonal to the slab face at the reinforcement ends. 3
The total section areas of the continuous reinforcements at the slab bottom, that pass the
column core along the both principal axial directions, shall meet the requirements of the following formula: As≥ N G/ f y
(6.6.4)
Where A ——Total cross-sectional area of the continuous reinforcements at the bottom of the slab; s 63
N G ——The column axial compression under the gravity load representative value of the same storey (vertical seismic action should be considered at Intensity 8); f y ——The design value of the tensile strength of reinforcements. 4
According to the requirements in the compact-cutting bearing capacity, the slab column joints
shall be arranged with shear resistant male pin or compact-cutting resisting reinforcement.
6.7 6.7.1
Seismic Design Requirements for Tube Structures
Frame-core-tube structures shall meet the following requirements:
1
Floors between the core tube and the frame should be adopted the beam-slab structural
system; partial storey, adopted with flat slab system, shall be arranged with reinforcement measures. 2
Except reinforcement layer and adjacent up and down layers, the seismic shock shear force
maximum value of layers in frames calculated according to frames -core tube should not be less than 10% the total seismic shock shear force on the structure bottom. Otherwise, the aseismic structural measures for the boundary component shall be reinforced properly and the seismic shock shear force of the core tube seismic wall shall be improved properly; the seismic shock shear force absorbed by the frame of each layer shall not be less than 15% the total seismic shock shear force on the structure bottom. 3
The arrangements of reinforcement layer shall meet the following requirements: 1)
The storeys strengthening with outrigger components shall not be adopted for Intensity
2)
The girder or truss in reinforcement layer shall be penetrated with the seismic wall limb
9.
in core tube; the connection of girder or truss to periphery frame column should be hinge joint or semi rigid joint; 3)
The analysis of the integer structure shall be taken into consideration of the effect due to
the deformation of the storeys strengthening. 4)
The construction procedure and connection details shall be adopted to reduce the effect
due to the storeys strengthening with outrigger components under the vertical deformation caused temperature and the axial compresses of the structure. 6.7.2
The seismic wall in the core tube of the frame-tube structure and in the inner tube of the
tube-in-tube structure shall comply with relevant provisions in Section 6.4 of this code as well as: 1
The thickness of the seismic wall and the vertical and horizontal distribution reinforcements
of web shall comply with the provisions in Section 6.5 of this code; as for the strengthening portion at bottom of tube and the adjacent upper storey, the seismic wall thickness should not be changed if the lateral rigidity has no sudden changes. 2
The boundary elements at the corner of structures assigned to Grade 1 and 2 shall be
strengthened according to the following requirements. For the confine boundary elements in the strengthening portion at bottom of seismic wall, its length shall be taken as 1/4 of the lateral length of the seismic wall segment, and its transverse reinforcement shall only be adopted hoops. For the scope of the overall height above the strengthening portion at the bottom of seismic wall, the confine 64
boundary elements should be arranged according to corner seismic wall. 3 6.7.3
The door opening on the inner tube should not be placed near the corner of tube. The floor girder should not be supported on inner-tube connection beam, and the connection of
floor girder to inner-tube or core tube seismic wall plane shall meet the requirements of Article 6.5.3 of this code. 6.7.4
For core tube or inner tube structures assigned to Grade 1 and 2, the coupling beams in them
with span-to-depth ratio not larger than 2 shall comply with following requirement. When the width of the coupling beam is not less than 400mm, they shall be reinforced with additive two intersecting groups of diagonally placed embedded columns combined with common stirrups; when the width of the beam cross section is less than 400mm but not less than 200mm, besides ordinary stirrups, they shall be reinforced with common stirrups, and diagonally placed reinforcements may be arranged additionally. 6.7.5
The seismic design of the Transference-storey of tube structure shall meet the requirements of
Section E.2 in Appendix E of this code.
7
Multi-storey Masonry Buildings and Multi-storey Masonry Buildings with Bottom-frame 7.1
7.1.1
General Requirements
This chapter is applicable to Frame-seismic wall masonry building on bottom storey or two
bottom storeys, and multi-storey building (also dwelling houses) which the load is borne by the bricking like common brick (including sintering, autoclaved and concrete bricks), perforated brick (including sintering and concrete perforated bricks) and small concrete hollow block. The seismic design of reinforced seismic wall using concrete small hollow block shall meet the requirements in Appendix F of this code. Notes: 1
In this chapter, “fired common clay brick, fired clay perforated brick, concrete small hollow block”
hereinafter refer to “common brick, perforated brick, and small block” respectively. For masonry buildings using other fired bricks and autoclaved bricks, the material property of unit shall have reliable testing data. When the shear strength of the masonry is not less than that of the clay brick masonry, it may be carried out according to relevant provision for clay masonry buildings of this charpter; 2
In this chapter, small concrete hollow block is hereinafter referred to as “small block”;
3
The aseismic design for non-open single-storey bricking building may be conducted on the principles specified in
this chapter.
7.1.2
The total height and number of storeys of multi-storey buildings shall meet the following
requirements: 1
The total height and number of storeys for usual masonry buildings shall not exceed the
limits in Table 7.1.2. Table 7.1.2
Limit Values of Total Height and Number of Storeys
65
Intensity and Design basic earthquake acceleration Minimum Seismic 6
wall thickness of Type of building
seismic wall
7
0.05g
0.10g
8 0.15g
0.20g
9 0.30g
0.40g
(mm) HeightStoreysHeight StoreysHeightStoreysHeight Storeys Height StoreysHeightStoreys
Multi-storey
Common brick
240
21
7
21
7
21
7
18
6
15
5
12
4
Perforated brick
240
21
7
21
7
18
6
18
6
15
5
9
3
perforated brick
190
21
7
18
6
15
5
15
5
12
4
—
—
Small block
190
21
7
21
7
18
6
18
6
15
5
9
3
240
22
7
22
7
19
6
16
5
—
—
—
—
Perforated brick
190
22
7
19
6
16
5
13
4
—
—
—
—
Small block
190
22
7
22
7
19
6
16
5
—
—
—
—
masonry building
Common brick Bottom Frame-seismic wall masonry
Perforated brick
building
Notes: 1
Total height of the building refers to the height from the ground level to top of the main roof slab. For semibasement, the
height is counted from the indoor ground of the basement; for basement and semi-basement with better fixing conditions, the height shall be counted from outdoor ground; for slope roof with garret, the height shall be counted to 1/2 height of the gable; 2
When the indoor and outdoor height difference is larger than 0.6m, the total height of the building shall be permitted to increase
appropriately but shall not be larger than 1.0m; 3
Limit values of total height and number of storeys for buildings assigned Precautionary Category B shall be permitted determined
according to the local Precautionary Intensity, but limits value of total height shall be decreased by 3m and of the storeys shall be decreased by one; 4
2
The small block buildings in this table do not including the reinforced small-sized block buildings.
For multi-storey buildings with rather less transverse seismic wall, as well as hospitals or
schools, the limits value of total height shall be decreased by 3m from the values in Table 7.1.2, and of the storeys shall be decreased by one. For multi-storey buildings with a few of transverse seismic wall, the storeys shall continue be reduced one storey. Note: Building with rather less transverse seismic wall refer to that rooms with span larger than 4.20m takes up more than 40% of the areas in the same storey. Among them, the case that the room with bay no larger than 4.2m account for the total area of this storey by less than 20%, and the rooms with bay larger than 4.8m account for the total area of this storey by over 50% refers to “less transverse seismic wall”
3
In Intensity 6 and 7, for multi-storey brick dwelling houses with rather less transverse seismic
wall, when the strengthened measures has be taken according to the provision and the seismic capacity of seismic wall has sufficient, the total height and storeys shall be permitted to adopt the limits in Table 7.1.2. 4
As for Autoclaved lime-sand brick and autoclaved fly ash brick building, the number of 66
storeys
of the building shall be less by a storey than the ones with common brick and the total height
shall be reduced by 3m if the shear strength of bricking masonry only reaches 70% the one of ordinary clay brick masonry. The requirements in number of storeys and total height of the building are same to ones of common brick building. 7.1.3
For the common brick, perforated brick and small block buildings, the storey-height shall not
exceed 3.6m. For the framed storeys of the Mmasonry buildings with bottom-frame and the masonry buildings with inner-frame, the storey-height shall not exceed 4.5m; when adopting confined masonry seismic wall at the bottom storey, the storey-height of this bottom storey shall not exceed 4.2m. Note: In the case of special service need, the storey-height of common brick building with the confine construction shall not exceed 3.9m.
7.1.4
Maximum ratio of the total height to total width for multi-storey masonry buildings should
meet those specified in Table 7.1.4. Table 7.1.4 Intensity
Maximum Ratio of Total Height to Total Width for Buildings
6
7
8
9
2.5
2.5
2.0
1.5
Max. height-to-Width ratio
Notes: 1 2
7.1.5
The total width of buildings with an external corridor does not including the width of the corridor;
When the plain of the building is close to square, the ratio shall be reduced accordingly.
Maximum spacing of adjacent transverse seismic wall in buildings shall not exceed the
requirements in Table 7.1.5. Table 7.1.5
Maximum Spacing of Adjacent Transverse Seismic wall (m) Intensity
Type of building and type of floor or roof
Multi-storey
Cast-in-situ or precast-monolithic reinforced concrete building and roof
6
7
8
9
15
15
11
7
11
11
9
4
9
9
4
-
(cap) masonry Fabricated reinforced concrete building and roof building Timber building roof Multi-storey masonry with
Same as multi-storey All masonry storeys above the framed storeys
-
bottom-frame building
masonry First storey or first and second frame storeys
Notes: 1
18
15
11
-
For top storey of multi-storey masonry buildings, the maximum spacing requirement of transverse seismic wall shall be
permitted loosened, but corresponding reinforcement measures shall be taken; 2
When the thickness of the perforated brick seismic transverse seismic wall is 190 mm, the maximum transverse seismic wall
spacing shall be reduced by 3m than the values listed in the table.
67
7.1.6
The limitation of local dimension for masonry seismic wall should meet the requirements in
Table 7.1.6: Table 7.1.6
Limitation of Local Dimension for Masonry Seismic wall (m)
Location
Intensity 6
Intensity 7
Intensity 8
Intensity 9
Min. width of a bearing seismic wall between windows
1.0
1.0
1.2
1.5
1.0
1.0
1.2
1.5
1.0
1.0
1.0
1.0
1.0
1.0
1.2
2.0
0.5
0.5
0.5
0.0
Min. distance from a bearing exterior seismic wall end to the edge of the door or window opening Min. distance from a non-bearing exterior seismic wall end to the edge of the door or window opening Min. distance from the salient angle of inter seismic wall to the edge of the door or window opening Max. height of parapet without anchorage (not at entrance) Notes: 1
If the partial position is under size, the local reinforcement shall be taken for compensation, and the minimum width hereof
should be less than 1/4 the storey height and 80% the values listed in table; 2
7.1.7
Parapet in exit and/or entrance shall be anchored;
The structural system of multi-storey masonry buildings shall meet the following
requirements: 1
The structural system of bearing by transverse seismic wall or of bearing by both longitudinal
and transverse seismic wall shall be adopted with priority. Structural system adopting combined masonry seismic wall and concrete seismic w all for bearing load shall not be adopted. 2
The arrangement of vertical and horizontal masonry seismic structural wall shall meet the
following requirements: 1)
The arrangement of transverse and longitudinal seismic wall should be symmetrical,
even, and aligned in-plain, shall be continued from footing to top, and the quantity of vertical and horizontal seismic wall should not differ greatly. 2)
The convex-concave of plane outline shall not exceed 50% of the typical size; if it
exceeds 25% of the typical size, the reinforcement measures shall be taken for building corner; 3)
The dimension of local large opening on slab should not exceed 30% the slab width,
and no opening shall be arranged on both sides of a seismic wall simultaneously; 4)
When the height difference of floor-slab of building storey split exceeds 500 mm, the
arrangement shall be calculated according to two storeys; the seismic wall on split-storey shall be arranged with reinforcement measures; 5)
The width of seismic wall on same axes should be uniform; the opening area of the
seismic wall surface, for Intensity 6 and 7, should not be larger than 55% the total seismic wall surface area; for Intensity 8 and 9, it should not be larger than 50%. 6)
Inner longitudinal seismic wall shall be arranged on the middle of the building along the
width direction, and the accumulative total length should not be less than 60% the total length of the 68
building (seismic wall sections with height-width ratio larger than 4 are not counted in). 3
The seismic joints should be installed according if the building has one of the following cases;
the width shall be determined according to Intensity and building height, and it may be taken as 70~100mm: 1)
The height difference in elevation of the building is larger than 6m;
2)
Buildings with split-storey and the floor-slab height difference larger than 1/4 the storey
3)
The rigidity and mass of every parts of a structure are completely different.
height;
4
The staircase should not be arranged at the end and corner of the building.
5
Corner window shall not be arranged at building corner..
6
Cast-in-situ reinforced concrete storey and roof should be adopted for buildings with less
transverse seismic wall and larger span. 7.1.8
The structural arrangement of masonry buildings with bottom-frames shall meet the following
requirements: 1
All of the masonry wells above the framed storey, excluding certain seismic wall sections
near to staircase, shall be or shall basically be level by the frame-beams or seismic wall at the bottom. 2
A certain number of uniformly distributed seismic wall shall be installed along both the
longitudinal and trans-versal directions at the bottom of the buildings. For buildings with Frame-seismic wall masonry on bottom storey in Intensity 6 and the total number of storeys less than or equal to 4, they shall be allowable to adopt masonry seismic structural wall with restraining common brick masonry or small block masonry embedded between frames. But the additional axial force and shear force of masonry seismic wall on the frames shall be considered and the seismic checking for bottom storey shall also be conducted. Reinforced concrete seismic wall and restraining masonry seismic wall shall not be adopted simultaneously at same direction. For Intensity 8, reinforced concrete seismic wall shall be adopted, and for Intensity 6 and 7, reinforced concrete seismic wall or reinforced small block masonry seismic wall shall be adopted. 3
In the longitudinal and transversal directions of multi-storey brick building with framed first
storey, the lateral rigidity ratio of the second storey to the first storeys shall not be larger than 2.5 for Intensity 6 and 7, and 2.0 for Intensity 8; both shall not be less than 1.0. 4
In the longitudinal and transversal directions of multi-storey brick building with framed first
and second storeys, the lateral rigidity ratio of third storey to second storey shall not be larger than 2.0 for Intensity 6 and 7, and 1.5 for Intensity 8; both shall not be less than 1.0. 5
For the wells of masonry buildings with bottom-frames, the strip foundation, raft foundation
or pile foundation with good integrity shall be adopted. 7.1.9
The seismic design of reinforced concrete structural parts of Masonry Buildings with
bottom-frames and inner-frames shall meet the requirements both in this Chapter and relevant requirements in Chapter 6 of this code. Meanwhile, the seismic measure Grades for Masonry Buildings with bottom-frame, the frame and the reinforced concrete seismic wall shall be taken as Grade 3, 2, and 1 for Intensity 6, 7, and 8 respectively. And the seismic measure Grades for Masonry 69
Buildings with inner-frames shall be taken as Grade 4, 3, and 2 for Intensity 6, 7, and 8 respectively.
7.2 7.2.1
Essentials in Calculation
The base shear method may be used in the seismic calculation for multi-storey masonry
buildings, and masonry buildings with bottom-frame or inner-frame, and the seismic effects shall be adjusted in accordance with the provisions of this code. 7.2.2
For masonry buildings, the seismic checking of seismic wall may only be made that with
greater subordinating areas or with lesser vertical stress. 7.2.3
When carrying out seismic shear force distribution and seismic checks, the storey equivalent
lateral rigidity of the masonry seismic wall shall be determined according to the principles as follows: 1
For the calculation of rigidity, the influence on height-width ratio of seismic wall-segment
shall be taken into consideration. When this ratio is less than 1, only shear deformation of seismic wall needs to be taken into account. When this ratio is not larger than 4 and not less than 1, both the bending and shear deformation shall be taken into consideration. When this ratio is larger than 4, the equivalent lateral rigidity may be taken as 0.0. Note: The height-width ratio refers to the ratio between the height of storey and the lateral-length of seismic wall.
2
The seismic wall-segments should be divided according to the openings of the door and the
windows. The rigidity calculated according gross seismic wall surface in the small opening seismic wall sections may be multiplied by the opening ratio and the opening reduced factors in Table 7.2.3: Table 7.2.3
Opening Reduced Factors
Opening ratio
0.10
0.20
0.30
Reduced factor
0.98
0.94
0.88
Notes: 1 The opening rate is the ratio between the opening area and the gross area of the seismic wall; when the height of window opening is larger than 500mm, it shall be treated as door opening. 2
When the opening center line deviates larger than 1/4 the seismic wall section length from the seismic wall section
center line, the influence coefficient in the table shall be reduced by 0.9; when the ceiling height of the door opening is larger than 80% the storey height, the values listed in the table is not applicable; when the window opening height is larger than 50% the storey height, it is treated as a door opening.
7.2.4
Seismic effects of Masonry Buildings with bottom-framed shall be adjusted according to the
following requirements: 1
For Masonry Buildings with framed first storey, the first storey longitudinal and transversal
seismic shear force design value shall be multiplied by an enhancement coefficient. The value of this enhancement coefficient shall be permitted selecting in the range from 1.2 to 1.5 according to the lateral rigidity ratio between the second storey and the fist storey. The larger one of the lateral rigidity ratio of the second storey and the bottom floor shall be adopted. 2
For Masonry Buildings with framed first and second storeys, the longitudinal and transversal
seismic shear force design value of the first storey and the second storey shall all be multiplied by an enhancement coefficient. The value of this enhancement coefficient shall be permitted selecting in the 70
range from 1.2 to 1.5 according to the lateral rigidity ratio. The larger one of the lateral rigidity ratio of the second storey and the first storey shall be adopted. 3
All of longitudinal and transversal seismic shear force design value of the first storey and the
second storey shall be resisted by the seismic wall of corresponding direction separately, and the distribution shall be made according to the lateral rigidity ratio of every s eismic wall. 7.2.5
Seismic effect of frames in masonry buildings with bottom-frame should be determined by the
following method: 1
The seismic shear force and axial force of the columns of the framed storeys should be
adjusted according to the following requirements: 1)
Design value of seismic shear force resisted by framed columns may be determined in
proportion to the effective lateral rigidity of every lateral-force-resisting component. The value of the effective lateral rigidity may not be reduced for the frame, and may be multiplied by 0.30 for the reinforced concrete seismic wall, and may be multiplied by 0.20 for the clay brick sei smic wall. 2)
Additional axial force caused by the seismic overturning moment shall be considered in
the calculation of the axial force of the framed column. The seismic overturning moment carried by the elements in all axes may be determined in proportion of the lateral rigidity of seismic-seismic wall and frames in the bottom approximately. 3)
When the length-width ratio of the roof between seismic structural walls is larger than
2.5, the seismic shear force and axial force absorbed axes of the frame columns shall be accounted into the influence of plane deformation of the roof. 2
When calculating the seismic combinatory inner force for the reinforced concrete spandrel
girder for Masonry Buildings with bottom-frames, proper calculation figure shall be adopted. If the composite effect of the upper seismic wall and its spandrel girder may be put into the consideration, the unfavorable influence on that caused by the cracking of seismic wall during earthquake shall also be taken into consideration, relevant bending moment factors and axial factors may also be adjusted. 7.2.6
The design value for seismic shear strength along the ladder shaped damage of various
masonry structures shall be determined according to the following formula: f vE=ζ N f v
(7.2.6)
Where f vE ——The design value for seismic shear strength along the ladder shaped damage of masonry; f v ——The design value for shear strength along the ladder shaped damage of masonry; ζ N ——Normal stress influence factors for the seismic shear strength of masonry, and shall be taken according to Table 7.2.6. Table 7.2.6
Normal Stress Influence Factor of Masonry Strength σ 0/ f v
Type of masonry
Common brick, perforated brick
0.0
1.0
3.0
5.0
7.0
10.0
15.0
20.0
0.80
0.99
1.25
1.47
1.65
1.90
2.05
—
71
Small block
Note:
7.2.7
—
1.23
1.69
2.15
2.57
3.02
3.32
3.92
σ 0 refers to the mean pressure of the masonry cross section corresponding to gravity load representative value.
The seismic shear capacity for seismic wall of common bricks and perforated bricks shall be
checked according to the following requirements: 1
Generally, the check shall be made according to the following formula: V ≤ f vE A/γRE
(7.2.7-1)
Where V ——Shear of seismic wall of masonry structures; f vE ——Design value for seismic shear strength along the ladder shaped damage of masonry; A ——Cross-sectional area of seismic wall, the gross area of cross section for perforated brick seismic wall; γRE ——Seismic adjusting factor for shear bearing capacity, for bearing seismic wall shall be taken according to Table 5.4.2 of this code, for self-bearing seismic wall shall be taken as 0.75.
2
For horizontal reinforced seismic wall, the seismic shear bearing capacity shall be checked in
accordance with following formula:
V ≤
1 γ RE
( f vE A + ζ s f y A sh )
(7.2.7-2)
Where f y ——Design value of reinforcement tensile strength; Ash ——The total areas of horizontal reinforcements in height of a storey, the reinforcement ratio shall not be less than 0.07% and not larger than 0.17%; ζ s ——The participation factor of reinforcement, may be taken according to Table 7.2.7. Table 7.2.7
Participation Factor of Reinforcement
Ratio of height to width for seismic wall
0.4
0.6
0.8
1.0
1.2
ζs
0.10
0.12
0.14
0.15
0.12
3
When the checking calculation with Formula (7.2.7-1) and (7.2.7-2) cannot satisfy the
requirements, the raising effect on shear bearing capacity, made by the tie columns (which the cross section is not less than 240mm× 240mm (240mm× 190mm if the seismic wall thickness is 190mm), and the spacing is not larger than 4m) uniformly arranged in the middle of the seismic wall segment, may be counted, and the shear bearing capacity may be worked according the following simplified method:
V ≤
1 [η c f vE ( A－A c ) + ξ c f t Ac + 0.08 f yc A sc + ξ s f yh Ash ] γ RE
(7.2.7-3)
72
Where,
Ac ——Total section areas of the tie column in the middle (for horizontal and inner longitudinal seismic wall and Ac >0.15A, it is taken as 0.15A; for external longitudinal seismic wall and Ac >0.25A, it is taken as 0.25A);
f t ——Axial tensile strength design value of concrete of middle tie column;
A sc ——Cross section total area of longitudinal reinforcement of middle tie column (it i s taken as 1.4 % when the reinforcement ratio is not larger than 0.6 % and larger than 1.4%);
f yh , f yc ——Tensile strength design values of seismic wall horizontal reinforcement and tie column reinforcement;
ξ c ——Participation service factor of middle tie column: it is taken as 0.5 when a root is arranged in middle; and 0.4 when multiple roots are arranged;
η c ——Restraining correction coefficient of seismic wall: 1.0 under general condition; 1.1 when the tie column spacing is not larger than3.0m;
A sh ——Total horizontal reinforcement area of vertical section of inter-storey seismic wall, taken as 0.0 without horizontal reinforcement.
7.2.8
For small blocks seismic wall, the seismic shear bearing capacity shall be checked in
accordance with following formula:
V ≤
1 γ RE
[ f vE A + (0.3 f t Ac + 0.05 f y A s )ζ c ]
(7.2.8)
Where f ——Design value of concrete axial tensile strength of core-column; t Ac ——Total cross-sectional area of core-columns; As ——Total cross-sectional area of reinforcements in core-column; f ——Design value of concrete tensile strength of core-column; t ζ c ——The participation factor of core-column, may be taken according to Table 7.2.8. Note: When both core-columns and tie-columns are installed together, the cross-sectional areas of the tie-column may 73
be treated as the cross-sectional areas of the core-column, and the reinforcement of the tie-column may also be treated as that of the core-column. Table 7.2.8
Participation Factor of Core-column
Hole filling rate ρ
ρ<0.15
0.15≤ ρ<0.25
0.25≤ ρ<0.5
ρ≥0. 5
ζc
0.0
1.0
1.10
1.15
Note: Hole filling rate refers to the ratio of number of core-columns (including numbers tie colum and holes) to total hole numbers.
7.2.9
For multi-storey brick building with framed first storey, when seismic wall with common
bricks filled in the frames and meet the detail requirements in Article 7.5.4 and 7.5.5 of this code, the seismic check shall meet the following requirements: 1
The axial and shear force of the frame columns in the first storey shall take into consideration
of the additional axial and shear force according to the following formulae: N f =V w H f /l
(7.2.9-1)
V f=V w
(7.2.9-2)
Where V w ——The seismic shear force design value distributed to the brick seismic wall; for seismic wall exist on both sides of the column, the value may be taken as the greater one; N ——Additional axial pressure design value of the frame column; f V ——Additional shear force design value of the frame column; f H f , l ——The storey height and span of the frame separately. 2
The seismic bearing capacity of the seismic wall made with common bricks filled in the
frame and the frame columns at the two ends of seismic wall shall be checked according to the following formula:
V ≤
1 γ RE c
∑ ( M
u yc
l )+ + M yc
1 γ REw
∑ f A vE
w0
(7.2.9-3)
Where V ——The seismic shear force design value of the filled common brick seismic wall and the frame columns at the two ends of seismic wall; Aw0 ——Calculated horizontal sectional area of the brick seismic wall. When seismic wall is no opening, take as 1.25 times of the actual sectional area; when seismic wall is opening, take as the net sectional area, but the sectional area of the seismic wall, which width less than 1/4 of the opening height, is not considered; u l , M yc ——Non-seismic bending bearing capacity design values at the upper and lower end M yc
of the frame columns in the first storey and it may be determined by the provision in the current national standard “Code for Design of Concrete Structure” GB 50010; 74
H 0 ——Calculated height of first storey frame column; when there are brick seismic wall on the both sides, take as 2/3 of clear height of the column; in other cases, take as the clear height of the column; γREc ——Seismic adjusting factor for first storey frame column bearing capacity, and may be taken as 0.8; γREw ——Seismic adjusting factor for filled common brick seismic wall bearing capacity, and may be taken as 0.9.
7.3
Details of Seismic Design for Multi-storey Clay Masonry Buildings
7.3.1 The cast-in-situ reinforcement concrete tie-columns (hereinafter referred to as tie-column) for
multi-storey brick masonry buildings shall be installed in accordance with the following requirements: 1
The location installed of tie-column shall meet the requirements in Table 7.3.1 generally.
2
For multi-storey gallery-type or one-sided corridor buildings, the tie-columns shall be
installed according to those set out in Table 7.3.1, but the building assumed with one more storey, and the longitudinal seismic wall on the both sides of the one-sided corridor shall be regarded as exterior seismic wall. 3
For buildings with rather less transversal seismic wall, as well as schools and hospitals, the
tie-columns shall be installed in accordance with those set out in Table 7.3.1, but the building assumed with one more storeys. When such buildings adopt the gallery-type or one-sided corridor, that shall also comply with provision in Item 2 of this article; but the following building assumed with two more storeys: does not exceed 4 storeys for Intensity 6, or 3 storeys for Intensity 7, or 2 storeys for Intensity 8. 4
For buildings which the storey has less transverse seismic wall, the tie column shall be
arranged according to “number of storey increased by two”. 5
As for autoclaved lime-sand brick and autoclaved fly ash brick masonry buildings, the tie
column shall be arranged according to “number of storey increased by a storey”
in accordance with
the requirements of Item 1~4 of this article; but for Intensity 6 with not more than 4 storeys, Intensity 7 with not more than 3 storeys and Intensity 8with not more than 2 storeys, it shall be treated according to “number of storey increased by two”. Table 7.3.1
Requirements for Arrangement of Tie-columns for Masonry Buildings
Number of storeys in building Location of installation Int. 6
4, 5
Int. 7
3, 4
Int. 8
2, 3
Int. 9
Four corners of the stair shaft and
Intersections of each 12m or the unit transversal
elevator; location corresponding to
seismic wall and exterior longitudinal seismic
two ends of stair segments;
wall;
Four quoins and reentrant of the
Intersections of every other transversal seismic
exterior seismic wall; Intersections
wall (axis) and exterior seismic wall
75
6
5
4
2
of the transversal seismic wall with
Intersections of gable and interior seismic wall
the split-level and the exterior longitudinal seismic wall; Both sides of bigger openings; Intersections of ≥6
7
≥5
≥3
interior seismic wall and exterior
Intersections of interior seismic wall and exterior seismic wall: smaller piers of the interior seismic wall;
longitudinal seismic wall at large
Intersections of interior longitudinal and
rooms
transversal seismic wall
Note: As for larger opening, in inner seismic wall, refers to the one not smaller than 2.1m; in outer seismic wall, it may be widened properly when tie column is arranged on the connection of inner and
outer seismic wall. But the seismic wall
close to opening shall be reinforced.
7.3.2
The tie-columns of the multi-storey common brick masonry buildings shall meet the following
requirements; 1
The minimum cross section for the tie-column may adopt 240mm×180mm (180mm×190mm
if the seismic wall thickness is 190mm), the longitudinal bars should adopt 4 φ12; spacing of the stirrups shall not be greater than 250mm, besides, in the upper and lower ends of the tie-column, the spacing of stirrups shall be reduced accordingly. When exceeding 6 storeys for Intensity 7, exceeding 5 storeys for Intensity 8, and for Intensity 9, the longitudinal reinforcements of the tie-column shall adopt 4φ14, and the spacing of stirrups shall not exceed 200mm. For the tie-columns in the corners of the building, cross section and stirrups shall be increased accordingly. 2
The connection of the tie-column and the adjacent seismic wall shall be built into
horse-toothed joints, the 2φ6 tie bars shall be arranged in spacing each 500mm along the height of the seismic wall, the length extending into the seismic wall at each side should not be less than 1m. For 1/3 storeys on bottom in Intensity 6 and 7, 1/2 storeys on bottom in Intensity 8, and all storeys in Intensity 9, above tie reinforcing mat shall be arranged horizontally along full length of the seismic wall. 3
At the connection of the tie-column and the ring-beam, the longitudinal bars of the
tie-column shall be arranged throughout the ring-beam to ensure the continuation of longitudinal reinforcements in the tie-column. 4
The tie-columns may not establish individual footing, but they shall extend to 500mm into
the underground level, or shall be connected with the foundation ring-beam, which buried depth less than 500mm underground. 5
When the building height and the number of storeys are close to the limit values of Table
7.1.2, the spacing of tie-columns within the longitudinal and transversal seismic wall shall also meet the following requirements: 1)
For the transversal seismic wall, the spacing of tie-columns should not be greater than 2
times of the storey height, and this spacing of tie-columns in lower 1/3 of storeys should be reduced accordingly; 2)
For the longitudinal seismic wall, when the bays of building are greater than 3.9m, the
exterior longitudinal seismic wall shall be adopted strengthening measures; the spacing of tie-columns of the interior longitudinal seismic wall should not be greater than 4.2m. 7.3.3
The cast-in-situ reinforced concrete ring-beam of multi-storey common brick masonry 76
buildings shall be installed in accordance with the following requirements: 1
For the buildings which precast reinforced concrete or timber floors and roof are adopted, the
ring-beams shall be installed according to the requirements of Table 7.3.3; when the buildings assigned to bearing longitudinal seismic wall system, the spacing between ring-beams on the transversal seismic wall shall be reduced accordingly. 2
Only the building with cast-in-situ or assembly-monolithic reinforcement concrete floors and
roof that have reliable connection with the seismic wall, the ring-beams shall be permitted not installed. But the strengthened reinforcements of cast-in-situ slabs shall be arranged along the seismic wall perimeters and shall be reliably connected with corresponding tie-columns. Table 7.3.3
Requirements for Installation of Cast-in-situ Reinforcement Concrete Ring-beam in Masonry Buildings Intensity
Type of seismic wall 6, 7
8
At roof level, each floor level
At roof level, each floor level
9
Exterior seismic wall and At roof level, each interior longitudinal
floor level seismic wall Ditto; the spacing at roof shall not be Ditto;
Ditto;
greater than 4.5m; Interior transversal seismic wall
along all transversal seismic wall at roof and the spacing all transversal seismic the spacing at the floor shall shall not be greater than 4.5m; corresponding location of
wall at roof and each
not be greater than 7.2m; the tie-column
floor
corresponding location of the tie-column
7.3.4
The details of cast-in-situ reinforced concrete ring-beam in multi-storey brick masonry
buildings shall meet the following requirements: 1
The ring-beam shall be enclosed; at the location of opening, the ring-beam shall be spliced
with two limbs along the upper and lower of opening. The ring-beams should be installed in the same level of the precast slabs or immediate next to the bottom of the slab; 2
For no transversal seismic wall exists the within of ring-beam spacing required by Article
7.3.3, the reinforcements in the floor girder or the joint between precast slabs shall be used for the replacement of ring-beam; 3
The cross-sectional height of the ring-beam shall not be less than 120mm, and the
reinforcements shall meet the requirements in Table 7.3.4. The ring-beams added according to the requirements of Item 3 of Article 3.3.4 of this code, the cross-sectional height shall not be less than 180mm, and the reinforcement bar shall not be less than 4 φ12. Table 7.3.4 Reinforcement
Requirements for Reinforcement Arrangement in Ring-beam of Masonry Buildings Intensity
77
6,7
8
9
Min. longitudinal bar
4φ10
4φ12
4φ14
Max. stirrup spacing (mm)
250
200
150
7.3.5
Roof and floors of multi-storey brick masonry buildings shall meet the following
requirements: 1
The length for cast-in-situ reinforced concrete roof or floor slabs extending to the transversal
and longitudinal seismic wall shall not be less than 120mm. 2
For precast reinforcement concrete floor or roof slab and the ring-beam is not installed at the
same level of the slab, the length for the slab end extending into the exterior seismic wall shall not be less than 120mm; into interior seismic wall, not less than 100mm; and into beam, not less than 80mm. 3
When precast slab with span is larger than 4.8m and parallel to the exterior seismic wall, the
side of the precast slab next to the exterior seismic wall shall be tied with the exterior seismic wall or ring-beam. 4
Roof of large room at end. the precast slabs shall be tied each other as well as with beam, wal
or beam ring when the bottom slabs are arranged for beam ring of roof of the building at Intensity 6 and roof or cap of the building at Intensity 7~9. 7.3.6
The reinforcement concrete girders or trusses of the roof or floor system shall be reliably
connected with the seismic wall, column (including tie-column) or ring-beam.; the individual brick column shall not be used. The supporting component for the RC girder with span lager then 6m shall be strengthen and formed by composite masonry, and shall meet the demands of bearing capacity 7.3.7
For the rooms with length larger than 7.2m of Intensity 6 and 7, and outer seismic wall corner
and internal and external seismic wall connection of Intensity 8 and 9, the reinforcement (2 φ6) along full length and the tie meshes welded by φ4 distributed short bars or φ4 spot welding meshes shall be arranged every other 500mm along the seismic wall height. 7.3.8
1
The staircase shall also meet the following requirements: For transversal seismic wall and exterior seismic wall of the staircase at top storey, 2φ6
reinforcement bars shall be installed overall length of seismic wall and installed in each 500mm along the height of the seismic wall. For Intensity 7 to 9, a 60mm thick reinforcement concrete strip or a reinforced brick course shall be installed at the landing platform or middle level of the storey in other storeys of the staircase. For reinforced brick course, the strength Grade of mortar shall not be less than M7.5, and the longitudinal reinforcement bars shall not be less than 2 φ10. 2
The developing length of the girder, which at the staircase or the salient angle of the interior
seismic wall for the vestibule, shall not be less than 500mm, and the girder shall be connected with the ring-beam. 3
The fabricated stair section shall be reliably connected with the beam of the landing platform;
for Intensity 8 and 9, the fabricated stair section shall not be adopted; the stairs with the cantilevered steps tread from seismic wall or the steps riser interposed the seismic wall shall not be adopted, and the plain brick railing shall not be adopted. 4
For staircase or elevator shaft exceeding the roof level, the tie-column shall extend to the 78
seismic wall top and shall connect with the ring-beam of the seismic wall top. And its intersection of the interior and exterior seismic wall, 2φ6 tie-bars developing overall length of seismic wall and the tie mesh composed of φ4 short steel bars by spot-welding in plane or the φ4 spot-welded meash shall be installed in each 500mm along the height of the seismic wall. 7.3.9
The trusses of pitch roof shall be reliably connected with the ring-beam of the top storey of
building; the purloins and the roof slabs shall be connected with the seismic wall or trusses. The tiles of eaves course at the entrance and exit of the building shall be anchored to the roof components. When purlines are adopted, the stepwise piers at the top of longitudinal interior seismic wall of the top storey should be built up to support the gables, arranged with tie column. 7.3.10
The plain brick lintels shall not be adopted at the door or window openings. The supporting
length of lintel shall not be less than 240mm from Intensity 6 to Intensity 8, and shall not be less than 360mm for Intensity 9. 7.3.11
For Intensity 6 and 7, the precast balcony slabs shall be reliably connected with the
ring-beam and the cast-in-situ strip of the precast floor slab. For Intensity 8 and 9, precast balcony shall not be used. 7.3.12
The post-built non-bearing partition, flue, air duct and refuse channel seismic wall shall
comply with relevant provision of Section 13.3 in this code. 7.3.13
The foundation (included the pile capping) of the same structural unit should adopt
foundation of the same type. The bottom of foundation shall be buried at the same level; otherwise, added foundation ring-beams shall be installed, and foundation shall be stepped on a slope 1:2. 7.3.14
For the total height and number of storeys of multi-storey common brick and perforated brick
dwelling buildings exceed the limit values listed in Table 7.1.2, the strengthening measures shall be taken with following provisions: 1
The size of the largest bay in the building should not be larger than 6.6m.
2
Within the same structural unit, the number of staggered-axis transversal seismic wall should
not exceed 1/3 of the total number of seismic wall; more, successive staggered-axis seismic wall should not exceed two. The added tie-columns shall be installed at all of intersection of the staggered-axis seismic wall and longitudinal seismic wall, and the floors and roof shall adopt cast-in-situ reinforced concrete slabs. 3
The width of opening in the transversal seismic wall and the interior longitudinal seismic wall
should not be greater than 1.5m; the width of opening in the exterior longitudinal seismic wall should not exceed 2.1m or 50% of the bay dimension. More, the locations of these opening on the interior and exterior seismic wall shall not influence on the integral connections between the interior and/or exterior longitudinal seismic wall and transversal seismic wall. 4
The cast-in-situ strengthening reinforcement concrete ring-beam shall be installed for each
transversal and longitudinal seismic wall in the floors and roof. The cross-sectional height of the ring-beam should not be less than 150mm, the upper and lower longitudinal reinforcement reinforcements shall not be less than 3φ10, the stirrup diameter shall not be less thanφ6, and the spacing of stirrup shall not be larger than 300mm. 5
In the intersections of all transversal and longitudinal seismic wall as well as the middle of
the transversal seismic wall, the added tie-columns shall be installed in accordance with following 79
requirements; the column spacing within the transversal seismic wall should not be larger than the storey height, the spacing of column within the longitudinal seismic wall should not be greater than 3.0m; the minimum cross section of tie-columns should not be less than 240mm×240mm (240mm×190mm if the seismic wall thickness is 190mm); the reinforcements should meet the requirements in Table 7.3.14. Table 7.3.14
Requirements for Longitudinal Reinforcements and Stirrups in the Added Tie-column Longitudinal reinforcement Max.
Location
Min.
Stirrup Min.
Spacing in Scope of densified
reinforcement
reinforcement
diameter
ratio (%)
ratio (%)
(mm)
Min. densified zone
zone (mm)
Corner column
14 1.8
14 1.4
Full height
0.8
Side column Middle column
diameter (mm)
0.6
12
Upper end 700
100
6
Lower end 500
6
The floors and roof of the same structural unit shall be installed at the same level.
7
At the windowsill level of the top and first storey of the building, the cast-in-situ reinforced
concrete horizontal strip should be installed along overall length of the transversal seismic wall and longitudinal seismic wall. The cross-sectional height of this strip shall not be less than 60mm. The width shall not be less than the seismic wall thickness, for longitudinal distribution reinforcement, it shall not be less than 2φ6; for transversal one, it shall not be less than φ6. The spacing shall not be larger than 200mm.
7.4 7.4.1
Details of Seismic Design for Multi-storey Small-block Buildings
The reinforced concrete core columns (hereinafter refer to core-column) for small-block
buildings shall be installed in accordance with the requirements of Table 7.4.1. For buildings with rather less transversal seismic wall such as hospital and school, core-columns shall be installed according to Table 7.4.1, the requirements on the building assumed with one more storeys shall be raised according to Item 2, 3 and 4 of Article 7.3.1. Table 7.4.1 Number of storeys Int. Int. Int. Int. 6
7
8
9
Requirements for Core-columns Installed in Small-block Buildings
Location of core-columns Corner of exterior seismic wall, four corners of
Number of core-columns (filled holes) Corners of the exterior seismic wall, 3 holes shall be filled;
staircase, seismic wall body corresponding to the
intersection of interior and exterior seismic wall, 4 holes; seismic
upper and lower ends of inclined stair part;
wall body corresponding to the upper and lower ends of inclined
4, 5 3, 4 2, 3
stair part, 2 holes intersection of interior and exterior seismic wall in large rooms; intersections of transversal seismic wall in storey-spilt and exterior longitudinal seismic wall;
80
intersections of each 12m or the unit transversal seismic wall and exterior longitudinal seismic wall
6
5
4
Ditto; intersection of bay transversal seismic wall (axis) and exterior longitudinal seismic wall
7
6
5
2
Ditto;
Corners of the exterior seismic wall, 5 holes shall be filled; intersection of interior and exterior seismic wall, 4 holes;
Intersection of interior seismic wall (axis) and intersection of interior seismic wall, 4~5 holes; both sides of exterior longitudinal seismic wall; opening, 1 hole intersection of interior longitudinal seismic wall and transversal seismic wall (axis), both sides of openings 7
≥6
≥3
Ditto;
Corners of the exterior seismic wall, 7 holes shall be filled; intersection of interior and exterior seismic wall, 5 holes;
The spacing of the transversal seismic wall intersection of interior seismic wall, 4~5 holes; both sides of core-column shall not be greater than 2m opening, 1 hole Note: In locations such as the corners of the exterior seismic wall, intersection of the interior and exterior seismic wall, and corners of staircase, it shall be permitted adopted tie-columns to replace corresponding core-columns.
7.4.2
The core-columns of multi-storey small-block buildings shall meet following requirements:
1
The cross section of the core-column should not be less than 120mm×120mm.
2
The concrete strength Grade of the core-column shall not be less than Cb20.
3
The longitudinal bars of the core-column shall through overall seismic wall and connect with
the ring-beam; the longitudinal bar shall not be less than 1φ12, and than 1φ14 for the building exceeds 5 storeys at Intensity 6 and 7, exceeds 4 storeys at Intensity 8 and at Intensity 9. 4
The core-column shall extend to 500mm underground level or connect with foundation
ring-beam with a buried depth less than 500mm. 5
The core-columns which improve the seismic wall seismic capacity should be distributed in
the seismic wall evenly, and the maximum clear spacing shall not be larger than 2.0m. 6
The tie reinforcing mat shall be arranged on the seismic wall connection or core column and
seismic wall connection of multi-storey small block building, and it may be made of steel bars with diameter 4mm by spot welding. The meshes shall be arranged horizontally by the spacing not larger than 600mm (along seismic wall height) along full length of the seismic wall body. they are arranged for 1/3 storeys on bottom at Intensity 6 and 7; 1/2 storeys on bottom at Intensity 8 and all storeys at Intensity 9, and the spacing along seismic wall height shall not be larger than 400 mm. 7.4.3
The tie-columns used to replace core-columns in small-block buildings shall meet the
following requirements: 81
1
The minimum cross section of the tie-column may be adopted 190mm×190mm, the
longitudinal bars should adopt 4φ12, the spacing of stirrups should not be larger than 250mm and should be densified at the upper and lower end of the column accordingly. When the building exceeds 5 storeys for Intensity 7, exceeds 4 storeys for Intensity 8, the longitudinal bars of the tie-column should adopt 4φ14, and the spacing of stirrups shall not be larger than 200mm. For the tie-columns at the corners of the exterior seismic wall, the cross section and the reinforcement amount may be increased accordingly. 2
The connection of the tie-column and the adjacent block seismic wall shall be built into
horse-toothed joints, the adjacent block hole with the tie-column should be filled for Intensity 6, and shall be filled for Intensity 7, and shall be filled and dowel reinforcements for Intensity 8 and 9. The φ4 tie reinforcing fabric shall be installed in each 600mm along the height of the seismic wall, and they are arranged for 1/3 storeys on bottom at Intensity 6 and 7; 1/2 storeys on bottom at Intensity 8 and all storeys at Intensity 9. The spacing along seismic wall height shall not be larger than 400 mm. 3
At the connection of the tie-column and the ring-beam, the longitudinal bars of the
tie-column shall be arranged throughout the ring-beam to ensure the continuation of longitudinal bars in the tie-column. 4
The tie-columns may not establish individual footing, but they shall extend to 500mm into
the underground level, or shall connect with the foundation ring-beam, which buried depth less than 500mm underground. 7.4.4
The cast-in-situ ring-beam of small-block building shall be installed in accordance with the
requirements in the multi-storey masonry buildings ring-beam specifeid in Article 7.3.3, the width of the ring-beam shall not be less than 190mm, the reinforcement shall not be less than 4 φ12, and the spacing of stirrups shall not be larger than 200mm. 7.4.5
For the multi-storey small block building exceeds 5 storeys for Intensity 6, exceeds 4 storeys
for Intensity 7, exceeds 3 storeys for Intensity 8, horizontal reinforcing fabrics shall be installed at the intersection of the block seismic wall or the intersection of the core-column and the seismic wall, and The depth of section hereof shall not be less than 60mm, the longitudinal bars shall not be smaller than 2φ10, and with tie reinforcement; the concrete strength Grade shall not be lower than C20. For horizontal concrete in situ, the channel block may replace formwork, and longitudinal reinforcement and tie reinforcement may not be changed. 7.4.6
Category C multi-storey small block buildings, when the transverse seismic wall is less and
the total height and the number of storeys is close to or reaches the limits in Table 7.1.2, shall meet the requirements in Article 7.3.14 of this code; the tie column in seismic wall may be replaced by core column; and the quantity of pouring hole of core column shall not be less than 2. The diameter of the bar inserted into each hole shall not be less than 18mm. 7.4.7
Other seismic design details for multi-storey small-block buildings shall comply with relevant
requirements from Articles 7.3.5 to Article 7.3.13 of this chapter. The spacing of tie steel mat shall meet the related requirements of this code, and it shall be 600mm and 400mm.
7.5 7.5.1
Details of Seismic Design for Multi-storeys Buildings with Bottom-frame
The multi-storey brick structures above the framed storeys shall be installed with reinforced 82
concrete tie-columns and shall meet following requirements: 1
The location of the reinforce concrete tie-columns and core-column shall be installed
according to the provision in Article 7.3.1 and 7.4.1 of this code depending on the total storeys of the building. 2
Beside the requirements in Article 7.3.2, 7.4.2 and 7.4.3, the structure of tie-columnand core
column shall also meet the following requirements: 1)
The cross section of the tie-column shall not be less than 240mm×240mm (240 mm×
190 mm for seismic wall thickness 190mm). 2)
The longitudinal bars of the tie-column shall not be less than 4φ14, and the spacing of
stirrups shall not be larger than 200mm. The bars inserted into the each core column hole shall not be smaller than 1φ14, and the φ4 welded steel fabric shall be arranged every other 400mm between core columns along the seismic wall height. 3
The tie-column shall be connected with ring-beams in each storey, or shall be reliably tied
with the cast-in-situ slabs. 7.5.2
1
The structure of transition layer seismic wall shall meet the following requirements: The center line of upper masonry seismic wall should superpose with the one of bottom
frame beam and seismic structural wall; the tie column or core column should be penetrate frame column up and down. 2
For transition layer, tie column or core column shall be arranged on the position
corresponding to the tie columns of frame column, concrete seismic wall or restraining masonry seismic wall; the spacing of the tie columns in seismic wall should not be larger than the storey height; the core column shall be arranged according to the requirements of Table 7.4.1 and the maximum spacing should not be larger than 1m. 3
The longitudinal reinforcement of tie column in transition layer, at Intensity 6 and 7, should
not be less than 4φ16; at Intensity 8, it should not be less than 4 φ18. The longitudinal reinforcement of core column in transition layer, at Intensity 6 and 7, should not be less than 1 φ16; at Intensity 8, it should not be less than 1φ18 each hole. Generally, the longitudinal reinforcement shall be anchored into the lower frame column or concrete seismic wall; when the longitudinal reinforcement is anchored into the bressummer, the relevant position of the bressummer shall be reinforced. 4
The masonry seismic wall in transition layer, at windowsill elevation, shall be arranged
horizontal cast-in-situ reinforced concrete strip along full length of vertical and horizontal seismic wall; the depth of section hereof shall not be less than 60mm, and the width is not less than the seismic wall thickness. the longitudinal reinforcement is not less than 2 φ10, and the diameter of transverse distribution reinforcement with spacing not larger than 200mm is not less than 6mm.Furthermore, for the brick masonry seismic wall between adjacent tie columns, 2 φ6 horizontal reinforcement along full length and tie meshes made of φ4 short bars in plane spot welding or φ4spot welding reinforcing mat shall be arranged every 260mm along the seismic wall height; and the mats shall be anchored into tie column; φ4 horizontal spot welding reinforcing mat along full length shall be arranged between core columns for small block masonry seismic wall along the seismic wall height . 5
On masonry seismic wall in transition layer, tie column or simple pore core column with the 83
section area not less than 120mm× 240mm (120mm×190mm if the seismic wall thickness is 190mm) should be arranged on both side of the opening - door opening with width not less than 1.2m and window opening with width not less than 2.1m. 6
When the masonry seismic wall in transition layer is not aligned at the bottom frame beam or
seismic wall, seismic wall-bearing transition beam shall be arranged in bottom frames, and the reinforcement measures higher than Item 4 shall be taken for the brick seismic wall or block seismic wall in transition layer. 7.5.3
When the bottom of bottom Frame-seismic wall masonry building adopts reinforced concrete
seismic wall, the section and structure of the seismic wall shall meet the following requirements: 1
In the perimeter of the seismic wall panel, a boundary frame formed by beams (or hidden
beams) and side-columns (or frame column) shall be installed. The cross section width of the side beams should not be less than 1.5 times of the seismic wall panel thickness, the cross-sectional height should not be less than 2.5 times of the seismic wall panel thickness. The cross-sectional height of the end-column should not be less than 2 times of the seismic wall panel thickness. 2
The thickness of the seismic wall panel should not be less than 160mm, and shall not be less
than 1/20 of the clear height of the seismic wall panel. The seismic wall should be installed openings to form several short seismic wall-segments, and the height-width ratio of each seismic wall-segment should not be less than 2. 3
The reinforcement ratio for both vertical and horizontal distributed reinforcements of the
seismic wall shall not be less than 0.30%, which shall be arranged in two layers. The spacing of tie bars for two layers shall not be larger than 600mm, and the diameter of the tie bar shall not be less than 6mm. 4
The boundary elements of the seismic wall may be installed according to the requirements for
general portions in Section 6.4 of this code. 7.5.4
When restraining brick masonry seismic wall is adopted for the bottom storey of bottom
Frame-seismic wall brickwork at Intensity 6, the structure hereof shall meet the following requirements: 1
The thickness of brick seismic wall shall not be less than 240mm, the strength of the mortar
used shall not be lower than M10, and the seismic wall shall be built first and then cast the frame. 2
The horizontal reinforcement of 2φ8 and tie meshes made of φ4 short bars by plane spot
welding shall be arranged in each 300mm along the frame columns, and shall be installed along overall length of the brick seismic wall; the reinforced concrete horizontal tie beam connected with frame column shall be arranged on half height of the seismic wall. 3
When the length of seismic wall is larger than 4m and on both sides of the opening, added
tie-column shall be installed within the seismic wall. 7.5.5
When restraining brick masonry seismic wall is adopted for the bottom storey of bottom
Frame-seismic wall concrete block buildings at Intensity 6, the structure hereof shall meet the following requirements: 1
The seismic wall thickness shall not be less than 190 mm, the strength Grade of bonding
mortar shall not be less than Mb10 and the frames shall be casted after seismic wall bricking. 84
2
The 2φ9 horizontal reinforcement along full length and tie meshes made of φ4 short bars in
plane spot welding shall be arranged every 400mm along frame columns,and they are arranged horizontally along full length of block seismic wall; the reinforced concrete horizontal tie beam connected with frame column shall be arranged on half height of the seismic wall. The tie beam section shall not be less than 190 mm×190 mm, the longitudinal reinforcement shall not be less than 4φ12; the hoop diameter shall not be less than φ6 and the hoop spacing shall not be greater than 200 mm. 3
Core columns shall be arranged on both sides of door and window opening, added core
columns shall be arranged in seismic wall when the seismic wall length is larger than 4m, and the core column shall meet the relevant provisions in Article 7.4.2; on other positions, reinforced concrete tie column should be used to replace core column, and the reinforced concrete tie column shall meet the relevant provisions of Article 7.4.3. 7.5.6
The frame column for masonry building with bottom Frame-seismic wall shall meet the
following requirements: 1
The column section shall not be less than 400 mm×400 mm; the column diameter shall not be
less than 450 mm. 2
The axial force ratio of the column, at Intensity 6, should not be larger than 0.85; at Intensity
7, it should not be larger than 0.75; at Intensity 8, it should not be larger than 0.65. 3
The total minimum reinforcement ratio of the longitudinal reinforcement for columns, when
the bar strength standard value is lower than 400MPa, for central column at Intensity 6 and 7, shall not be less than 0.9; at Intensity 8, it shall not be less than 1.1%; for side column, corner column and concrete seismic wall end column at Intensity 6 and 7, it shall not be less than 1.0%; at Intensity 8, it shall not be less than 1.2%. 4
The diameter of hoops for column, at Intensity 6 and 7, shall not be less than 8mm; at
Intensity 8, it shall not be less than 10mm, and the hoops shall be densed at total height with the spacing not larger than 100mm. 5
The combined bending moment design value of the upper and lower ends of the column
shall be multiplied by the enhancement coefficient, and the enhancement coefficient of Grade 1, 2 and 3 shall be respectively 1.5, 1.25 and 1.15. 7.5.7
The roof for masonry building with bottom Frame-seismic wall shall meet the following
requirements: 1
The base slab for transition layer shall adopt cast-in-situ reinforced concrete slab. The slab
thickness shall not be less than 120mm; less or smaller opening shall be opened. When the opening size is larger than 800mm, edge beam shall be arranged at periphery of the opening. 2
On other storeys, the cast-in-situ ring-beam shall be used when adopting fabricated reinforced
concrete floor slab; when cast-in-itu reinforced concrete is adopted, additional ring-beam may not be used. But the reinforcement of the floor-slab along the seismic structural wall periphery shall be improved and connected stably with corresponding tie column. 7.5.8
As for reinforced concrete bressummer for masonry building with bottom Frame-seismic wall,
the section and structure of the seismic wall shall meet the following requirements: 85
1
The sectional width shall not be less than 300mm. and the depth of section shall not be less
than 1/10 the span. 2
The hoop diameter shall not be less than 8mm and the spacing shall not be
200mm; the stirrup spacing shall not be
greater than
greater than 100mm in following arranges: within the range
at 1.5 times beam depth at beam end less than 1/5 beam clear span; opening of upper seismic wall; and respective 500 mm on both sides of the opening and not less than the beam depth. the stirrup spacing shall not be 3
greater than 100mm.
The waist reinforcement shall be arranged along the beam depth, the quantity shall not be less
than 2φ4, and the spacing shall not be greater than 200mm. 4
The longitudinal bearing steel bar and waist reinforcement of beam shall be anchored in
columns in accordance with the requirements of tension reinforcement. The anchorage length, in column, of the longitudinal reinforcement on support shall meet the relevant requirements on concrete frame-support beam. 7.5.9
The strength Grade of the materials used for multi-storey masonry buildings with
bottom-frame shall meet the following requirements: 1
The concrete strength Grade of the frame column, seismic wall and spandrel girder shall not
be lower than C30 2
The mortar strength Grade for masonry seismic wall of transitional storey (layer) shall not be
lower than MU 10, the one of brick masonry bonding mortar shall not be lower than Mb10, and the one of the block masonry bonding mortar shall not be lower than Mb10. 7.5.10
Other aseismic structural measures for bottom Frame-seismic wall masonry building shall
comply with the requirements of Section 7.3 and 7.4 and Chapter 6 of this code.
8
Multi-storey and Tall Steel Structural Buildings 8.1
8.1.1
General Requirements
The provisions of this chapter shall be applied to the structural type and maximum height of
steel structural civil buildings stipulated in Table 8.1.1. For structures assigned to irregular plane and elevation or structures, the applicable maximum height shall be reduced accordingly. Notes: 1
The seismic design of steel support –concrete frame and steel support –concrete tube shall meet the
requirements in Appendix G of this code 2
The seismic design of multi-storey steel structural factory shall meet the requirements in Section H.2 in Appendix
H of this code. Table 8.1.1 Applicable Ma ximum Height of Steel Structural Building (in m) Intensity 6, 7
Intensity 8
Intensity
Intensity
Type of structures (0.10g) Frame
110
7(0.15g)
90
(0.20g)
(0.30g)
(0.40g)
90
70
50
86
Frame-epicenter brace
220
200
180
150
120
Frames-eccentric brace (tensile seismic wallboard )
240
220
200
180
160
300
280
260
240
180
Tube (framed tube, tube by tube, truss tube, tubes) and mega frame Notes: 1 T he height of building refers to the height from the outdoor ground level to the main roof level of a building (which locations exceeding the roof level are not included); 2
When the height of a building exceeding that as provisions in this Table, special researches and demonstration shall be carried out
and effective seismic measures shall be taken. 3
8.1.2
The tubes in the table do not include concrete tubes.
The maximum height-to-width ratio of steel structural civil buildings applicable to this chapter
should not exceed the limits in Table 8.1.2. Table 8.1.2 Maximum Height-to-width Ratios of Steel Structural Civil Building Intensity
6, 7
8
9
Maximum height-to-width ratio
6.5
6.0
5.5
Note: The height for calculating the height-to-width ratio shall be counted from the ground level.
8.1.3
The seismic design of steel structural buildings shall adopt different seismic Grades, based on
the precautionary categories, Intensity, and the height of the buildings, and in accordance with the corresponding calculation and the structural requirements. The seismic Grade of Categoty C buildings should be determined according to Table 8.1.3. Table 8.1.3
Seismic Grades of Steel Structural Buildings Intensity
Height of the buildings 6 ≤50m
>50m
Notes: 1
4
7
8
9
4
3
2
3
2
1
When the height approaches or equal to the height dividing line, it should be allowed to determine seismic
Grade based on the degree of irregularity of the house, the sites and the foundation condition. 2
In general, the seismic Grade of the components should be the same with the structure; When the bearing
capacity of each component in some part meets the requirement of 2 times earthquake-action-combination internal force, the 7~9 Intensity components should be allowed to determined by lowering one Grade.
8.1.4
When seismic joints need to be installed, the minimum clear width of the seismic joint shall
not be less than 1.5 times of that for reinforced concrete buildings. 8.1.5
Grade 1 and 2 steel structural buildings should use eccentric braced, reinforced concrete
seismic wall plane with vertical separators, reinforced concrete seismic wall plane with embedded steel brace or other energy-dissipating braces or tube structures. When adopt framed structures, Category A and B and high-rise Category C buildingss should not 87
adopt single-span frames, while Category C multi-storey buildings should not adopt single span frames. Note: Grade 1, 2, 3 and 4 in this chapter are short for seismic Grade 1, 2, 3 and 4 respectively.
8.1.6
1
The steel frame-braced structures shall meet the following provisions: The arrangement of the braced frame shall be basically symmetrical in two directions; the
length-to-width ratio of the floor between two adjacent braced frames should not be larger than 3. 2
The Grade 3 and 4 structures with not exceeding 50m height should adopt epicenter brace,
eccentric brace or flexion restriction brace and other kinds of energy dissipation brace. 3
Eccentric braced frame should adopt X-shape brace, inverted-V shape brace or single
diagonal brace; should not adopt K-shape brace. The axis of braces should be intersected on the convergence with the axis of the beam column component; in case of deviation, the eccentricity from the convergence shall not exceed the width of the support bar, and the additional bending moment due to this shall be counted. When epicenter braced frames adopt pulling-only single diagonal system, two groups of different dip direction diagonal brace should be installed, and the difference of the projecting areas, at the horizontal direction, of the section of the single diagonal braces (at different directrions) in groups shall not be larger than 10%. 4
Each brace of the eccentric braced frame shall have at least one end connecting with the
framed beam, and thus form an energy-dissipating beam-segment that length is from the brace-to-beam connection to the beam-to-column joint or is between both brace-to-beam connections within the same span. 5
When adopt flexion restriction braces, inverted-V shape braces and twin layout single
diagonal braces should be adopted, and no K-shape or X-shape braces should be adopted. The included angle between brace and column should be between 35 °~55°. When flexion restriction brace is depressed, the sum of its design parameter and performance check as a kind of energy dissipation nodal calculation method can be designed according to relevant requirements. 8.1.7
For steel frame -tube structures, a reinforcement layer which is consist of tube outrigger
trusses or outrigger trusses and perimeter trusses may be installed if necessary. 8.1.8
1
Roofs of steel structural building shall meet the following requirements: Profiled steel sheet cast-in-situ reinforced concrete composite floor or reinforced concrete
floor plank should be adopted, and reliable connection with steel beams is needed. 2
For the steel structures with 6 and 7 Intensity and do not exceed 50m height, fabricated
integral type reinforced concrete floor plank may be used, as well as fabricated floor-slab or other light type floors .But floor-slab embedded parts should be welding with steel beams ,or adopt some other measures that can guarantee the integrity of the floor . 3
For the situation such as switching the floor or there is a big hole on the floor-slab ,a
horizontal brace may be installed if necessary . 8.1.9
1
The basement arrangement of steel structural building shall meet the following requirements: When basement is installed for the steel frame-brace (or seismic wall) structures, the vertical
continuously arranged brace or seismic wall shall extend to the foundation, and the frame column 88
shall least extend to the first floor underground. 2
Its embedded depth of foundation should not be less than 1/15 of the total building height
when adopting natural subsoil; the buried depth of platform on piles should not be less than 1/20 of the total building height when adopt pile foundation.
8.2 8.2.1
Essentials in Calculation
Steel structures shall adjust the seismic effect according to the provisions of this code, and the
storey drift shall meet the relevant requirements in Section 5.5 of this code. To do the seismic check of component section and connection, the non-seismic design value for the bearing capacity of components shall be divided by the specified seismic adjustment factors for bearing capacity of components in this code. If no provisions in this chapter, the seismic checking of the components and its connections shall be made in accordance with current codes for relevant structure design 8.2.2
The damping ratio of the steel structure seismic calculation should meet the following
provisions: 1
In the calculation under frequent earthquake, when the height is not larger than 50m, 0.04
should be taken; 0.03 may be taken for height larger than 50m; 0.02 may be taken for height no less than 50m. 2
When the seismic overturning moment of the eccentric brace frames is 50% larger than the
total seismic overturning moment, additional 0.005 can be added to the damping ratio corresponding to Item 1. 3 8.2.3
In the elastic-plastic analysis under rare earthquake, 0.05 damping ratio is preferred. Steel structure's internal force and deformation analysis under earthquake action shall meet the
following provisions : 1
Steel structure shall calculate people gravity of the second-order effect in accordance with
Article 3.6.3 of this code. Adding hypothetical horizontal force on each column top in accordance with current national standard “ Code for Design of Steel Structures “GB 50017 when subject to the elasticity analysis of the second-order effect. 2
Frame beam can be designed according to cross sectional internal force of the beam end. For
I section column, the influence of shear deformation for beam-to-column connection panel zone has on the structure's displacement should be calculated. For box column frames, Epicenter braced frames and under 50m steel structures, their inter-storey displacement calculation can be left out of the influence on shear deformation for beam-to-column connection panel zone 3
The diagonal rod of the steel structural frame -supporting structure can be calculated by the
hinge bar on the end; The earthquake storey shear force, The frame part which is calculated by rigidity distribution, shall multiplied by adjustment coefficient, reach a smaller value which is not less than 25% of the structure bottom board's total earthquake storey shear force and the frame part's calculation 1.8 times of the maximum storey shear force 4
When the eccentricity between the epicenter brace axial line and intersection joint of the
beam and column axial lines does not exceed the width of the brace component, the analysis may be done assumed to epicenter brace frame; but the added bending moment caused by which shall be 89
taken into consideration. 5
For the eccentric brace frame structures, the interior force design value of components shall
be adjusted according to the following requirements: 1)
The axial force design value of the brace component shall be taken as the product of the
brace axial force that correspond to the shear bearing capacity of the connecting energy-dissipating beam-segment and the enhancement coefficient. This coefficient, shall not be less than 1.4 for Grade 1, not less than 1.3 for Grade 2, and not less than 1.2 for Grade 3; 2)
The interior force design value of frame beam locating at the energy-dissipating
beam-segment shall be taken as the product of the frame beam interior force and the enhancement coefficient. This coefficient value shall not be less than 1.3 for Grade 1, not be less than 1.2 for Grade 2and not less than 1.1 for Grade 3 3)
The interior force design value of the frame column shall be taken as the product of
column interior force that correspond to the shear bearing capacity of the connecting energy-dissipating beam-segment and the enhancement coefficient. This coefficient value shall not be less than 1.3 for Grade 1, not less than 1.2 for Grade 2, not less than1.1 for Grade 3. 6
The calculation of the reinforced concrete seismic wall plane with embedded steel brace and
the reinforced concrete seismic wall plane with vertical separators shall be carried out according to relevant provisions. The reinforced concrete seismic wall plane with vertical separators may only resist the shear caused by horizontal load, but not bearing the vertical load. 7
The seismic interior force of frame columns supporting the transfer components of the steel
structure shall be multiplied by the enhancement coefficient, this value may be taken as 1.5. 8.2.4
When the upper flange of the steel frame beam with shear-connectors such as shear-stubs is
connected to composite floor slab, the checking of integral stability of beams under seismic action may be omitted. 8.2.5
The seismic capacity checking of the steel frame components and connections shall meet the
following requirements: 1
In addition to the following conditions, the plastic capacity for the right and left ends of beam
and the upper and lower ends of the column at the joint shall meet the requirements of following equa-tion: 1)
The shear bearing capacity of the storey where column is located is greater than 25% of
that of the adjacent upper storey; 2)
Column axial force ratio is not greater than 0.4 or N2 ≤
Ac f (N2 is the designed
combination axial force under 2 times the earthquake action); 3)
Node connected with supporting diagonal rod
Uniform section beam Σ W pc ( f ye- N / A) ≥ηΣ W pb f yb
(8.2.5-1) 90
Beam with variable section at end flange
∑W
pc
( f yc－ N/A c ≥
∑η W
f + V pb s
pb1 yb
(8.2.5-2)
Where W pc, W pb ——The plastic section modulus of the column and beam separately;
W pb1 ——Plastic section modulus of the beam, in the section of which plastic hinge positions; f yc, f yb ——The specified steel yield strength of the column and the beam separately;
N ——The axial force design value of the column; Ac ——The cross-sectional area of the column; η ——The strong-column enhancement coefficient, which is taken as 1.15 for Grade 1, 1.10 for Grade 2 and 1.05 for Grade 3;
V pb ——Beam plastic-hinge shear force; s——Distance from plastic hinge to column surface, when plastic hinge may be the
minimum
part of variable cross section flange at beam end 2
The yield capacity for the joint-panel shall meet the requirements of the following formula: ψ ( M pb1+ M pb2)/V p≤(4/3) f v
(8.2.5-2)
For I-shaped section column V p=h bhct w
(8.2.5-3)
For box-shaped section column V p=1.8h bhct w
(8.2.5-4)
V p = (π / 2)hb1hc1t w
(8.2.5-6)
For round-pipe section column
3
The joint-panel of I-shaped and box-section column shall be checked according to the
following formulae: t w≥(h b+hc)/90 ( M b1+ M b2)/V p≤(4/3) f v/γRE
(8.2.5-7) (8.2.5-8)
Where M pb1, M pb2 ——The full plastic bending capacity of the beam on the both sides of the joint-panel; V p ——Volume of the joint-panel; 91
f v ——The design value of specified steel shear strength; ψ ——Deducting factor, which is taken as 0.6 for Grade 3 and 4 and 0.7 for Grade 1 and 2; h b, hc ——The distance between the middle points of beam flange depth and the distance between the middle points of column flange depth separately; t w ——The web thickness of joint-panel of the column; M bl, M b2 ——The bending moment design value of the beams at the two sides of the joint-panel; γRE ——The seismic adjustment factor of joint-panel bearing capacity, taken as 0.75. 8.2.6
The seismic capacity check of the epicenter braced frame component shall meet the following
requirements: 1
The compressive capacity of the braced component shall be checked according to the
following formulae: N /(φ A br )≤ψ f /γRE
(8.2.6-1)
ψ =1/(1+0.35λ n)
(8.2.6-2)
f ay / E
(8.2.6-3)
6λ n=(λ /π) Where
N ——Axial force design value of the braced component; A br ——Cross-sectional area of the braced component; φ ——Stability factor of the axis compressive component; ψ ——Strength reducing factor under cycling load; λ , λ n ——The normal slenderness ratio of the braced component; E ——Elastic modulus of the braced component; f, f ay ——The specified steel yield strength of the braced component; γRE ——The seismic adjustment factor of brace bearing capacity. 2
The frame beam of inverted-V shape and the V-shaped brace shall keep con-tinuous at the
connection joint of the brace. Gravity load and the bearing capacity under unbalanced force action during brace flexion shall be checked according to the beam for which brace supporting point action is not counted; unbalanced force shall be calculated according to 0.3 times the minimum yielding bearing capacity of in-tension brace and 0.3 times the maximum flexion bearing capacity of compression brace. If necessary, inverted-V shaped and V-shaped brace may be arranged alternatively along vertical direction or zipper column shall be adopted. Note: The beams of the top storey and the penthouse may not follow the provisions in this item.
8.2.7
The seismic capacity check of the eccentric braced frame components shall meet the following
requirements: 1
The shear capacity for the energy-dissipating beam-segment of eccentric braced frame shall 92
be checked according to the following formulae: When N≤0.15A f V ≤φV l /γRE V l =0.58Aw f ay
or
(8.2.7-1)
V l =2 M l p /a, taken as the smaller value Aw=(h-2t f )t w M l p =W p f
When N >0.15 Af V ≤φV l c/γRE
(8.2.7-2)
V l c=0.58 Aw f ay 1 − [ N /( Af )]2 Or
V l c=2.4 M l p [1-N/(A f )]/a, taken as the smaller value
Where V , N ——The shear force design value and the axial force design value of the energy-dissipating beam-segment separately; V l , V l c ——The shear capacity and that with axial force affection of the energy-dissipating beam-segment separately; M l p ——Full plastic bending capacity of the energy-dissipating beam-segment; A, Aw ——The total sectional area and web sectional area of the energy-dissipating beam-segment separately; W p ——Plastic section modulus of the energy-dissipating beam-segment;
a, h —— Net length and profile height of energy-dissipating beam segment respectively; t w , t f ——Web thickness and flange thickness of energy-dissipating beam segment respectively; f , f ay ——The tensile strength design value and the specified yield strength of the energy-dissipating beam-segment separately; φ ——Calculation factor, taken as 0.9; γRE ——The seismic adjustment factor of capacity of the energy-dissipating beam-segment, taken as 0.75. 2
The bearing capacity of the connection between the brace and the energy-dissipating
beam-segment shall not be less than the bearing capacity of the brace. If the brace bears the bending moment, the connection of the brace and beam shall be designed as pressure and bending resisting connection. 8.2.8
Connection calculation for the lateral-force-resisting components of steel structures shall meet
the following requirements: 93
1
Bearing capacity designed for lateral-force-resisting component connection of steel structure
shall not be less than the one designed for the connected component; in addition, high strength bolt connection shall be free from sliding. 2
The ultimate bearing resistance for the connection of lateral-force-resisting component of
steel structure shall be greater than the yielding bearing capacity of the connected component. 3
Ultimate bearing resistance for the rigidly connection of beam and column shall be checked
according to the following formulae:
M u j ≥η j M p
(8.2.8-1)
M u j ≥ 1.2( 2 M p / l n ) + V Gb 4
(8.2.8-2)
Ultimate bearing resistance for the connection of brace and frame and for the splicing of
beam, column and brace shall be checked according to the following formulae: Connection and splicing for brace
N jubr ≥η j Abr f v
(8.2.8-3)
Beam splicing
j M ub , sp ≥ η j M p
(8.2.8-4)
Column splicing
j M ub , sp ≥ η j M pc
(8.2.8-5)
5
Ultimate bearing resistance for the connection of column base and foundation shall be
checked according to the following formula:
M u j,base ≥ η j M pc
(8.2.8-6)
Where,
M p , M pc —— Plastic bending bearing capacity of beam and plastic bending bearing capacity of column when axial force is considered respectively;
V Gb ——The designed shear force of beam-end section being analyzed according to simple-supported beam when beam is under the action of gravity representative load value (for Intensity 9, the representative load of tall building shall include standard vertical-earthquake-action value);
l n ——Clear span of beam; Abr ——Sectional area of supporting bar; M u j、V u j ——Ultimate bending and shear capacity of connection respectively; 94
j j j N ubr 、 M ub , sp、M uc , sp ——Ultimate compression (tension) and bending capacity of brace
connection and splicing as well as the s plicing of beam and column;
M u j,base ——Ultimate bending capacity of column base
η j ——Connection coefficient, which may be adopted according to Table 8.2.8 Table 8.2.8:
Connection Coefficients for the Seismic Design of Steel Structures Brace connection and
component
Beam column connection splicing
Base material
Column base designation
Bolted Welding
Welding
Bolted connection
connection Q235
1.40
1.45
1.25
1.30
Embedded
1.2
Q345
1.30
1.35
1.20
1.25
Epibolic
1.2
Q345GJ
1.25
1.30
1.15
1.20
Exposed
1.1
Notes:
1 Steels with the yield strength being greater than Q345 shall be adopted according to provisions on Q345;
2
GJ steels with the yield strength being greater than Q345GJ shall be adopted according to provisions on Q345GJ;
3
When welding web plate at flange is bolted, the connection coefficients are applied according to the connection
type listed in the above table respectively.
8.3
Details of Seismic Design for Steel Framed Structures
The slenderness ratio of frame columns, at Grade 1, shall not be larger than 60
8.3.1
235 / f ay ; at
Grade 2, it shall not be larger than 80 235 / f ay ; at Grade 3, it shall not be larger than 100 235 / f ay ; at Grade 4, it shall not be larger than 120
235 / f ay .
The width-to-thickness ratio of the elements of beam and column shall meet the requirements
8.3.2
in Table 8.3.2: Table
8.3.2
Name of the element
Column
Width-to-thickness Ratios of the Elements of Beam and Column Grade 1
Grade 2
Grade 3
Grade 4
Flanges of I-shaped
10
11
12
13
Plates of box-section
43
45
48
52
Web of I-shaped
33
36
38
40
95
Flanges of I-shaped or plates projecting from
9
9
10
11
30
30
32
36
box-section Flanges between both Beam
webs of box-section
Webs of I-shaped or
72—120 N b
/( Af )
72—100 N b
/( Af )
80—110 N b
/( Af )
85—120 N b
/( Af )
box-section: ≤60
Notes: 1
≤65
≤70
≤75
The values listed in the table is applicable to Q235 steel, other steel types shall be multiply with
235 / f ay .
2
8.3.3
N b /( Af )
is the axial force ratio of a beam.
Lateral brace of beam and column components shall meet the following requirements:
1
Lateral brace shall be arranged for the compression flange of beam column component.
2
Lateral braces shall be arranged for beam column component on the section with plastic
hinge and upper and lower flange. 3
The slenderness ratio of the component between both adjacent lateral braced points shall
comply with relevant provisions of the current national standard “Code for Design of Steel Structures” GB 50017. 8.3.4
The details of connection of the beam and the column shall meet the following requirements:
1
The connection of the beam and the column should adopt the form of continue column.
2
When a column is connected to beams by rigid connection at two orthogonal directions, the
box section columns should be adopted, and partition plate shall be arranged on the connection of beam flange; when the partition plate adopts slag welding, the column seismic wall plate thickness should not be less than 16mm; otherwise, I-shaped column or penetrating partition plate shall be used. When the columns adopt rigid con-nection with the beam only one direction, the I-shaped columns should be adopted, and the column web shall be placed within the rigid connection plane of the frame. 3
When the I-shaped and box-section columns adopt rigid connection with the beam, the
following requirements shall be observed (Figure8.3.4-1):.
96
Figure
1) flange;
8.3.4-1
On-site Connections of Frame Beam and Column
The fusion groove weld shall be adopted between the beam flange and the column
at Grade 1 and 2, the shock-tenacity of the V-weld joint shall be checked, and its Charpy
shock-tenacity shall not be lower than 27J at -20℃; 2)
When horizontal stiffening ribs are used in the column at the corresponding locations of
the beam flanges, the thickness of the stiffening ribs shall not be less than the thickness of the beam flanges; the Intensity of the stiffening ribs shall be the same as the Intensity of the beam flange. 3)
The web of the beam should adopt friction-type high-tensile bolt to connect with the
column through gusset plates (gas shielded welding may be adopted when it can ensure the field welding quality by process inspection). Web plate corner shall be arranged with welding holes, and the hole shape shall completely separate the web plate end from full penetration groove weld between beam flange and column flange. 4)
The welding for web plate connecting plate and column, when the web plate thickness
is not larger than 16mm, shall adopt twin fillet weld, and the effective weld thickness shall meet the equal strength requirements and shall not be less than 5mm; when the plate thickness is larger than 16mm, groove K butt weld shall be adopted. The welded joint should adopt gas shielded welding and the plate end shall be welded in contour. 5)
At Grade 1 and 2, tip enlarged connection, beam end combined with cover plate or
bone connection that can shift the plastic hinge from beam end out should be adopted. 4
When the frame column adopts rigid connection with the cantilever beam segment
(Figure8.3.4-2), the cantilever beam segment and the column shall be connected with fusion weld at facilities, and at in-situ, the beam may connection by using flange welding and web bolts ( a) or completely connected by bolts (b).
Figure
5
8.3.4-2
Connections of the Frame Beam and Column Through Suspending Beam
For the box-section column, the separator shall be installed in corresponding location of the
beam flange and the connection with plates of column shall adopt fusion butt-weld. For the I-shaped section column, the connection of the horizontal stiffening ribs with the flange of column shall adopt fusion butt-weld, and connection with the web of column may adopt fillet weld. 8.3.5
When the volume of the joint-panel cannot satisfy that the provisions in Clause 2 and 3 of
Article 8.2.5, the thickness of joint-panel shall be increased or add-stiffening plate shall be welded. The thickness of the add-stiffening plate and the welding joint shall be designed according to the requirements for transferring the shear-force-resistant of add-stiffening plat. 8.3.6
When the beam and the column adopt rigid connections, within the range of 500mm in the
upper and lower of flanges of beam, the welding joints between the flanges and the webs of I-shaped 97
column and between the plates of box-section column shall use the fusion V-weld. 8.3.7
The distance from the frame column joint to the frame beam top may be the smaller one of 1.3
m and the half column clear height. The splice of the upper and lower columns shall adopt completely fusion weld joints. Within the range of 100mm in the splice of the upper and lower part of the column, the welding joints between the flanges and the web of I-shaped column and between the corner plates of box-section column shall adopt the completely fusion weld. 8.3.8
The rigid connection column foots of steel structures should adopt the buried or external
enclosed type foots; for Intensity 6 and 7, and not exceeding 50mm, exposed foots may also be used.
8.4 8.4.1
Details of Seismic Design for Steel Frame-concentrically-braced Structures
The limits of the slenderness ratio of the component bar for center brace and the
width-to-thickness ratio of plate piece shall meet the following requirements: 1
The slenderness ratio of brace strut, as compression component, shall not be greater than
120 235 / f ay ; tie bar component must not be used for center brace at Grade 1, 2 and 3; when tie bar is used for Grade 4 brace, the slenderness ratio hereof shall not be greater than 180. 2
The width-to-thickness ratio of plate piece for brace strut shall not be greater than the limits
listed in Table 8.4.1. When gusset plate connection is adopted, the strength and stability of gusset plate shall be considered. Table
8.4.1
Width-to-thickness Ratio Limit of Center Brace Plate in Steel Structure
Name of element
Grade 1
Grade 2
Grade 3
Grade 4
Overhung part of flange
8
9
10
13
Web plate with I-shaped section
25
26
27
33
Seismic wall plate with box section
18
20
25
30
38
40
40
42
Ratio Circular pipe External diameter to seismic wall thickness
Note: the values listed in the table are applicable to steel Q235. For steels with other designation shall be multiplied
235 / f ay
with
8.4.2
1
; for circular pipe, they shall be multiplied with
235 / f ay .
The structure of center brace joints shall meet the following requirements: At Grade 1, 2 and 3, the brace struts (support) should be made using the rolled H-shaped
steels, its two ends and the frame may use rigid connection, and the connection part of the beam and column with the brace shall install stiffener ribs; when H-shaped steels are used at Grade 1 and 2, the connection of flange and web should adopt full penetration continuous weld. 2
At the location of connection between the brace and the frame, the diagonal ends should be
made into arc shape; 98
3
At the intersecting place of beam with the inverted-V and V-shaped braces, lateral braces
shall be installed. And the lateral slenderness ratio (λ y) of beam segment from the laterally braced point to the supporting of the beam and its bearing capacity shall comply with the provisions in the national standard “Code for Design of Steel Structures” GB 50017; 4
If the brace and frames are connected with gusset plates, the connection shall meet the
provision of the current national standard “Code for Design of Steel Structures” GB 50017 about “the gusset plate has an angel not less than 30° on each side of the connection component”; the distance from the brace end to the closest partial fixing point (end of the attachment weld of gusset plate and framing component) along the brace bar component shall not be less than 2 times the gusset plate thickness. 8.4.3
When the epicenter brace frame, which height does not exceed 100m and the seismic-forces
distributed to the frame part is not larger than 25% of the total seismic shear, Aseismic structural details of Grade 1, 2 and 3 may be adopted according to the corresponding requirements that reducing one degree by the frame structure.
Other details shall comply with the provisions for framed
structures in Section 8.3 of this code.
8.5 8.5.1
Details of Seismic Design for Steel Frame-eccentrically-braced Structures
The specified yield strength of the steel material in the eccentric braced frame
energy-dissipating beam-segment shall not be larger than 345MPa. For the energy-dissipating beam-segment and other beam segment for the same span, the width-to-thickness ratio of the elements shall not be larger than the limit values in Table 8.5.1. Table
8.5.1
Limit Values for Width-to-thickness Ratio
Name of element
Width-thickness ratio
Flanges with one free edge
8
N /( Af )<0.14
90[1-1.65 N /( Af )]
Webs N /( Af )≥0.14
33[2.3- N /( Af )]
Note: The values listed in the table is applicable to Q235 steel, other steel types shall multiply with
235 / f ay ,
N /( Af )
is
the axial force ratio of a beam.
8.5.2
The slenderness ratio of the brace in eccentric brace frame shall not be larger than 120
235 / f ay , and the width-thickness ratio of the element shall not exceed the limit value of width-to-thickness ratio for components subject to axial compression through the centroidal axis at elastic design, which provisions in the national standard “Code for Design of Steel Structures” GB 50017. 8.5.3
1
The detail of the energy-dissipating beam-segment shall meet the following requirements: When N >0.16 Af , the length of the energy-dissipating beam-segment shall meet the following
requirements: 99
When ρ( Aw/ A)<0.3,
a<1.6 M l p /V l
(8.5.3-1)
When ρ( Aw/ A)≥0.3,
a≤[1.15-0.5ρ( Aw/ A)]1.6 M l p /V l
(8.5.3-2) ρ= N /V
(8.5.3-3)
Where, a ——The length of the energy-dissipating beam-segment; ρ ——The ratio of axial force design value to the shear force design value for the energy-dissipating beam-segment. 2
The add-stiffening plate welded to increase the thickness or opening shall not be arranged on
the web of the energy-dissipating beam-portion. 3
At the connection of the energy-dissipating beam-segment and the brace, stiffening ribs shall
be installed on the two sides of the web, the depth of the stiffening ribs shall be the same as that of the beam. The width of the stiffening ribs on one side shall not be s maller than (b f /2-tw), and the thickness shall not be smaller than 0.75t w and 10mm, whichever is bigger. 4
On the web of the energy-dissipating beam-segment, the intermediate stiffening ribs shall be
installed according to the following requirements: 1)
When a≤1.6 M l p /V l , the spacing of the stiffening ribs shall not be larger than (30t w-h/5);
2)
When 2.6 M l p /V l
the energy-dissipating beam-segment, and the spacing of the stiffening ribs shall not be larger than (52t w — h/5); 3)
When 1.6 M l p /V l
between the two cases above; 4) 5)
When a>5 M l p /V l , stiffening ribs may not be installed; The intermediate stiffening ribs shall be the same depth as the web of the
energy-dissipating beam-segment; when the depth of the energy-dissipating beam-segment is not larger than 640mm, the stiffening ribs may be installed at only one-sided of web; when the depth of the energy-dissipating beam-segment is larger than 640mm, stiffening ribs shall be installed at the both sides of the web; the width of the stiffening rib installing at only one-side shall not be less than (bf /2-t w) , and the thickness shall not be less than t w and 10mm. 8.5.4
The connection of the energy-dissipating beam-segment with the column shall meet the
following requirements: 1
When the energy-dissipating beam-segment connects with the column, its length shall not be
larger than 1.6 M l p /V l , and shall also comply with the provision related. 2
The connection between the energy-dissipating beam-segment flange and the column flange
shall adopt the completely fusion V-weld joint, the connection between energy-dissipating beam-segment web and the column shall adopt the fillet-welding joints (gas shielded welding). And the bearing capacity of the fillet-welding joint shall not be less than the axial tensile capacity, the shear capacity and the bending capacity of the web of the energy-dissipating beam-segment. 3
When the energy-dissipating beam-segment connected with the column web, completely 100
fusion V-weld joint shall be adopted for connection between the flange of the energy-dissipating beam-segment and the gusset plates; the fillet-welding joint shall be adopted for connection between the web of beam-segment and the column. The bearing capacity of the fillet joint shall not be less than the axial tensile capacity, the shear capacity and the flexure capacity for the web of the energy-dissipating beam-segment. 8.5.5
Laterally braces shall be installed on the upper and lower flange for ends of the
energy-dissipating beam-segment. The axial force design value of the laterally brace shall not be less than 6% of the axial tensile capacity design value of the flange of the energy-dissipating beam-segment, i.e. 0.06 bf t f f . 8.5.6
Laterally braces shall be installed on the upper and lower flange of the non-energy-dissipating
beam-segment of the eccentric brace framed beam, the axial force design of the laterally brace shall not be less than 2% for the axial tensile capacity of the beam flange, i. e. 0.02 bf t f f . 8.5.7
For the frame-eccentric-brace structures, when the height does not exceed 100m and the
seismic-forces distributed to the frame part is not larger than 25% of the total seismic shear, the requirements for detail requirements of frame part at Grade 1, 2 and 3 may be reduced by one degree. Other detail requirements shall comply with the provisions for framed structures in Section 8.3 of this code.
9 9.1
Single-story Factory Buildings
Single-story Factory Buildings with R.C. Columns
(I) 9.1.1
General
This section is mainly applicable to the fabricated single-story factory buildings with
reinforced concrete columns, and its structural arrangement shall meet the following requirements: 1
Height and length of each span in multi-span factory buildings should be equal. Structural
arrangement featured by one-end opening should not be adopted for high-low span factory buildings. 2
Attached buildings and structures of a factory building should not be arranged at the corners
of the building or close to the seismic joints. 3
The seismic joints should be installed in factory buildings with an irregular configuration or
with attached buildings and structures. The clear width of the seismic joint may be taken as 100~150mm at the junction of the longitudinal and the transversal spans of factory buildings, at the factory building with larger column-grids and at factory buildings without column bracing; and may be taken as 50~90mm at other cases. 4
For the transitional span between two main factory buildings, the seismic joints shall be
installed to separate with the main factory building on at least one side. 5
The steel ladder for getting on the crane within the factory building shall not be installed near
the seismic joint; the steel ladder for getting on the crane in multi-span factory building should not be installed near the same transversal axial line. 6
The operation platform and rigid workshop should be separated with the main structure of the 101
factory building. 7
Within the same structural unit of the factory building, the different structural systems shall
not be used, the not loading masonry gable seismic wall but the roof truss shall be installed at the end of the factory building, and compounded load-bearing by transversal masonry seismic wall and bent shall be avoided. 8
The column space of factory buildings should be equal, the lateral rigidity of each colonnade
should be even. If there is column-removed, seismic fortification measures shall be adopted. Note: the seismic design for bent frame column factory building with reinforced concrete frame shall meet the requirements of H.1 in Appendix H of this code.
9.1.2
1
Installation of the skylight truss of the factory building shall meet the following requirements: The skylight should adopt the shelter type skylights rising small out of the roof, the
basin-type skylights should be adopted when conditions are sat or for Intensity 9. 2
The convex-type skylights should adopt steel skylight; for Intensity 6 to Intensity 8, the
reinforced concrete skylight with rectangular section member bars may be adopted. 3
Skylight truss should not be arranged from the first bay of the factory building construction
unit. For Intensity 8 and 9, the first skylight-truss should be installed on the third column bracing from the end to middle of the factory buildings. 4
Roof, front sheet and lateral plate of the skylight should be made of lightweight materials.
End skylight truss shall not be replaced by the front sheet. 9.1.3
1
Installation of the roof truss for factory buildings shall meet the following requirements: Factory buildings should adopt steel roof truss, or pre-stressed concrete and reinforced
concrete roof truss with lower center of gravity. 2
When the span is less than or equal 15m, reinforced concrete roof beams may be used.
3
When the span is larger than 24m, or for Intensity 8 with Site-category Ⅲ and Ⅳ or Intensity
9, it shall be predominated that steel roof truss is to be adopted. 4
When the column space is 12m, pre-stressed concrete bracket (or beam) may be adopted, and
for steel roof truss, the steel bracket (or beam) may also be used. 5
The roof truss with convex-type skylight should not adopt pre-stressed concrete or reinforced
concrete opening-web truss. 6
For Intensity 8 (0.30g) and Intensity 9, factory building with larger than 24m span should not
adopt large-sized roof board. 9.1.4
1
Installation of columns in factory building shall meet the following requirements; For Intensity 8 and 9, the rectangular, I-shaped section column or double leg columns with
inclined web-bar should be adopted; but the thin-web I-shape columns, the opening web I-shape columns, the precast web I-shape columns and the tube columns should not be adopted. 2
Rectangular sections should be used from the bottom of the column to the scope of 500mm
above the ground floor level, or the upper column of stepped columns. 102
9.1.5
The arrangement of the enclosure seismic wall and masonry parapet of the factory building,
material selection as well as details of seismic design shall meet relevant requirements specified in Section 13.3 of this code. (Ⅱ) 9.1.6
Essentials in Calculation
Transverse and longitudinal seismic checking can be omitted, when single-story factory
building adopts details of seismic design according to the requirements of this code and meets one of the following conditions: 1
For Intensity 7 with Site-category I and II, single-span and equal-height multi-span factory
buildings (expect serrate factory buildings) with gables at both sides of the construction unit and no larger than 10m high columns. 2 9.1.7
For Intensity 7 and Intensity 8 (0.20g) with Site-category I and II, open crane trestle. The following methods shall be used for seismic calculation in transversal direction of a
factory building: 1
For the factory buildings with reinforced concrete roof with or without purlin, the multi-mass
spacious structure analysis considering the influence of transversal planar elastic deformation of the roof should be used generality. When satisfying the conditions in Appendix J of this code, it may be calculated by using planar bent analyzed method, and corresponding adjusting factors for seismic shear and bending moment of the bent as set forth in Appendix J in this code may be used. 2
For the factory buildings which have a lightweight roof and the column space is the same, the
planar bent analyzed method may be used. Note: Lightweight roof refers to a roof with purlins that made of profiled steel sheets, or corrugated irons.
9.1.8
The following methods shall be used for seismic calculation in longitudinal direction of a
factory building: 1
For the factory buildings with concrete roof with or without purlin as well as with lightweight
roof that have considerably complete bracing system, the following methods may be adopted: 1)
Generally, it should be analyzed as multi-mass spacious structures, considering the
influence of longitudinal planar elastic deformation of the roof, effective rigidity of enclosure seismic wall and partition seismic wall, as well as torsion due to asymmetry. 2)
For factory buildings with single-span or multi-spans with equal height that column
height less than or equal to 15m and the average span less than or equal to 30m, it should be analyzed by using the modification rigidity method as the requirements of K.1 in Appendix K of this code. 2
For single-span factory buildings with symmetrically-arranged longitudinal seismic wall and
multi-span factory buildings with lightweight roofs, they may be calculated separately by colonnade fragmentation. 9.1.9
The transversal seismic calculation for convex-type skylight may be carried out according to
the following methods: 1
The base shear method may be used for transverse seismic calculation of three-hinged arch
reinforced concrete with oblique braces or steel skylight truss. When the span of the skylight truss is larger than 9m or for Intensity 9, the earthquake action effect of the concrete skylight truss shall be 103
multiplied by an enhancement coefficient, which value may be taken as 1.5. 2
In other cases, the transverse horizontal earthquake action of the skylight truss may adopt the
mode-superposition response spectrum method. 9.1.10
The longitudinal seismic calculation for convex-type skylight may be carried out according
to the following methods: 1
The spacious structure analysis method may be used for seismic calculation of skylight truss
in the longitudinal direction, considering planar elastic deformation of the roof and effective rigidity of the longitudinal seismic wall. 2
Base shear method may be used in the calculation of longitudinal earthquake action for
skylight truss in the single-span or multi-span with equal height factory building, which reinforced concrete roof without purlin is used and the height of columns does not exceed 15m. But the earthquake action effect of the skylight truss shall be multiplied by the following enhancement coefficients: 1)
For the roof in a single span or a side span, or in the mid-span having longitudinal inner
partition seismic wall
2)
η=1+0.5n
(9.1.10-1)
η=0.5n
(9.1.10-2)
For the roof in other mid-spans
Where, η ——The enhancement coefficient of earthquake action effect; n ——The number of spans in the factory building; if number of spans exceeds 4, shall equal 4. 9.1.11
For a large column-grid factory building with the column space along two main axial
directions is no less than 12m, and without a bridge crane and column bracing, the horizontal earthquake action in two main axial directions shall be calculated simultaneously in seismic checking of column sections, with regard to the additional bending moment caused by displacement. 9.1.12
For factory buildings with unequal heights, the section area of the longitudinal tension
reinforcement in the column bracket, which supporting the roof with the lower span, shall be determined according to the following equation:
As≥(
N G a 0.85ho f y
N E
+ 1.2
f y
)γRE
(9.1.12)
Where, A ——The section area of the longitudinal tension reinforcement; s NG ——The design value of pressure caused by the representative value of gravity load on the column bracket; a ——The distance from the gravity action point to the near edge of the lower column bracket; when it is less than 0.3ho, shall equal 0.3h o; ho ——The effective height of the largest vertical section of the bracket; 104
NE ——The design value of horizontal tension in the seismic combination on the top of the column bracket;
f y ——The design value of reinforcement tensile strength; γRE ——The seismic adjusting factor for bearing capacity, it may be taken as 1.0. 9.1.13
The earthquake action effect of the column cross bracing diagonal as well as the seismic
checking for the connecting joint between it and the column may be carried out according to the requirements of K.2 in Appendix K of this code. When the lower joint of lower column bracing is set on the top surface of the foundation according to the requirements of Article 9.1.23 in this code, diagonal section shear-bearing capacity checking calculation should be carried out for longitudinal colonnade and column root. 9.1.14
Wind-resistant column and roof truss column of the factory building, as well as seismic
calculation with regard to the influence of operation platform shall meet the following requirements: 1
For Intensity 8 and 9, the out-of-plane sectional seismic checking shall be made for the
wind-resistant column of tall gables. 2
When the wind-resisting column is connected with the bottom chord of roof truss, the
connecting point shall be arranged at the joint of the transverse brace of the bottom chord, and seismic checking shall be made for the section and connecting joints of the transverse bracing member bars of the bottom chord. 3
When the operation platform and rigid inner partition seismic wall are connected with the
main structures of the factory building, the calculating diagram corresponding to the actual force-bearing state of the factory building s hall be adopted, and the additional earthquake action e ffect of that on this factory building shall be taken into consideration. As for the bent frame columns whose deflection is restricted and shear-span ratio is no larger than 2, the shear capacity of their diagonal sections shall be calculated according to the requirements of the current national standard “Code for Design of Concrete Structures” GB 50010, and corresponding details of seismic design shall be adopted according to Article 9.1.25 of this code. 4
For Intensity 8 with Site-category Ⅲ and Ⅳ and for Intensity 9, the arched and fold-line roof
truss with small columns or the roof truss with longer top chord internode and larger vector height, the torsional checking calculation should be made for the top chord of these roof trusses. (Ⅲ) 9.1.15
Details of Seismic Design
Connection of components and arrangement of braces in the roof with purlin shall meet the
following requirements; 1
The purlins shall be welded tightly with the concrete roof truss (roof beam), and shall be
possessed of sufficient bracing length. 2
Both purlins of the double-ridge purlin shall be tied with each other at 1/3 of the span.
3
The profiled steel sheets shall be connected reliably with purlins, as well as the corrugated
irons and asbestos sheets shall be tied with purlins. 4
Arrangement of braces should meet those specified in Table 9.1.15. 105
Table 9.1.15
Brace Arrangement for Roof with Purlin Intensity
Braces Intensity 6 and 7
Intensity 8
Intensity 9
One row in each end bay of a factory One row in each end
building unit, the column bracing bay of a
Transverse braces
unit with length larger than 66m;
bay of a factory at the top chord building unit
One row of local brace at both ends of the skylight opening scope
Braces of
One row in each end bay of a factory unit, the column bracing bay of a unit with length larger than 42m; One row of local transverse brace at
the roof
Transverse braces
truss
at bottom chord
the top chord at both ends of the skylight opening scope
Same as the non-seismic design Vertical braces at midspan
Vertical braces at When the roof truss end height is larger than 900mm, one row in each end bay and column bracing bay of the end
Braces of
a unit
Transverse braces
One row in each skylight end bay of a
at the top chord
unit
Vertical braces at
One row in each skylight end bay of a
two sides
unit and in each 36m spacing
One row in each skylight end bay of a
One row in each skylight end bay of a
unit and in each 30m
unit and in each 18m spacing
the skylight truss
9.1.16
spacing
Connection of components and arrangement of braces in the roof without purlins shall meet
the following requirements: 1
Large-sized roof boards shall be welded firmly with the roof truss (roof beam), and length of
the attachment welds of the roof board adjacent to the colonnade and the roof truss (roof beam) should be no less than 80mm. 2
For the end bay of a factory unit with a skylight of Intensity 6 and 7, or for each bay of
Intensity 8 and 9, adjacent large-sized roof boards which perpendicular to the roof truss should be welded with each other at their top surfaces. 3
For Intensity 8 and 9, angle steel should be used for embedded parts at the bottom of the end
of the large-sized roof board, and it shall be welded firmly with the main reinforcement. 4
For non-standard roof board, assembled monolithic joint should be used, or all corners of the
board should be cut and then welded firmly with the roof truss (beam). 5
Anchoring bars of the embedded parts on the top of the end of the roof truss (roof beam)
should not be less than 4φ10 for Intensity 8 and 4φ12 for Intensity and 9. 6
Arrangement of braces should meet the requirements in Table 9.1.16-1 and in Table 9.1.16-2
for the basin-type skylight. For Intensity 8 and 9, when the roofs of factory buildings whose spans are no larger than 15m adopt roof beams, it may be installed only one vertical brace at each end of a 106
factory unit. The roof brace arrangement of single-slope roof beam should be carried out according to roof brace arrangement with larger than 900mm roof truss end height.
Table 9.1.16-1
Brace Arrangement for Roof without Purlin Intensity
Braces Intensity 6 and 7
Intensity 8
Intensity 9
Same as non-seismic design when the roof truss span is less than Transverse braces at the
One row in each end bay of a factory unit, and the column bracing bay; 18m;
top chord
One row of local brace at both ends of the skylight opening scope One row in each end bay of a factory unit when the span ≥18m One row along the roof truss in no
One row along the roof truss in no
larger than 15m span, but it may be larger than 12m span, but it may be only installed at the scope of
only installed at the scope of
skylight opening for assembled
skylight opening for assembled
monolithic roof; it may not be
monolithic roof; it may not be
installed at the end when there are
installed at the end when there are
cast-in-situ ring beams at the top
cast-in-situ ring beams at the top
Full-length horizontal tie Braces of
bar at the top chord
the
chord of the roof truss of enclosure chord of the roof truss of enclosure
roof truss Same as non-seismic
seismic wall
seismic wall
design Transverse braces at the bottom chord
Same as transverse braces at the Same as non-seismic design top chord
Vertical braces at the midspan
One row in each end bay of a End height
One row in each end bay of a
≤900mm
factory unit
factory unit and in each 48m Vertical
spacing
braces at two ends
End height
One row in each end bay
>900mm
of a factory unit
One row in each end bay of a
One row in each end bay of a
factory unit and the column bracing
factory unit, the column bracing
bay
bay and in each 30m spacing
One row in each skylight end bay of
One row in each skylight end bay
a factory unit and in each 24m
of a factory unit and in each 18m
For span of skylight is no less than
One row in each end bay of
9m, one row in each end bay of
skylight and the column bracing
skylight and the column bracing bay
bay
One row in each skylight Vertical braces at two sides Braces
end bay of a factory unit of the skylight and in each 30m
of the skylight truss
Transverse braces at the
Same as non-seismic
top chord
design
107
Table 9.1.16-2 Braces Transverse braces at the top chord
Brace Arrangement of Basin-type Skylight Roof without Purlin Intensity 6 and 7
Intensity 8
Intensity 9
One row in each end bay One row in each end bay of a factory unit and the column bracing bay
Transverse braces at the bottom chord
of a factory unit
Full-length horizontal tie bar at the In the joints of the top chord of the roof truss midspan within the scope of skylight top chord Full-length horizontal tie bar at the
At both sides of skylight and in the joints of the bottom chord of the roof truss within the scope of
bottom chord
skylight With transverse brace bay installation at the top chord, corresponding to the full-length tie bar at the
Vertical brace at midspan bottom chord
With transverse brace bay at the top End height ≤900mm
Same as non-seismic design chord, and spacing ≤48m
Vertical braces at both ends One row in each end bay With transverse brace bay at the top With transverse brace bay at the top End height >900mm of a factory unit
9.1.17
1
chord, and spacing ≤48m
chord, and spacing ≤30m
The braces of the roof shall also meet the following requirements: Within the opening zone caused by skylight, a full-length horizontal compression bar at the
top chord shall be installed at the ridge of the truss. For Intensity 8 with Site-category III and IV and Intensity 9, the upper joints on the trapezoidal roof truss end shall be equipped with full-length horizontal compression bars along the longitudinal direction of the factory building. 2
The spacing of vertical braces at the roof truss midspan along the direction of span: shall not
be larger than 15m for Intensity 6 to Intensity 8, and no larger than 12m for Intensity 9. When only one row is installed at the midspan, the location shall be the ridge of the midspan roof truss; when two rows are to be installed, they shall be arranged evenly along the direction of span. 3
The full-length horizontal tie bars at the top and bottom chord should be arranged matching
with the vertical braces of the roof truss. 4
For factory buildings with column space no less than 12m and the roof truss space 6m,
vertical horizontal braces at the bottom chord shall be installed in the bracket (beam) section and its adjacent bays. 5 9.1.18
The bracing member bars of the roof truss should adopt profile steel. For the reinforced concrete convex-type skylight truss, the seismic wall boards on both sides
should be connected with columns of skylight by using bolts. 9.1.19
The section and reinforcement of the reinforced concrete roof truss shall meet the following
requirements: 108
1
For the reinforcements in the first internode at the top chord of the roof truss and of
trapezoidal roof truss vertical bars, they should not be less than 4 φ12 for Intensity 6 and 7, and 4 φ14 for Intensity 8 and 9. 2
The sectional width of the end vertical bar of the trapezoidal roof truss should be the same as
that of the top chord. 3
For the small columns supporting the roof boards at the end of the top chord of the arched
and fold-line roof truss, the section dimension should not be less than 200mm×200mm, and the height should not be greater than 500mm. Main reinforcements in the small columns shall adopt Ⅱ-type and no less than 4φ12 for Intensity 6 and 7, and 4φ14 for Intensity 8 and 9; the hoops in small columns may adopt φ6, and the spacing should not be larger than 100mm. 9.1.20
1
The hoops in a column of the factory building shall meet the following requirements: The hoops shall be densified in the following scope: 1)
The column top, for a length of 500mm from the top of the column, and also no less
than the dimension of the longer side of the column section; 2)
Upper column, from the bracket surface to a distance of 300mm above the crane beam
surface of a stepped column; 3)
Bracket (the column shoulder), full height;
4)
The column root, from the bottom of the lower column to a distance of 500mm above
the indoor ground level; 5)
The connecting joints between column bracing and column as well as positions where
column deflection are constrained by the platform, a distance of 300mm above and below of the joints. 2
The spacing of hoops in the densified zone shall not be larger than 100mm, and the spacing
between legs and minimum diameter of the hoop shall meet those specified in Table 9.1.20.
Table 9.1.20
Maximum Distance and Minimum Diameter of Hoops in the Densified Zone
Intensity 6, Intensity 7 Intensity 7 with Site-category Ⅲ with Site-category I,
and Ⅳ, Intensity 8 with
Site-category Ⅲ and Ⅳ ,
Ⅱ
Site-category I and Ⅱ
Intensity 9
300
250
200
Common column top and root
φ6
φ8
φ8 (φ10)
Column top of corner column
φ8
φ10
φ10
φ8
φ8
φ10
Intensity and Site class
Maximum spacing for legs of hoop (mm) Min. diameter
Intensity 8 with
of hoop
Bracket of upper column and column root with brace
109
Column top with brace and position at which column deflection is
φ8
φ10
φ12
constrained Note: Values in the brackets are used for the column root.
3
As for the laterally-constrained bent frame columns with no larger than 2 shear span ratio, the
structure of the embedded steel plate on the top of the column and the column hoop densified area shall meet the following requirements: 1)
The length of the embedded steel plate on the top of the column along the bent frame
plane should be equal to the sectional height of the column top, and must not be less than 1/2 of the sectional height and 300mm; 2)
As for the installation position of the roof truss, the eccentricity on the top of the
column should be reduced; the eccentricity of axial force on the top of the column shall not be larger than 1/4 of the sectional height; 3)
When the eccentricity on the plane of column top axial force bent frame is at the range
of 1/6~1/4 of the sectional height, the transverse reinforcement ratio of hoops on the column top hoop densified area: should not be less than 1.2% for Intensity 9; 1.0% for Intensity 8; 0.8% as for Intensity 6 and 7; 4)
Hoops in the densified area should be equipped with four-leg hoops with no larger than
200mm leg distance. 9.1.21
The section and reinforcement for columns of factory building with large-sized column-grid
shall meet the following requirements: 1
The column section should adopt the square or nearly square rectangular shapes, and the side
length should not be less than 1/18~1/16 of the total height of the column. 2
The column axial-compression-ratio of heavy weight roof factory building, should not be
larger than 0.8 for Intensity 6 and 7, 0.7 for Intensity 8, and 0.6 for Intensity 9. 3
Longitudinal reinforcements should be arranged symmetrically along the perimeters of the
column section, the spacing should not be larger than 200mm; and the reinforcements with larger diameter should be arranged at the corner of section. 4
The hoops at the column top and column root shall be densified in accordance with the
following requirements: 1)
For the column root, the densified scope from the foundation top surface to a distance
of 1m above the indoor ground level, and this distance shall not be less than 1/6 of the total height of the column. For the column top, 500mm below the top of the column and the distance shall not be less than the larger side dimension of the column section; 2)
The spacing, diameter and the leg spacing of the hoops shall meet the requirements in
Article 9.1.20 of this code. 9.1.22
1
Reinforcement of wind-resisting column of the gable shall meet the following requirements: For the hoops within the scope of 300mm below the top of the wind-resisting column and
300mm above the brackets (column shoulder), the diameter should not be less than 6mm, the spacing 110
should not be larger than 100mm, and the spacing of legs should not be larger than 250mm. 2
Longitudinal tensile reinforcements should be installed at the brackets (column shoulder) of
the variation section of the wind-resisting column. The arrangement and structures of the column bracings in the factory building shall meet the
9.1.23
following requirements: 1
The arrangement of column bracings shall meet the following requirements: 1)
Generally, column bracings shall be installed for the upper and lower columns in the
middle of the factory building unit, and the braces of the lower column and the upper columns shall be installed correspondingly; 2)
When there are cranes or for Intensity 8 and 9, braces of upper columns should be
installed at the both ends of the factory building unit; 3)
When the factory building unit is long or for Intensity 8 with Site-category Ⅲ and Ⅳ or
for Intensity 9, two rows of column bracings may be arranged in 1/3 length scope measured from both ends of the factory unit. 2
The column bracings shall adopt profile steel, the brace type should adopt crossed type, the
angel between the diagonal and the plane should not be larger than 55°. 3
The slenderness ratio of the bracing member bar should not exceed the limits in Table 9.1.23.
Table
9.1.23
Maximum Slenderness Ratio of Crossed Brace Diagonals Intensity Intensity 9 with
Site
Intensity 6, Intensity 7
Intensity 7 with Site-category Ⅲ
Intensity 8 with Site-category Ⅲ
with Site-category I and
and Ⅳ, Intensity 8 with
and Ⅳ, Intensity 9 with
Ⅱ
Site-category I and Ⅱ
Site-category I and Ⅱ
250
250
200
150
200
150
120
120
Site-category Ⅲ and Ⅳ
Brace of upper column Brace of lower column
4
The location of the lower joint and structural measures for the brace of lower column shall
ensure to directly transfer the earthquake action to the foundation. For Intensity 6 and 7 (0.10g), if the earthquake action cannot be transferred directly to the foundation, strengthened measures shall be adopted with regard to the adverse effects of the brace on the column and the foundation. 5
The gusset plate shall be installed at the intersecting point of the crossed brace, and the plate
thickness shall not be less than 10mm. The diagonals shall be welded to the crossed gusset plates and the end gusset plates. 9.1.24
As for the center columns of multi-span factory buildings with no less than 18m span in
Intensity 8, and each column of multi-span factory buildings in Intensity 9, the full-length horizontal 111
compression bars should be installed on the top of the columns. This compression bar may be installed combining with the full-length horizontal tie bars at the support of the trapezoidal roof truss. The clearance between the end of the reinforced concrete tie bar and the roof truss shall be filled with concrete. 9.1.25
The connecting joints of the structural components in a factory building shall meet the
following requirements: 1
The roof truss (beam) should be connected with column top by bolts for Intensity 8 and by
hinge plate for Intensity 9, but bolts may also be used for Intensity 9. The thickness of the bearing subplate at the end of the roof truss (beam) should not be less than 16mm. 2
The anchoring bars of embedded parts on top of a column should not be less than 4φ14 for
Intensity 8 and 4φ16 for Intensity 9. For columns with column bracing, shear plate shall be installed additionally for the embedded parts on the top of column. 3
The embedded plate shall be put on the top of the wind-resisting column in a gable seismic
wall, so that top of the column can be reliably connected with the top chord of the end roof truss (or top flange of the roof beam). The connected point shall be installed at the joint of top chord transverse brace and roof truss; if not, additionally sub-web or profile steel beam may be installed to transfer the horizontal earthquake action to this joint. 4
The embedded parts in the bracket (column shoulder) of the middle-column supporting the
lower-span roof shall be welded with the longitudinal reinforcement subjected to the calculated horizontal tension in the bracket (column shoulder). And the welded reinforcements shall not be less than 2φ12 for Intensity 6 and 7, 2φ14 for Intensity 8, and 2φ16 for Intensity 9. 5
For Intensity 8 with Site-category Ⅲ or Ⅳ and for Intensity 9, the angle steels together with
end plate should be used as anchoring pieces of the embedded parts at the joint of the column bracing and the column. And in other cases, the hot-rolled reinforcement no less than HRB335 may be adopted, but the anchorage length shall be no less than 30 times of the anchoring bar diameter and the added end plate. 6
The crane sidewalk, the small roof board filled the space between the end roof truss and gable,
gutter board, the filling masonry underneath the skylight end plate and side plate etc. shall have reliable connection with its supporting structural components. 9.2
Single-story Steel Factory Buildings
(I) 9.2.1
General
This section is mainly applicable to steel column, steel roof truss or steel roof beam bearing
single-story factory buildings. The seismic design for single-story factory buildings with lightweight steel structures shall meet special requirements. 9.2.2
1
The structural system of the factory building shall meet the following requirements: Rigid-connection frame, hinged frame, portal rigid frame or other structural systems may be
adopted for the transverse lateral-force-resisting system of factory buildings. As for the longitudinal lateral-force-resisting system of factory buildings, column bracing shall be adopted for Intensity 8 and 9; column bracing or rigid-connection frame should be adopted for Intensity 6 and 7. 2
When bridge crane is installed in the factory building, the connection between the 112
components of crane beam system and the frame column of factory building shall be able to reliably transfer vertical horizontal earthquake action. 3
The roof shall be equipped with complete roof brace system. When the transverse beam of
the roof is in hinged connection with the column top, bolted joint should be adopted. 9.2.3
The factory building plane, reinforced concrete roof board and skylight truss can be arranged
in accordance with the requirements of Section 9.1 “Single-story factory buildings with reinforced concrete columns” in this code. When seismic joints are arranged, the joint width should not be less than 1.5 times of that of single-story factory building with reinforced concrete column. 9.2.4
The enclosure seismic wall boards of factory buildings shall meet the relevant requirements of
Section 13.3 in this code. (Ⅱ) 9.2.5
Seismic Checking
In the seismic calculation of factory buildings, the earthquake action shall be calculated with
calculation model corresponding to the actual working conditions of factory building structures, according to the roof height difference and crane arrangement conditions. The damping ratio of single-story factory building can adopt 0.045~0.05 according to the types of roofs and enclosure seismic wall. 9.2.6
For the calculation of earthquake action of factory buildings, the weight and rigidity of the
enclosing seismic wall shall meet the following requirements: 1
For lightweight seismic wall boards or precast reinforced concrete seismic wall boards that
flexibly connected with columns, the total weight of the seismic wall shall be considered, but influence of rigidity may not be considered. 2
For masonry enclosure seismic wall closely built to and tied to the columns, the total weight
of seismic wall shall be considered. When the earthquake action is calculated longitudinally along the seismic wall, the conversion rigidity and conversion coefficient of common brick masonry seismic wall shall be taken into consideration, 0.6, 0.4 and 0.2 for Intensity 7, 8 and 9 respectively. 9.2.7
The following method may be adopted for seismic calculation in transversal direction of the
factory building: 1
The spacious structure analysis considering the influence of elastic deformation of the roof
should be used generally; 2
As for the lightweight roof factory buildings with regular plane and uniform lateral rigidity, it
can be calculated according to the plane framework. Base shear method may be adopted for the equal-height factory buildings; mode-decomposition response spectrum method shall be adopted for high-low span factory buildings. 9.2.8
The following method may be adopted for seismic calculation in longitudinal direction of the
factory building: 1
As for factory buildings with lightweight board enclosure seismic wall or large-sized seismic
wall boards flexibly connected with columns, it can be calculated with base shear method. The earthquake action of each longitudinal colonnade can be distributed according to the following principles: 113
1)
For lightweight roof, the distribution may be made according to the gravity load
representative value of the colonnade; 2)
For reinforced concrete roof without purlins, the distribution may be made according to
the rigidity ratio of the longitudinal colonnade; 3)
For reinforced concrete roof with purlins, the average value of the above mentioned two
results may be adopted. 2
As for factory buildings with common brick masonry enclosure seismic wall which are
closely built to and tied with columns, it shall be calculated according to the requirements of Section 9.1 of this code. 3
As for the colonnade equipped with column bracing, the earthquake action effect after flexion
of bracing member bars shall be taken into consideration. 9.2.9
Seismic calculation of the factory building roof components shall meet the following
requirements: 1
The web members of vertical bracing truss shall be able to bear and transfer horizontal
earthquake action of the roof. The bearing capacity of its connection shall be larger than that of the web member and meet the detailing requirements. 2
The crossed diagonals of both roof transverse horizontal brace and longitudinal horizontal
brace can be designed as the draw bar and adopt the same sectional areas. 3
For Intensity 8 and 9, as for the bracket of roof beam with larger than 24m bracing span as
well as the roof beam with larger equipment loads, their vertical earthquake action shall be calculated according to Section 5.3 of this code. 9.2.10
The combined action of tension/compression members shall be taken into consideration for
X-bracing, V-bracing or
Λ -bracing between columns. Their earthquake action and checking
calculation can be calculated as draw bar according to the requirements of Section K.2 in Appendix K of this code, and the influence of intersecting compression bars shall be taken into consideration, but the compression bar unloading coefficient should adopt 0.30. As for the connection of X-brace end, Intensity reduction shall be counted in for single angle steel; single-side eccentric connection must not be adopted for Intensity 8 and 9. In X-brace, if one bar breaks, crossed gusset plates shall be strengthened, and their bearing capacity shall not be less than 1.1 times of that of member bars. Sectional stress ratio of bracing member bars should not be larger than 0.75. 9.2.11
The bearing capacity calculation of factory building structural component connection shall
meet the following requirements: 1
The splicing positions of frame upper columns shall select areas with smaller bending
moment. Its bearing capacity shall not be less than the internal force at the splicing point calculated according to the bulk sectional plastic yielding state at both sides of upper columns, and must not be less than 0.5 times of tensile yielding bearing capacity of column total section. 2
Splicing of rigid frame roof beam, outside of maximum beam stress region, should be
designed as equal strength to the spliced section. 114
3
As for the rigid connection between solid web roof beam and column, as well as splicing
between beam end beam and beam, seismic combination internal force shall be adopted for elastic stage design. The ultimate flexural capacity of beam-column rigid connection and beam-beam splicing shall meet the following requirements: 1)
In general, connection coefficient can be considered for checking calculation according
to the requirements of steel structure beam-column rigid connection and beam-beam splicing in Article 8.2.8 of this code. Therein, when the maximum stress region is on the upper column, fully plastic flexural bearing capacity shall adopt the smaller value between solid web beam and upper column. 2)
When the roof beams adopt plate width-to-thickness ratio at the elastic design stage of
steel structures, beam-column rigid connection and beam-beam splicing shall be able to reliably transfer precautionary Intensity seismic combination internal force or checking calculate according to No. 1 of this item. The connecting plates between rigid connection frame roof truss top chords and columns should not appear plastic deformation under precautionary earthquake. 4
The connection between column bracing and components shall not be less than 1.2 times of
plastic bearing capacity of bracing member bars. (Ⅲ) 9.2.12
Details of Seismic Design
Roof brace of factory buildings shall meet the following requirements:
1
Brace arrangement of roof without purlin should meet the requirements in Table 9.2.12-1.
2
Brace arrangement of roof with purlin should meet the requirements in Table 9.2.12-2.
3
When the light-weight roofs adopt the rigid frame systems of solid web roof beam and
column rigid connection, roof horizontal brace can be arranged on the top flange plane of roof beam. The lower flange of roof beam shall be equipped with knee-bracing lateral brace. The other side of knee brace can be connected with the roof purlin. See the requirements in Table 9.2.12 for the arrangement of roof transverse brace and longitudinal skylight truss brace. 4
The arrangement of roof longitudinal horizontal brace shall meet the following requirements: 1)
When the roof structure with bracket supporting roof beam is adopted, longitudinal
horizontal brace shall be installed along the full length of factory building unit; 2)
As for high-low-span factory buildings, longitudinal horizontal brace shall be arranged
along full length of roofs at the end brace of low-span roof beam; 3)
When longitudinal colonnade local columns adopt brackets to support roof beams, roof
longitudinal horizontal braces shall be arranged along bracket columns and at least one column extended toward both sides; 4)
When the full-length vertical horizontal braces along the structural unit are installed,
they shall form sealed horizontal bracing system with transverse horizontal braces. Vertical horizontal bracing space of multi-span factory building roofs should not exceed two spans and must not exceed three spans. High span and low span should form relatively independent sealed bracing system according to their respective elevations. 115
5
Bracing member bars should adopt profile steels. When the X-brace is arranged, the
slenderness ratio limit value of bracing member bar can adopt 350.
Table
9.2.12-1
Brace System Arrangement for Roof without Purlin Intensity
Braces Intensity 6 and 7
Intensity 8
Intensity 9
Same as non-seismic design when the span Transverse braces at the
is less than 18m;
One row in each end bay of a factory unit, and the upper column bracing bay; one row of local brace at the top chord at both ends of the skylight opening scope; when the end brace of the roof truss is on the top chord of the roof
top and bottom chord
One row in each end
truss, the transverse brace at the bottom chord is the same as the non-seismic
bay of a factory unit
design
when the span ≥18m
Braces of the
Full-length horizontal tie
On the ridge, vertical brace of the skylight truss, joint of the transverse brace
bar at the top chord
and both ends of the roof truss On the joint of the roof truss vertical brace; when the roof truss is in rigid
Full-length horizontal tie connection with the column, on the roof truss end internode according to the bar at the bottom chord outer slenderness ratio of controlling bottom chord plane no larger than 150
roof truss As Intensity 8, and Roof truss
Same as non-seismic
One row on each end bay of factory building unit and
span<30m
design
on each roof truss end of top column brace bay
on the end of roof truss in each 42m
Vertical braces
On the end bay of factory building unit, 1/3 span of the As Intensity 8, and Roof truss
roof truss and roof truss end in the top column brace
span≥30m
bay; corresponding to the transverse brace at the top
on the end of roof truss in each 36m and bottom chord
One row in both end Transverse braces at the bay of a skylight truss
One row in each end bay of a skylight truss and the column bracing bay
top chord unit
Vertical braces
Rows are the same as Midspan
of the skylight
Vertical
truss
brace
both sides, when the
Rows are the same as both sides, when the span≥9m
span≥12m One row in each end
One row in each end One row in each end bay of skylight truss and in each
Both sides
bay of skylight truss
bay of skylight 30m
and in each 36m
Table
9.2.12-2
truss and in each 24m
Brace System Arrangement for Roof with Purlin
116
Intensity Braces Intensity 6 and 7
Intensity 8
Intensity 9
One row in each end bay
One row in each end bay of factory
As Intensity 8, one row of local top
Transverse braces at of factory building unit
uilding unit and on each column bracing chord transverse brace at both ends at
the top chord and in each 60m
bay of top column
the range of skylight opening
Transverse braces at Same as non-seismic design; when the end brace of the r oof truss is on the bottom chord of the roof truss, the bottom chord
the same as the transverse brace of the top chord
Braces of the roof truss
When roof truss span≥30m, another
Vertical brace at Same as non-seismic design midspan
row in midspan
Vertical brace at When roof truss end height >900mm, one row on end bay of factory building unit and column bracing bay both sides Full-length
At both ends and vertical brace of the roof truss; when the roof truss is in rigid Same as non-seismic
horizontal tie bar at
connection with the column, on the roof truss end internode according to the design
the bottom chord Vertical braces
Transverse braces at One row in each end bay the top chord
of the skylight truss
9.2.13
outer slenderness ratio of controlling bottom chord plane no larger than 150
of a skylight truss unit
One row in each end bay of a skylight
One row in each end bay of a
truss unit and in each 54m
skylight truss unit and in each 48m
One row in each end bay of a skylight
One row in each end bay of a
truss unit and in each 36m
skylight truss unit and in each 24m
One row in each end Vertical braces at bay of a skylight truss two sides unit and in each 42m
As for the slenderness ratio of factory building frame columns, it should not be larger than
150 when the axial force ratio is less than 0.2; it should not be larger than 120 235 / f ay when the axial force ratio is no less than 0.2. 9.2.14
The width-to-thickness ratio of factory building frame column and beam slabs shall meet the
following requirements: 1
As for the heavy-roof factory buildings, plate width-to-thickness ratio limit value can be
adopted according to the requirements of Article 8.3.2 in this code. Intensity 7, 8 and 9 seismic Grades can be adopted respectively according to Class IV, III and II. 2
As for light-roof factory buildings, plate width-to-thickness ratio limit values in the plastic
energy consumption region can be determined according to performance objectives based on their bearing capacity degree. Plate width-to-thickness ratio limit values outside of plastic energy consumption region can adopt those at the stage of elastic design in the current “Code for design of steel structures” GB 50017. Note: the width-to-thickness ratio of webs can be reduced through installing longitudinal ribbed stiffeners.
9.2.15
1
Column bracing shall meet the following requirements: As for each longitudinal colonnade of factory building unit, one row of lower column brace
shall be arranged in the middle of factory building unit. When Intensity 7 factory building unit length is larger than 120m (150m when adopting light-weight protective materials), Intensity 8 and 9 factory 117
building units are larger than 90m (120m when adopting light-weight protective materials), one row of lower column brace shall be arranged in each 1/3 section of factory building unit. When column numbers are no larger than 5 and factory building length is less than 60m, lower column braces can be arranged at both sides of factory building units. Upper column brace shall be arranged at both sides of factory building units and columns with lower column braces. 2
Column bracing should adopt X-bracing, can adopt V-bracing,
Λ -bracing or other types if
constrained. The included angle between the X-bracing diagonal and horizontal plane, as well as gusset plate thickness at the junction of bracing diagonals shall meet the requirements of Section 9.1 in this code. 3
Slenderness ratio limit value of column bracing member bars shall meet the
requirements of the current national standard “Code for design of steel structures” GB 50017. 4
Column bracing should adopt the whole profile steel. When the hot-rolled profile steels
exceed the maximum length specifications of materials, splicing can be adopted to prolong profile steels in equal strength. 5 9.2.16
Energy-dissipated braces may be used if the condition is available. Column base shall be able to reliably transfer the bearing capacity of column body.
Embedded type, plug-in type or out column base should be adopted. For Intensity 6 and 7, exposed column base may also be adopted. The column base design shall meet the following requirements: 1
Solid web steel columns shall adopt embedded type. The embedded depth of plug-in type
column base shall be determined through calculation and must not be less than 2.5 times of steel column sectional height. 2
Structural columns shall adopt plug-in type. The embedded depth of column base shall be
determined through calculation. The minimum plug-in depth must not be less than 2.5 times of single leg sectional height (or outside diameter) and must not be less than 0.5 times of column total width. 3
When out column bases are adopted, reinforced concrete out height of solid web H section
column should not be less than 2.5 times of steel structure sectional height; the reinforced concrete out height of box section column or circular pipe section column should not be less than 3.0 times of steel structure sectional height circular pipe sectional diameter. 4
When exposed column bases are adopted, column base bearing capacity should not be less
than 1.2 times of column section plastic yielding bearing capacity. Column base anchor bolt should not be used for bearing the horizontal shear at the bottom of the column. The shearing force at the bottom of columns shall be undertaken by the frictional force between steel soleplate and foundation, installing shear keys and other measures. Column base anchor bolts shall be anchored reliably. 9.3
Single-story Factory Buildings with Brick Columns
(I) 9.3.1
General
This section is applicable to the following medium-and small-sized single-story factory
buildings with brick column (pier) bearing loads built by Intensity 6~8 (0.20g) fired common bricks (clay bricks and shale bricks) and concrete stock bricks. 1
Single span, equal-height multi-span and without bridge crane.
2
Span is no larger than 15m and column top elevation is no larger than 6.6m. 118
9.3.2
The structural arrangement of factory buildings shall meet the following requirements and
should meet relevant requirements in Article 9.1.1 of this code: 1
Brick bearing gables shall be installed at both sides of factory buildings.
2
Transverse and longitudinal inner partition seismic wall with equal height and connected with
columns should adopt brick seismic wall. 3
Seismic joint shall be installed in accordance with the following requirements: 1)
As for light-weight roof factory buildings, seismic joints may not be installed;
2)
Seismic joints should be installed between reinforced concrete roof factory buildings
and their attached buildings (structures). Seismic joint width can adopt 50mm~70mm. Double columns or double seismic wall shall be installed at the seismic joints. 4
Skylight shall not be open to the end bay of factory building units and shall not adopt end
brick seismic wall bearing. Note: light-weight roofs in this chapter refer to wood roof, light steel roof truss, profiled steel sheet and corrugated iron, etc.
9.3.3
The structural system of a factory building shall also meet the following requirements:
1
Factory building roofs should adopt light-weight roofs.
2
The cross-shaped section plain brick columns may be used for Intensity 6 and 7; brick
columns without tendons shall not be adopted for Intensity 8. 3
As for the independent brick column colonnade in the longitudinal direction of the factory
building, seismic wall with equal height to columns shall be installed among columns to bear the longitudinal earthquake action. A full-length horizontal compression bar shall be installed on top of the independent brick column without seismic wall. 4
Transversal and longitudinal inner partition seismic wall should adopt seismic wall.
Lightweight seismic wall should be used for non-bearing transversal partition seismic wall or longitudinal partition seismic wall whose height is less than that of column. When normal-weight seismic wall are used, additional seismic shear on the column and its connection with the roof truss caused by the partition seismic wall shall be considered. For independent transversal and longitudinal partition seismic wall, measures shall be adopted to ensure the stability of the seismic wall outside the plane, and cast-in-situ reinforced concrete capping beams shall be installed on the top of the seismic wall. (Ⅱ) 9.3.4
Essentials in Calculation
As for the single-story buildings with brick columns whose seismic structural measures are
adopted according to the requirements of this code, if one of the following conditions is met, transverse or longitudinal sectional seismic checking can be omitted: 1
For Intensity 7 (0.10g) with Site-category I or Ⅱ, the column top elevation less than or equal
to 4.5m, the single-span and equal-height multi-span factory building with brick columns, both gable seismic wall has been installed, the seismic checking in transverse and longitudinal directions may not be carried out. 2
For Intensity 7 (0.10g) with Site-category I or Ⅱ, the column top elevation no larger than 119
6.6m, lengthwise outer seismic wall whose thickness is no less than 240mm and opening sectional area is no larger than 50% installed at both sides, single-span factory building, both gable s eismic wall has been installed, the seismic checking in longitudinal directions may not be carried out. 9.3.5
The following method may be used for the seismic calculation in the transversal direction for
factory buildings: 1
Lightweight roof factory buildings may be calculated according to planar bents.
2
The factory building assigned to reinforced concrete roof or wood roof with fully covered
sheathings may be calculated according to planar bents that the work of space has been considered, and the earthquake action effect shall be adjusted according to Appendix J of this code. 9.3.6
The following methods may be used for the seismic calculation in longitudinal direction for
the factory building: 1
For the factory buildings assigned to reinforced concrete roof, the mode-decomposition
response spectrum method may be adopted. 2
For the factory buildings assigned to reinforced concrete roof and multi-span with equal
height, the modification rigidity method as set forth in Appendix K in this code may be adopted. 3
For single-span factory buildings and multi-span factory building with lightweight roof that
longitudinal seismic wall arranged symmetrically, they may be calculated separately by colonnade fragmentation 9.3.7
The longitudinal and transversal seismic calculation for convex-type skylight truss shall meet
the requirements in Article 9.1.9 and Article 9.1.10 of this code. 9.3.8
For eccentric compressive brick-columns, the seismic checking shall meet the following
requirements: 1
For plain brick columns, the eccentricity of the seismic combinatory axial force design value
should not exceed 0.9 times of the distance from the section centroid to the section edge in the direction where the axial force locates, and the seismic capacity adjustment factory may adopt 0.9. 2
The reinforcement amount for composite brick columns shall be determined through
calculation, and the seismic capacity adjustment factor may adopt 0.85. (Ⅲ) 9.3.9
Details of Seismic Design
The braces of light-weight roofs such as steel roof truss, profiled steel sheet and corrugated
iron can be installed according to the requirements in Table 9.2.12-2 of this code. The transverse braces of top and bottom chords shall be arranged in the second bay at both sides. The brace arrangement of wood roofs should meet the requirements of Table 9.3.9. The brace and roof truss or skylight truss shall adopt bolted connection. The side columns of wood skylight truss should adopt full-length wood plywood or iron plate as well as adopt bolts to strengthen their connection with roof truss top chord.
Table Braces
9.3.9
Arrangement of Braces in a Wood Roof Intensity
120
6, 7
8 In full
All type of roofs
Scattered or no sheathing sheathing When the roof truss span is larger than 6m, one row in
Transverse braces at the top Same as the non-seismic design
the second bay at two ends of building unit and in each
chord 20m Roof truss brace
Transverse braces at the Same as the non-seismic design bottom chord Vertical brace at the midspan
Same as the non-seismic design
Vertical braces at two sides of the skylight
Skylight
Same as the non-seismic Without skylight
truss brace
Transverse braces at the top
design
chord
9.3.10
The purlins shall be connected reliably with the gable beams and shelf length shall not be less
than 120mm; when condition is available, the roof structure for purlins extended out of the gable may be adopted. 9.3.11
The details of seismic design for reinforced concrete roofs shall meet the relevant
requirements specified in Section 9.1 of this code. 9.3.12
A cast-in-situ closed ring-beam shall be installed along the exterior seismic wall and the
bearing interior seismic wall at the top level of the column; for Intensity 8, the ring-beams shall be also added in each 3~4m along height of the seismic wall. Depth of the ring-beam shall not be less than 180mm and its reinforcement shall not be less than 4 φ12. Foundation ring-beam shall also be installed, when the subsoil is weak cohesive soil, liquefaction-soil, newly-filled soil or a seriously non-uniformly distributed soil layer. When the ring-beam also serves as the lintel or resisting uneven-settlement, besides satisfying the above details of seismic design, its sectional dimension and reinforcements shall also be determined based on calculation for actual state. 9.3.13
A cast-in-situ reinforced concrete beam along the roof shall be installed at the gable seismic
wall and anchored with the roof components. The sectional area and reinforcements of the gable seismic wall columns should not be less than those of the bent frame column. The seismic wall columns shall be extended to the top of the gable and connected with the beam at the gable seismic wall or other roof components. 9.3.14
The ring-beam on top of the seismic wall or cushion block on top of the column shall be
connected firmly with roof truss (beam) through bolted connection or welded connection. Thickness of the cushion block on top of the column shall be no less than 240mm, and two layers of reinforcement mesh with a diameter of no less than 8mm and spacing no larger than 100mm shall be installed. The ring-beam on top of the seismic wall and the cushion block on top of the column shall be poured at the same time. 9.3.15
1
The structures of brick columns shall meet the following requirements: The brick Intensity Grade shall not be less than MU10, the Intensity Grade of mortar shall not 121
be less than M5; the concrete Intensity Grade for composite brick column shall be no less than C20. 2 9.3.16
The damp-proof course of the brick column shall adopt waterproof mortar. As for the brick-column factory buildings with reinforced concrete roofs, the horizontal
sectional area of gable opening should not exceed 50% of the total sectional area. For Intensity 8, reinforced concrete constructional columns (whose sectional dimension can adopt 240mm×240mm) shall be arranged at both sides of gables and transverse seismic wall. Vertical reinforcement shall not be less than 4 φ 12; hoops can adopt φ 6; space should be 250mm~300mm. 9.3.17
1
The structures of brick masonry seismic wall shall meet the following requirements: For brick column factory buildings with reinforced concrete roof without purlins of Intensity
8, 1φ8 vertical reinforcement should be embedded in each 1m along the length of the brick enclosure seismic wall and extended into ring-beam of the top of the seismic wall. 2
For the seismic wall top height is greater than 4.8m of Intensity 7 or for Intensity 8, at the
corner of the exterior seismic wall and the intersection of the bearing interior transverse seismic wall and the lengthwise outer seismic wall, 2φ6 reinforcements shall be installed every 500mm along the height of the seismic wall, and the length for each side extended into the seismic wall should not be less than 1m. 3
The details of seismic design for convex-type parapet shall meet relevant requirements in
Section 13.3 of this code.
10 10.1
Large-span Buildings Single-story Spacious Buildings
(Ⅰ) 10.1.1
General
The requirements of this Chapter shall be applied to public buildings consisting of spacious
single-story hall and attached buildings. 10.1.2
The seismic joint should not be installed between a hall and its ante-hall or stage, and also
may not be installed between a hall and its attached buildings on both sides, but their connection shall be strengthened. 10.1.3
The load-bearing structures for the hall of single-story specious buildings shall not adopt
brick columns in one of the following situations: 1
Halls for Intensity 7 (0.15g), Intensity 8 and 9.
2
There is cantilever platform in the hall.
3
For Intensity 7 (0.10g), hall span is larger than 12m or column top height is larger than 6m.
4
For Intensity 6, hall span is larger than 15m or column top height is larger than 8m.
10.1.4
The load-bearing structure of the roof at longitudinal seismic wall for the hall of single-story
spacious buildings, besides the requirements in Article 10.1.3, may also add composite seismic wall columns with reinforced concrete and brick at the supports of roof, but plain brick seismic wall columns must not be adopted. 122
10.1.5
The lateral rigidity in the transverse direction of the ante-hall shall be increased by the
structural component layout. The seismic wall columns around the gate and independent columns in the ante-hall shall adopt reinforced concrete columns. 10.1.6 The lateral rigidity of transverse seismic wall, which in the connection of the antehall and the
hall, as well as of the hall and the stage, shall be increased, and a certain number of reinforced concrete seismic wall shall be established. 10.1.7
For other requirements regarding the hall may refer to Chapter 9 of this code, and attached
buildings shall meet the relevant requirements in this code. (Ⅱ) 10.1.8
Essentials in Calculation
In seismic calculation of the single-story spacious buildings, which may be divided into
several separate units, such as the ante-hall, the stage, the hall, and attached buildings, than each unit calculated according to relevant structural system provisions in this code, but one another influence for those units shall be considered. 10.1.9
The seismic calculation for single-story spacious building may adopt the base shear method,
and the seismic influence coefficient may be taken as the maximum value. 10.1.10
The longitudinal horizontal earthquake action standard value of halls may be calculated
according to the following equation:
F EK =α maxG ep
(10.1.10)
Where,
F EK ——The standard value of longitudinal horizontal earthquake action on the longitudinal seismic wall or colonnade in one side of the hall;
G eq ——The equivalent gravity load representative value; it including the half of weight for the roof of hall, the half of weight for roof of adjacent attached buildings, 50% of the snow load standard value, and the reduction weight of the longitudinal seismic wall or colonnade in one side of hall. 10.1.11
1
The transversal seismic calculation for hall should meet the following principles: In case of hall without attached buildings on the two sides, the part with and without
cantilever platform may choose a typical bay for the calculation respectively; when the requirements in Chapter 9 of this code are satisfied, the s pace structural model may also be taken into consideration. 2
In case of hall with attached buildings on the two sides, proper calculation methods shall be
selected based on the structural types of the attached buildings. 10.1.12
The seismic checking of out-of-plane for the seismic wall columns of the tall gable shall be
carried out for Intensity 8 and 9. (Ⅲ)
Details of Seismic Design
10.1.13
The roof structures of the hall shall meet the requirements of Chapter 9 in this code.
10.1.14
The reinforced concrete column and composite brick-column of the hall shall meet the 123
following requirements: 1
The top of composite brick-columns vertical reinforcements shall be anchored into the
reinforced concrete ring-beam at the bottom of the roof truss. The longitudinal reinforcements of each side for the composite brick-column, besides to be determined by calculation, shall not be less than 4Φ14 for Intensity 6 with Site-category Ⅲ or Ⅳ and Intensity 7 (0.10g) with Site-category I or Ⅱ, and 4Φ16 for Intensity 7 (0.10g) with Site-category Ⅲ or Ⅳ. 2
The reinforced concrete column shall be designed according to frame columns no less than
Grade 2, and the reinforcement ratio shall be determined by calculation. The transversal seismic wall on the axis of the ante-hall with hall or the hall with stage shall
10.1.15
meet the following requirements: 1
The reinforced concrete frame columns or constructional columns shall be installed on the
two ends of the transverse seismic wall, the supports of longitudinal beams and both edges of large opening of the seismic wall. 2
Some transverse seismic wall that embedded in the frame columns shall be designed to
reinforced concrete seismic wall with no less than Grade 2 seismic Intensity. 3
The reinforced concrete structure shall be adopted for beam and columns of the stage opening.
For the bearing masonry seismic wall above the beam in the stage opening, the column with spacing no larger than 4m and ring-beams with spacing no larger than 3m shall be installed. And their sectional dimension, reinforcement ratio, and tie with the surrounding masonry seismic wall shall meet the requirements for multi-story masonry buildings. 4
Brick seismic wall on the beam in the stage opening shall not adopt light partition seismic
wall for Intensity 9. 10.1.16
A cast-in-situ ring-beam shall be installed at the top of the column (seismic wall) of the hall,
and an additional ring-beam shall be installed in each about 3m along the height of the seismic wall. For the trapezoidal roof truss with greater than 900mm end height, the additional ring-beam shall also be installed at the elevation of the top chord. The depth of ring-beam should be no less than 180mm, and width of ring-beam should be the same as thickness of the seismic wall, the longitudinal reinforcements should not be less than 4Φ12, and hoop spacing should not exceed 200mm. 10.1.17
When no seismic joint is installed between the hall and the attached buildings, a closed
ring-beam shall be installed at the same elevation and tied at the intersecting place of the hall and the attached buildings. And at the intersection of seismic wall, tie bars shall be installed in each 400mm along the height of the seismic wall, and the ties should extend into the seismic wall on both sides with length no less than lm. 10.1.18
The cantilever platform shall be reliably anchored, and measures shall be taken to prevent
its overturning. 10.1.19
The reinforced concrete beams along the roof shall be installed at the gable and shall be tied
with the roof components. The reinforced concrete columns or composite brick-columns shall be installed in the gable seismic wall; more, their sectional area and reinforcements should not be less than those of the bent frame column or composite brick-column in the longitudinal seismic wall respectively. These columns shall extend to the top of the gable and be connected with the beam on the gable. 124
10.1.20
The operation platform or storey shall be used as the horizontal brace of the tall gables,
which are the back seismic wall of the stage and the junction seismic wall of the hall and the ante-hall. 10.2
Large-span Roof Buildings
(Ⅰ) 10.2.1
General
This section is applicable to large-span steel roof buildings composed of arch, plane truss,
spatial truss, wire frame, reticulated shell, beam string structure and suspend-dome. As for the seismic design of large-span steel roof buildings adopting non-conventional type and whose span is larger than 120m, structural unit length is larger than 300m or cantilevered length is larger than 40m, special study and argumentation shall be carried out and effective reinforcement measures shall be adopted. 10.2.2
The type and arrangement of roofs and their bracing structures shall meet the following
requirements: 1
Shall be able to effectively transfer roof earthquake action to the lower bracing structures.
2
Shall be possessed of reasonable rigidity and bearing capacity distribution; arrangement of
roofs and their braces should be even and symmetrical. 3
Two space force transmission systems with balanced rigidity along horizontal direction
should firstly be adopted. 4
Structural arrangement should avoid forming weak positions, generating excessive internal
force and deformation concentration due to local weakening or mutation. As for weak positions that might appear, measures shall be adopted t o improve their seismic capacity. 5
Lightweight roof systems should be adopted.
6
Lower bracing structures shall be arranged reasonably to avoid generate excessive earthquake
torsional effects on roofs. 10.2.3
1
Structural arrangement of roofs shall respectively meet the following requirements: Structural arrangement of unidirectional force transmission system shall meet the following
requirements: 1)
Reliable braces shall be arranged among main structures (truss, arch and beam string
structure) to guarantee effective transmission of horizontal earthquake action along the direction that vertical to main structure; 2)
When lower chord joint bracing is adopted for the truss support, longitudinal trusses
shall be set among supports or other reliable measures shall be adopted to avoid torsion out of plane appear on the truss support. 2
Structural arrangement of space force transmission system shall meet the following
requirements: 1)
As for structures whose plane form is rectangular and three sides supporting one side
opening, the opening side shall be reinforced and ensured sufficient rigidity; 2)
Sealed horizontal bracing shall be set along peripheral supports for two-direction 125
orthogonal spatial wire frames and bi-directional beam string structures. 3)
Single-story reticulated shell shall adopt rigid connection joints.
Note: unidirectional force transmission system refers to plane arch, unidirectional plane truss, unidirectional spatial truss and unidirectional beam string structure, etc. Space force transmission system refers to wire frame, reticulated shell, bi-directional spatial truss, bi-directional beam string structure and suspend-dome, etc.
10.2.4
When roofs adopt different structural forms according to different areas, member bars and
joints in the border area shall be reinforced; seismic joints can be set, and joint width should not be less than 150mm. 10.2.5 Nonstructural components such as roof enclosure system, suspended ceiling and suspender
shall be reliably connected with structures, and their seismic measures shall meet the relevant requirements in Chapter 13 of this code. (Ⅱ) 10.2.6
Essentials in Calculation
As for the following roof structures, earthquake action calculation may not be carried out but
they shall meet the requirements of relevant seismic measures in this section: 1
For Intensity 7, as for unidirectional plane truss and unidirectional spatial truss whose
rise-span ratio is less than 1/5, earthquake action calculation along the horizontal and vertical direction of truss may not be carried out. 2 10.2.7
1
For Intensity 7, earthquake action calculation may not be carried out for grid structures. Seismic analysis calculation model of roof structures shall meet the following requirements: Calculation model shall be determined reasonably. Connection assumption between roofs and
main bracing positions shall be corresponding with structures. 2
The synergism of roof structure and substructure shall be counted in calculation model.
3
The earthquake action of bracing components in unidirectional force transmission system
should be calculated according to the integral model of roof structures. 4
The influence of geometrical rigidity should be counted in for the earthquake action
calculation model of beam string structures and suspend-domes. 10.2.8
In cooperative analysis of roof steel structure and lower bracing structure, damping ratio shall
meet the following requirements: 1
When the lower bracing structures are steel structures or roofs that directly support on ground,
damping ratio may be 0.02. 2
When lower supporting structures are concrete structures, damping ratio may be 0.025~0.035.
10.2.9
Horizontal earthquake action calculation of roof structures shall meet the following
requirements: 1
As for the unidirectional force transmission system, horizontal earthquake action can be
calculated respectively along main structure direction and direction that vertical to main structure. 2
For space force transmission system, horizontal earthquake action shall be calculated
simultaneously along at least two main shaft directions. As for roof structures with more than two 126
main shafts or obviously unsymmetrical quality and rigidity, the calculation direction of horizontal earthquake action shall be increased. 10.2.10
In general, mode-decomposition response spectrum method can be adopted for the frequent
earthquake action calculation of roof structures. As for complex structures or with large span, multi-directional earthquake response spectrum method or time history analysis method can also be adopted for supplementary calculation. As for peripheral bracing or combination of peripheral bracing and multi-point bracing regular wire frame, plane truss and spatial truss structures, simplified calculation can be carried out for their vertical earthquake action according to the requirements in Article 5.3.2 of this code. 10.2.11
Earthquake action effect combination of roof structural components shall meet the following
requirements: 1
As for the checking calculation of unidirectional force transmission system and main
structural components, the combination of horizontal earthquake effect along the direction of main structures and vertical earthquake effect can be adopted. As for the checking calculation of bracing components among main structures, only horizontal earthquake effect vertical to the direction of main structure can be counted in. 2
As for general structure, combination of three-dimensional earthquake action effects can be
carried out. 10.2.12
The combined deflection value of large-span roof structures under the gravity load
representative value and frequent vertical earthquake action standard value should not exceed the limit in Table 10.2.12.
Table
10.2.12
Deflection Limit of Large-span Roof Structures Cantilever structure
Structural system
Roof structure (short span
l 1 ) (cantilever span
Plane truss, spatial truss, wire fra me, beam string structure
l 1 /250
l 2 /125
Arch, single-story reticulated shell
l 1 /400
—
Double-story reticulated shell, suspend-dome
l 1 /300
l 2 /150
10.2.13
l 2 )
Seismic checking of roof component section shall not only meet relevant requirements in
Section 5.4 of this code but also shall meet the following requirements: 1
Seismic combination internal force design value of key member bars shall multiply by
enhancement coefficient, adopting 1.1, 1.15 and 1.2 for Intensity 7, 8 and 9 respectively. 2
Earthquake action effect combination design value of key joints shall multiply by
enhancement coefficient, adopting 1.15, 1.2 and 1.25 for Intensity 7, 8 and 9 respectively. 127
3
Inhaul cable in pretension structure shall not sag under frequent earthquake action.
Note: as for space force transmission system, key member bars refer to member bars close to the support, namely: chords and web members in 2 areas (grids) close to the support; chords and web members within the range of 1/10 span away from the support, adopting the smaller scope from them. As f or unidirectional force transmission system, key member bars refer to chords and web members in the section directly adjacent to the support. Key joints refer to joints connected with key member bars.
(Ⅲ) 10.2.14
Slenderness ratio of roof steel member bars should meet the requirements of Table 10.2.14:
Table
Slenderness Ratio Limit of Steel Member bars
Tension
Compression
Bending
Tension-bending
Common member bar
250
180
150
250
Key member bar
200
150(120)
150(120)
200
2
1
10.2.14
Type
Notes: 1
10.2.15
Details of Seismic Design
Values in the brackets are used for Intensity 8 and 9; The values in the above table are not applicable to flexible components such as inhaul cable.
Seismic structures of roof component joints shall meet the following requirements: When gusset plate is adopted to connect each member bar, the thickness of gusset plate
should not be less than 1.2 times of the maximum seismic wall thickness of connecting member bars. 2
When tubular joints are adopted, member bars on the direction with larger internal force shall
be through. The seismic wall thickness of through member bars shall not be less than that of each member bar welded on them. 3
When welded spherical joints are adopted, spherical seismic wall thickness shall not be less
than 1.3 times of the maximum seismic wall thickness of connected member bars. 4 10.2.16
1
Member bars should intersect at the center of joint. Seismic structures of supports shall meet the following requirements: Shall be possessed of sufficient strength and rigidity, shall not damage before member bars
and other joints under the action of loads, must not generate unneglected deformation. The structural forms of support joints shall reliably transfer force, be connected simply and meet the calculation assumption. 2
As for horizontal slideable support, the roof sliding shall not exceed the supporting surface
under rare earthquake, and limit measures shall be adopted. 3
For Intensity 8 and 9, support only bearing vertical pressure under frequent earthquake should
adopt tension-compression type. 10.2.17
When roof structures adopt seismically-isolated and shock-absorption supports, their
performance parameters, durability and relevant structures shall meet relevant requirements in Chapter 12 of this code.
128
11
Earth, Wood and Stone Houses 11.1
General
Constructional and structural layout of earth, wood and stone houses shall meet the following
11.1.1
requirements: 1
Housing plane layout shall avoid corners or highlights.
2
Arrangement of vertical and horizontalbearing seismic wall should be uniform, symmetrical,
aligned
in
the
plane
and
up-and-down
continuous
along
vertical
direction;
width
of
between-two-windows seismic wall should be uniform at the same axis. 3
The storeys of multi-storey building shall not be split-level, in addition, plate and single side
suspended staircase shall not be adopted. 4
Bracing components with different materials shall not be adopted within the same height.
5
Masonry shall not be laid on the outrigger outside eave.
11.1.2
1
Tie measures shall be taken in the following positions for wood storey and roof houses: Vertical diagonal brace shall be arranged for both-end bay roof truss and medially separated
room roof truss; 2
Along-full-length level tie bars shall be arranged in longitudinal direction at eave height;
those tie bars shall be connected with each cross seismic wall with seismic wall cables or those tie bars shall be connected firmly with wooden beam and the bottom chord of roof truss. The end of vertical tie bar should be butted with wooden splint and the seismic wall cable may be such materials as rectangular timber and angle iron; 3
Gable and pediment shall be tied with wooden truss, timber frame or purline by using seismic
wall cable; 4 11.1.3
Internally-seperated seismic wall top shall be tied with beam or bottom chord of roof truss. Bracing length of wood storey and roof components shall not be less than those specified in
Table 11.1.3: Table 11.1.3: Minimum Bracing Length of Wood Storey and Roof Components (mm) Wooden truss and Component name
Overlapped rough ground and Butted rough ground and wooden purlin bar
wooden beam Position
On seismic wall
wooden purlin bar On roof truss
Bracing length and
On seismic wall 120 (Wood splint and
240 (Timber foot block) 60 (Wood splint and bolt) connection mode
11.1.4
On roof truss and seismic wall
Full overlapping bolt)
Bracing length of lintel at door and window opening shall not be less than 240mm for
Intensity 6~8 and it shall not be less than 360mm for Intensity 9. 11.1.5
When cool-spreading tile roof is adopted, tack hole should be arranged at the two corners of
under-tile arc edge so that the tile roof may be fixed firmly with rafter with iron nail; lime or cement mortar rolling methods should be adopted for bonding firmly the cover tile and under tile. 129
11.1.6
Out roof height of such collapsing components as the out-roof chimney and parapet of earth,
wood and stone houses shall not be greater than 600mm for Intensity 6 and 7; it shall not be greater than 500mm for Intensity 8 (0.20g) and not be greater than 400mm for Intensity 8 (0.30g) and 9. In addition, tying measures shall be taken. Note: Height of chimney on pitched roof shall be calculated from chimney foot.
11.1.7
Structural materials of earth, wood and stone houses shall meet the following requirements:
1
Wood component shall be made of these dry woods with straight grains and little knots.
2
Earth for immature earth seismic wall shall be cohesive soil with little impurity.
3
Stones shall be solid and free from efflorescence, de-lamination or crack.
11.1.8
Construction of earth, wood and stone houses shall meet the following requirements:
1
180º hook shall be arranged at the end of HPB 300 reinforcement.
2
Rust prevention treatments shall be carried out for exposed ironworks. 11.2
11.2.1
Unfired Earth Houses
This section is applicable to Intensity 6 and 7 (0.10g) houses, earth cave dwelling and earth
arch house with unfired adobe, lime soil and rammed bearing seismic wal l. Note: 1 lime soil seismic wall refers to earth seismic wall and lime adobe seismic wall with lime (or other binding materials); 2 Earth cave dwelling refers to the cliff kiln being excavated in un-disturbed raw soil.
11.2.2
Height and bearing cross seismic wall interval of unfired earth houses shall meet the
following requirements: 1
Unfired earth houses should be constructed into single storey; lime soil seismic wall houses
may be constructed into two storeys but the total height shall not be greater than 6m. 2
Cornice height of single-storey unfired earth house should not be greater than 2.5m.
3
Bearing cross seismic wall spacing of single-storey unfired earth houses should not be greater
than 3.2m. 4 11.2.3
Clear span of cave dwelling should not be greater than 2.5m. Roofs of unfired earth houses shall meet the following requirements:
1
To adopt light roofing materials;
2
Purlin roof should be double pitched roof or curve roof and crosser shall be arranged at purlin
brace; end purlin shall be out the eave and the purlin on inner seismic wall shall be fully overlapped or butted with splint or connected with dovetail tenon and clasp nail together. 3
Wire nail, clasp nail and steel wire etc. shall be adopted to connect all components of wooden
roof. 4
Wooden truss and wooden beam should be fully overlapped on the outer seismic wall. At
support, wood ring beam or wood sub-plate shall be arranged; the length, width and thickness of those 130
wood sub-plates should not be less than 500mm, 370mm, 60mm respectively; in addition, mortar bed or clay-stone mortar under layer shall be laid under sub-plate. Bearing seismic wall of unfired earth houses shall meet the following requirements:
11.2.4
1
Width of door and window openings of bearing seismic wall shall not be greater than 1.5m
for Intensity 6 and 7. 2
Wood lintels should be adopted for door and window opening; when lintel consists of several
wooden poles, all wooden poles should be connected into an integral with wood plate, clasp nail and lead wire etc. 3
Internal and external seismic wall shall be rammed or laid in stagger layer by layer and
simultaneously. At four corners of outer seismic wall as well as the intersection of internal and external seismic wall, one layer of tie mesh knitted with such materials as bamboo reinforcement, batten or twigs of the chaste tree shall be laid about every other 500mm along seismic wall height; each edge shall not be less than 1000mm stretching into seismic wall or the edge shall stretch to the edge of door and window opening; in addition, tie mesh shall be banded at the intersection or other measures to strengthen the integrity shall be taken. 11.2.5
Sub-Grades of various unfired earth houses shall be tamped; such foundations shall be made
of hewn stones, slab-stones, chiseled cobble stones or common bricks; and foundation seismic wall shall be laid with composite mortar or cement mortar. Dado moisture-proof treatment should be conducted for outer seismic wall (moisture barrier should be arranged at the seismic wall foundation). 11.2.6
Adobe should be formed with cohesive-soil wet process and it shall be mixed with such tying
materials as grass or reed; adobe shall be laid in recumbent position and it shall be laid with clay motar or clay stone mortar. 11.2.7
Ring beams shall be arranged for each storey of lime soil seismic wall house which shall be
pulled through on cross seismic wall; two step piers should be added at both sides of pediment for longitudinal seismic wall top. 11.2.8
Several spans of earth arch house shall be connected; each arch springing shall be supported
on steady cliff or artificial earth seismic wall; arch ring thickness should be 300mm~400mm; formwork masonry shall be taken in stead of retroversion adhering ion laying; door and window shall not be arranged on the outside bracing seismic wall and arch ring. 11.2.9
Earth cave dwelling shall be away from those areas with landslide and landslip; cliff for
excavating cave dwelling shall be endowed with compact and stable soil, gentle slope and no obvious vertical joint; front seismic wall of adobe or other materials should not be laid before cliff cave; storey-cave should not be excavated, otherwise adequate space shall be maintained and the up and down shall be not aligned. 11.3 11.3.1
Wood Houses
This section is applicable to Intensity 6~9 houses with column-and-tie wooden frame, wood
column truss and wood column beam. 11.3.2
Wood houses shall not be supported by wood column and brick column (or brick seismic wall)
together; end roof truss (wooden beam) shall be arranged for gable while purlin roof shall not be adopted. 131
11.3.3
1
Height of wood houses shall meet the following requirements: When the Intensity is 6~8, Wood column truss and column-and-tie wood frame houses should
not be greater than two storeys and the total height should not be greater than 6m; when the Intensity is 9, these houses shall be single storey and the height shall not be greater than 3.3m. 2
Wood column beam houses should be constructed into single storey and the height should not
be greater than 3m. 11.3.4
Three-span wood bent with four columns grounding shall be adopted for such spacious
buildings with great span as assembly hall, showplace and granary. 11.3.5
Supporting arrangement of wooden truss roof shall meet the relevant provisions and
requirements stated in Section 9.3 of this code; while the roof truss braces at house two ends shall be arranged in end bay. 11.3.6
column
Diagonal braces shall be arranged between wood column and roof truss (or beam) for wood truss
and
wood
column
beam
houses;
diagonal
braces
shall
be
arranged
in
non-seismically-insulated seismic wall for dwelling houses with several cross seismic wall; diagonal brace should be wood splint which shall lead to the upper chord of roof truss. 11.3.7
Tie-beams shall be arranged at both upper and lower column ends and bottom storey at
transverse and longitudinal directions of column-and-tie wood frame house; in addition, 1~2 shear brace or diagonal brace shall be arranged between each longitudinal colonnade space. 11.3.8
1
Connections of wood house components shall meet the following requirements: Concealed dovetail at column top shall be inserted into the bottom chord of roof truss and the
column top shall be connected with U-irons; when the Intensity is 8 or 9, column base shall be anchored with foundation with ironworks or by other measures. Depth of column base embedded into ground shall not be less than 200mm. 2
Both diagonal brace and roof brace structure shall be connected with main component with
bolts; except column-and-tie wood component, other wood components should be connected with bolts. 3
Rafter and purlin shall be nailed completely for overlapping in order to strengthen roof
integrity. In wooden frame, vertical diagonal brace shall be arranged above column cornice and long house longitudinal direction so as to reinforce longitudinal stability. 11.3.9
Wood components shall meet the following requirements:
1 Top diameter of wood column should not be less than 150mm; simultaneous grooving at both vertical and horizontal directions of the same column height shall be avoided; what's more, the grooving area in the same column section shall not be greater than 1/2 total section area. 2 Columns shall be free from any joints. 3 Tie-beams shall go through all columns of wooden frame. 11.3.10
1
Enclosure seismic wall shall meet the following requirements: Tying of enclosure seismic wall and wood column shall meet the following requirements: 1)
Level tie bars or tie meshes in the seismic wall should be tied with wood column with 132
No. 8 steel wire about every other 500mm along seismic wall height. 2)
Reinforcement brick ring beam, reinforcement mortar strip and wood column shall be
tied with φ6 steel bar for Grade 8 steel wire. 2
As for enclosure seismic wall laid with adobes, the opening width shall meet the
requirements stated in Section 11.2 of this code. As for those enclosure seismic wall laid with bricks and etc., widths of these openings in the cross seismic wall and inner longitudinal seismic wall should not be greater than 1.5m; and the widths of the openings on outer longitudinal seismic wall should not be greater than 1.8m or half bay dimension. 3
Enclosure seismic wall laid with adobe or brick and etc. shall not envelop wood column
completely, instead, it shall laid close to wood column outside. 11.4 11.4.1
Stone Houses
This section is applicable to Intensity 6~8 houses bore with dressed stone masonry laid with
mortar (including with gasket or without gasket). 11.4.2
Total height and storeys number of multi-storey stone masonry houses shall not be greater
than those ones specified in Table 11.4.2.
Table 11.4.2: Total Height (m) and Storeys Number Limit of Multi-storey Stone Masonry Houses Intensity Seismic wall type
6
7
8
Height
Storeys
Height
Storeys
Height
Storeys
Fine, half fine stone masonry (without gasket)
16
5
13
4
10
3
Rubble ashlar and rubble masonry (with gasket)
13
4
10
3
7
2
Notes: 1 Calculation of house total height is the same with the one noted for Table 7.1.2 of this code. 2 For houses with a few transverse seismic wall, the total height shall be reduced by 3m and the storeys shall be reduced by one correspondingly.
11.4.3
Storey height of houses with several-storey stone masonry should not be greater than 3m.
11.4.4
Seismic cross seismic wall space of multi-storey stone masonry house shall not be greater
than the one listed in Table 11.4.4.
Table 11.4.4: Seismic Cross Seismic wa ll Space (m) of Multi-storey Stone Masonry Houses Intensity Storey and roof type 6
7
8
Cast-in-situ and assembling integral reinforced concrete
10
10
7
Assembling reinforced concrete
7
7
4
133
11.4.5
For multi-storey multi-storey stone masonry house, cast-in-situ or assembling integral reinforced reinforced concrete
storey or roof should be adopted. 11.4.6
Seismic check of stone seismic wall section may refer to Section 7.2 of this code; and and the
shear strength of such stone seismic wall shall be determined by test data. 11.4.7
Reinforced concrete columns shall be arranged at outer-seismic wall four corners, staircase
four corners and at the internal and external seismic wall intersection of each bay for those multi-storey stone masonry houses. 11.4.8
Horizontal section area of seismic cross seismic wall opening shall not be greater than 1/3
total cross section area. 11.4.9
Ring beams shall be arranged arranged for both vertical and horizontal horizontal seismic wall of each storey.
Thereof the section height shall not be less than 120mm, the width should be same with seismic wall thickness; longitudinal reinforcement shall not be less than 4 φ10 and stirrup spacing should not be greater than 200mm. 11.4.10
The intersection of vertical and horizontal seismic wall of structural columns shall be laid
with strip stones but without gasket; in addition, tie reinforcing mesh sheet shall be arranged every other 500mm along seismic wall height and the sheet length stretching into seismic wall at each edge and each side should not be less than 1m. 11.4.11
Slabs shall not be adopted as bearing components.
11.4.12
Other requirements for relevant aseismic structural measures refer to those specified in
Chapter 7 of this code.
12
Seismically-isolated and Energy-Dissipated Buildings 12.1
12.1.1
General
The requirements requirements of this chapter shall be applied to designs for seismically-isolated buildings
that set up a seismically-isolated layer to isolate ground motion, as well as to designs for energy-dissipated buildings that set up energy-dissipated components to absorb and dissipate the earthquake energy. The seismically-isolated and energy-dissipated building structures shall meet the requirements in Article 3.8.1 of this code, and the seismic precautionary objectives shall meet the requirements in Article 3.8.2 of this code. Notes: 1
The design of seismically-isolated building in this chapter re fers to the seismically-isolated layer, which consists of the
rubber seismically-isolated support and the damper etc., established at the foundation, bottom or substructure and superstructure of the building. The purpose purpose for establishing establishing the layer is to increase the natural natural vibration period, reduce reduce the horizontal earthquake earthquake action introduced to the superstructure, and satisfy the expected seismic requirements. 2
The design of energy-dissipated energy-dissipated building building refers to installment energy-dissipated energy-dissipated components, components, which can provide provide additional
damping by partial deformation and relative speed, to dissipate the seismic energy, which introduced to the structure, and satisfy the expected seismic requirements.
12.1.2
When seismically-isolated design and energy-dissipated design of building structures are 134
determined, not only the requirements in Article 3.5.1 of this code shall be met, but also the contrastive analysis shall be carried out with the adopted seismic design scheme. 12.1.3
When the building structures adopt seismically-isolated design, the following requirements
shall be met: 1
The structural aspect ratio should should be less than 4 and shall not not be larger larger than the concrete
requirements of relevant codes and regulations to non-seismically-isolated structures. The deformation characteristics shall approach shearing deformation. The maximum height shall meet the requirements for non-seismically-isolated structures in this code. Special study shall be carried out for structures whose aspect ratio is larger than 4 or non-seismically-isolated structures, when they adopt seismically-isolated design. 2
The buildings with Site-category assigned to I, II or III; and the stable foundation types shall
also be selected. 3
The total horizontal force produced by wind load and other non-earthquake action shall not
exceed 10% of the total structural gravity. 4
The seismically-isolated layer shall possess necessary load bearing capacity, lateral rigidity
and damping; the pipelines and circuits of equipment crossing the seismically-isolated layer shall adopt flexible connection and other effective measures to withstand the horizontal displacement during rare earthquakes. 12.1.4
Energy-dissipated design design can be used in the steel, reinforced concrete and steel-reinforced
concrete building structures. The energy-dissipated components shall be able to provide sufficient additional damping, and shall respectively meet the requirements of corresponding structural types for the requirements in this code. 12.1.5
For
the
design
of
seismically-isolated
and
energy-dissipated
buildings,
the
seismically-isolated units and energy-dissipated devices shall meet the following requirements: 1
The durability and the design parameters of the seismically-isolated units and
energy-dissipated devices shall be determined by testing. 2
The location installed seismically-isolated units and energy-dissipated energy-dissipated devices, measures for
the convenience of check and renewal shall also be taken. 3
The property property requirements requirements for for seismically-isolated units and energy-dissipated devices shall
be stated clearly in the design document. Inspection shall be carried out as required before installation to make sure their performances meet the requirements. 12.1.6
The designs of seismically-isolated and energy-dissipated buildings shall also meet the
requirements of corresponding specification. Performance-based design can be carried out according to the requirements of seismic performance objectives. 12.2 12.2.1
Essentials in Design of Seismically-isolated Buildings
The design of seismically-isolated buildings shall select appropriate seismically-isolated
layer consisted of the seismically-isolated units and wind-resisting units, based on the expected vertical bearing capacity, horizontal shock-absorption coefficient and the requirements for seismic 135
displacement control. The load bearing capacity check and horizontal displacement check under rare earthquake shall be carried out for the seismically-isolated units. The horizontal earthquake action of structures above the seismically-isolated layer shall be determined according to the horizontal shock-absorption coefficient. The standard values of vertical earthquake action for that shall not be less than 20%, 30% and 40% of the total gravity load representing values of the structure above the seismically-isolated layer for Intensity 8 (0.20g) 8 (0.30g) and 9. 12.2.2
The calculation analysis of design of seismically-isolated building structures shall meet the
following requirements: 1
As for the calculation sketch of seismically-isolated system, the mass points composed composed of the
seismically-isolated support and the top beam slabs shall be added. The structures with shear-type deformation characteristics may adopt the shear type model (Figure12.2.2). When the centroid of the structure above the seismically-isolated layer and the rigidity center of the seismically-isolated layer do not coincide, the influence of torsion deformation shall be taken into consideration. For the beam-slab structures above the seismically-isolated layer shall be deemed as a part of the superstructure for calculation and design.
Figure12.2.2
2
Calculation Sketch for Seismically-isolated Structure
In general, time history analysis analysis method should be adopted for calculation. The response
spectrum characteristics and amount of input seismic waves shall meet the requirements of Article 5.1.2 in this code. The calculated results should adopt their envelope values. When within 10km in seismogenic fault, near-field influence coefficient shall be considered for input seismic waves; it should adopt 1.5 within 5km; it can adopt no less than 1.25 out of 5km. 3
Masonry structures and structures similar to its foundational period may may carry out simplified
calculation according to Appendix L of this code. 12.2.3
1
The rubber rubber supports supports in the seismically-isolated layer shall meet the following requirements: requirements: The ultimate horizontal displacement of the rubber supports supports under the compressive stress of
provided in Table Table 12.2.3 shall exceed 0.55 times its effective diameter or 3 times of the t otal thickness 136
of all rubber layers, whichever is greater. 2
After passing the durability tests of corresponding design live, the rigidity and damping
characteristics changes of the supports shall not exceed ±20% of the primary stage values, the creep shall not exceed 5% of the total thickness of all rubber layers. 3
The average compressive stress design values of all rubber supports shall not exceed the
requirements in Table 12.2.3.
Table
12.2.3
Notes: 1
Limit Values of the Average Average Compressive Compressive stress for Rubber Seismically-isolated Supports Building category
A
B
C
Limit Limit values values of the average average compressi compressive ve stress stress (MPa)
10
12
15
The average compressive stress design value shall be calculated according to the combination of the permanent load and
variable load. Therein, floor live loads shall multiply by reduction coefficient according to the requirements of the current national standard “load code for design of building structures” GB 50009. 2
For structures that need to check check overturning, the the horizontal earthquake action action combination shall also be taken into
consideration; for structures that need to calculate the vertical earthquake action, the vertical earthquake action combination shall also be taken into consideration; consideration; 3
When the secondary form-factor (ratio of effective diameter diameter to the total thickness thickness of rubber layer) layer) of the rubber
seismically-isolated support is less than 5.0, the limit value of average compressive stress shall be reduced as follows: for less than 5 but no less than 4, reduce reduce by 20%; for less than than 4 but no less than 3, 3, reduce by 40%; 4
As for the rubber support support whose outside diameter diameter is less than 300mm, 300mm, the compressive compressive stress limit value value of Class-C
buildings is 10MPa. 10MPa.
12.2.4
The arrangement, arrangement, vertical bearing capacity, lateral rigidity and damping damping of of the
seismically-isolated layer shall meet the following requirements: 1
The seismically-isolated layer should be installed at the bottom or lower parts of the structure.
The rubber support shall be placed at locations where the interior forces are greater, the spacing should not be too large; the size, amount and distribution shall be determined according to the requirements of the vertical bearing capacity, the lateral rigidity and the damping. The seismically-isolated layer shall be stabilized under rare earthquake, and should not have non-restorable deformations. When the rubber support is under the horizontal and vertical earthquake actions of rare earthquakes, tensile stress shall not be larger than 1 MPa. 2
The horizontal horizontal equivalent rigidity and equivalent damping damping ratio may be calculated according
to the following formulae:
K h = ζ ep = Where,
∑ K
(12.2.4-1)
j
∑ K ζ / K j
j
h
(12.2.4-2)
ζ ep ——The equivalent damping ratio of the seismically-isolated layer; 137
K h ——The horizontal equivalent rigidity of the seismically-isolated layer; ζ j ——The equivalent damping ratio of the j-th seismically-isolated support determined by testing; when damper is installed, corresponding damping ratio of the damper shall included;
K j ——The horizontal equivalent rigidity of the j-th seismically-isolated support determined by testing. 3
When the design parameters of seismically-isolated support are determined through tests, the
vertical loads shall keep the compressive stress limit values specified in Table 12.2.3 of this code. As for
the
calculation
of
horizontal
shock-absorption
coefficient,
equivalent-rigidity
and
equivalent-viscosity damping ratio with 100% shearing deformation shall be adopted. As for the checking calculation of rare earthquake, equivalent-rigidity and equivalent-viscosity damping ratio in 250% shearing deformation should be adopted. When the diameter of seismically-isolated support is larger, equivalent-rigidity and equivalent-viscosity damping ratio in 100% shearing deformation shall be adopted. When time history analysis is adopted, hysteretic curves obtained from tests shall be used as the calculation basis. The calculation of earthquake action for structures above the seismically-isolated layer shall
12.2.5
meet the following requirements: 1
For multi-story structures, horizontal earthquake actions can be distributed according to
gravity load representative values along the height. 2
Seismically-isolated horizontal earthquake influence coefficient of horizontal earthquake
action can be determined according to Article 5.1.4 and Article 5.1.5 of this code. Therein, the maximum horizontal earthquake influence coefficient may be calculated according to following formula:
α max1 = βα max/ Where,
(12.2.5)
α max1 ——The maximum seismically-isolated horizontal earthquake influence coefficient; α max ——The maximum non-seismically-isolated horizontal earthquake influence
coefficient can be adopted according to Article 5.1.4 of t his code;
β ——The horizontal shock-absorption coefficient; as for multi-story buildings, it is the maximum ratio of inter-storey shears in each seismically-isolated and non-seismically-isolated layer obtained according to elastic calculation. As for highrise structure, the maximum ratio of overturning moment in each seismically-isolated and non-seismically-isolated layer shall be calculated, which shall be compared with the maximum ratio of inter-storey shear, and the larger value shall be adopted. ——The adjustment coefficient; as for general rubber support, 0.80; as for Class S-A support shearing performance deviation, 0.85; as for seismically-isolated devices with damper, 138
decreasing by 0.05 correspondingly. Notes: 1
In simplified calculation and response spectrum analysis, elastic calculation should be calculated according to the
performance parameters in 100% seismically-isolated support horizontal shear strain; when time history analysis method is adopted, calculation shall be carried out according to the design basic seismic acceleration input; 2
Support shearing performance performance deviation shall shall be determined according according to the current national national standard “Rubber “Rubber Bearing -
Part 3: Elastomeric seismic-protection isolators for buildings” GB 20688.3. 3
The total horizontal earthquake earthquake action of structures above above seismically-isolated seismically-isolated layer must not be less than that of
non-seismically-isolated structures when precautionary for Intensity 6, and seismic checking shall be carried out for it. The horizontal earthquake shear force of each story shall meet the requirements of Article 5.2.5 in this code for the minimum earthquake shear coefficient of that regional precautionary Intensity. 4
For Intensity 9, and Intensity 8 with no larger larger than 0.3 shock-absorption shock-absorption coefficient along horizontal horizontal direction, vertical
earthquake action calculation shall be carried out for structures above seismically-isolated layer. layer. When calculating vertical earthquake action standard values of structures above seismically-isolated layer, each layer can be regarded as mass point, and the distribution of vertical earthquake action standard value along height shall be calculated according to Formula (5.3.1-2) of this code.
12.2.6
The shear force of the seismically-isolated support support shall be distributed according to the
horizontal rigidity of all seismically-isolated supports from which is the horizontal shear force of the seismically-isolated layer under the rare earthquake. When calculation considered to torsion, the torsion rigidity of the seismically-isolated layer shall be taken into consideration. The horizontal displacement of the seismically-isolated support corresponding to the horizontal shear under the rare earthquake shall meet the following requirements:
Where,
u i ≤[ u i ]
(12.2.6-1)
u i =η i u c
(12.2.6-2)
u i ——The horizontal displacement of i-th seismically-isolated support when taking into
account of the torsion under the rare earthquakes; [ u i ]——The limit value of horizontal displacement of i-th seismically-isolated support, in the case of rubber seismically-isolated support, it shall not exceed 0.55 times of the effective diameter of the support or 3 times of the total thickness of all rubber layers, whichever is smaller;
u c ——The horizontal displacement at the centroid of the seismically-isolated layer under rare earthquakes, which the torsion is not taken into consideration;
η i ——The torsion influence coefficient of i-th seismically-isolated support, the ratio of the calculated displacements of i-th support with regard to and without regard to torsion shall be taken into consideration. When the centroid of the structure above the seismically-isolated layer and the rigidity center of the seismically-isolated layer are not eccentric in both main axial directions, the torsion influence coefficient of the side support shall not be less than 1.15. 139
12.2.7
The seismically-isolated measures of of the seismically-isolated structures shall meet the
following requirements: 1
The
follow
measures
which
will
not
disturb
significant
deformation
of
the
seismically-isolated layer under rare earthquake shall be adopted: 1)
Vertical separating joints shall be arranged on the periphery of superstructure. The joint
width should not be less than 1.2 times of the maximum horizontal displacement of each seismically-isolated support under rare earthquake and should not be less than 200mm. As for two adjacent seismically-isolated structures, the joint width shall take the sum of maximum horizontal displacement and shall not be less than 400mm. 2)
Between superstructure superstructure and substructure, full-length full-length horizontal horizontal isolating joints shall be
arranged and filled with flexible materials; the joint height can adopt 20mm.When it is difficult to arrange horizontal isolating joints, reliable horizontal sliding under layer shall be arranged. 3)
In location such as the corridors, the staircase, the elevators, and lanes etc., any possible
collision shall be prevented. 2
As for the seismic measures measures of structures above seismically-isolated layer, when the
horizontal shock-absorption coefficient is larger than 0.40 (0.38 when damper is arranged), requirements
related
to
non-seismically-isolated
shall
not
be
reduced.
When
horizontal
shock-absorption coefficient is no larger than 0.40 (0.38 when damper is arranged), the requirements for non-seismically-isolated buildings in relevant chapters of this code can be reduced properly, but Intensity decrease must not exceed 1 degree, as well as details of seismic design related to resisting vertical earthquake action shall not be reduced. At this time, as for masonry structure, details of seismic design can be adopted according to Appendix L of this code. Note: seismic measures related to resisting vertical earthquake action, refer to axial force ratio requirements of seismic wall and columns for reinforced concrete structures; refer to requirements related to the minimum size of exterior seismic wall end seismic wall and ring beams for masonry structures.
12.2.8
The connection connection between the seismically-isolated layer and the structure above the
seismically-isolated layer shall meet the following requirements: 1
Beam-slab type floor shall be installed on on top of the seismically-isolated layer, layer, and shall meet
the following requirements: 1)
Relevant positions positions of seismically-isolated supports shall adopt adopt cast-in-situ concrete
beam and slab structures. Cast-in-situ slab thickness shall not be less than 160mm; 2)
The rigidity and the bearing capacity of of the beams and and slabs on the top of the
seismically-isolated layer should be larger than the rigidity and bearing capacity of ordinary beams and slabs; 3)
Beams and columns near the seismically-isolated support support shall checking the
punching-shear and local-compression capacity, the hoops shall be densified and mesh reinforcements shall be installed if necessary. 2
The connected structures of the seismically-isolated support and and the damper shall meet the
following requirements: 1)
The support and the damper shall be installed in locations where the maintenance 140
personnel can access easily; 2)
The connecting connecting pieces of the seismically-isolated support with the superstructure and and
substructure shall be able to transfer the maximum horizontal shear force and bending moment of the support under rare earthquake; 3)
Exposed embedded parts shall have reliable anti-rust treatment. The The anchoring anchoring
reinforcement of the embedded parts shall be connected to t he steel plate firmly. The anchorage length of anchorage reinforcement should be larger than 20 times of is diameter and shall not be less than 250mm. Structures and foundation below seismically-isolated layer shall meet the following following
12.2.9
requirements: 1
As for buttress, column and connecting components in seismically-isolated layer, layer, bearing
capacity checking calculation shall be carried out by adopting vertical force, horizontal force and moment at the bottom of support of seismically-isolated structure under rare earthquake. 2
Relevant components directly bearing structures above seismically-isolated layer in structures
below seismically-isolated layer (including basement and chassis below seismically-isolated tower) shall meet embedded rigidity ratio and seismic bearing capacity requirements of seismically-isolated precautionary earthquake, and shear capacity checking calculation shall carried out for them according to rare earthquake. Inter-story drift angle limit of structures below seis mically-isolated layer and above ground under rare earthquake shall meet the requirements in Table 12.2.9. 3
Seismic checking and subsoil subsoil treatment for seismically-isolated building subsoil foundation foundation
shall be carried out according to the regional seismic precautionary Intensity. Anti-liquefaction measures of Class A and B buildings shall be determined by improving one liquefaction Grade until eliminating all liquefaction subsidence.
Table
12.2.9
Inter-storey Elastoplastic Drift Angle Limit Limit of Structures Below Seismically-isolated Seismically-isolated Layer and and Above Ground Under Rare Earthquake Action
12.3 12.3.1
Substructure types
[ θ p ]
Reinforced concrete frame structure and steel structure
1/100
Reinforced concrete Frame-seismic wall
1/200
Reinforced concrete seismic wall
1/250
Essentials in Design of Energy-dissipated Buildings
For the energy-dissipated buildings, the proper energy-dissipated energy-dissipated components components shall be
installed according to the expected shock-absorption requirements under frequent earthquakes and expected
structural
displacement
controlling
requirements
under
rare
earthquake.
The
energy-dissipated components may be consisted of the energy-dissipated device as well as the supporting components such as diagonal brace, the seismic wall and the beam. The energy-dissipated device may adopt the speed-related type, the displacement-related type or other types. 141
Notes: 1
The speed-related type energy-dissipated energy-dissipated device refers to the viscous energy-dissipated energy-dissipated device and viscoelastic
energy-dissipated energy-dissipated device etc. 2
The displacement-related type type energy-dissipated energy-dissipated device refers to metal yielding energy-dissipated energy-dissipated device and frictional frictional
energy-dissipated energy-dissipated device etc.
12.3.2
The energy-dissipated energy-dissipated components may be installed along the two main main axis of the structure
respectively if necessary. The energy-dissipated components shall be installed at locations where the deformation is significant, its number and distribution shall be determined according to comprehensive analysis, and shall be favorable for increasing the energy-dissipated capacity and for composing an even and reasonable forcing system of the whole structure. 12.3.3
The calculating analysis of the energy-dissipated energy-dissipated building building structures shall meet the following
requirements: 1
When main structures are basically at the elastic working working stage, simplified estimation with
linear analysis method can be adopted, with the structural deformation characteristics and height, base shear method, mode-decomposition response spectrum method and time history analysis method can be adopted respectively according to the requirements in Section 5.1 of this code. Seismic S eismic influence coefficient of energy-dissipated structures can be adopted with regard to total damping ratio according to the requirements in Article 5.1.5 of this code. The natural vibration period of energy-dissipated structures shall be determined according to the total rigidity of energy-dissipated structures; total rigidity shall be sum of structural rigidity and effective rigidity of energy-dissipated components. The total damping ratio of energy-dissipated structures shall be the sum of structural damping ratio and effective damping ratio of energy-dissipated components applying on structures. Total damping ratio under frequent earthquake and rare earthquake shall be calculated respectively. 2
When main main structures enters into elastoplastic stage, static force nonlinear analysis analysis method or
nonlinear time history analysis method shall be adopted according to the architectural features of main structures. In the nonlinear analysis, the resilience model of energy-dissipated structures shall include structural resilience model and energy-dissipated component resilience model. 3
The inter-storey inter-storey elastoplastic displacement angle angle limit of energy-dissipated energy-dissipated structures shall
meet the requirements of prospective deformation control and should be reduced properly compared with energy-dissipated structures. 12.3.4
The effective effective damping ratio and effective rigidity added to the structure by energy-dissipated
components may be determined according to the following methods: 1
The effective effective rigidity applied on structures by displacement-related energy-dissipated
components and nonlinear-speed-related energy-dissipated components shall be determined with equivalent linearization method. 2
The effective effective damping damping ratio added by the energy-dissipated energy-dissipated components, components, may be estimated
according to the following equation:
ξ a =
/ 4π W ） ∑W （ cj
s
(12.3.4-1)
j
142
Where,
ξ a ——The effective damping ratio added by the energy-dissipated components; W cj ——The energy consumed by j th energy-dissipated components recirculating one
cycle under displacement
Δ u j in the structural expected layer;
W s ——The total strain energy of energy-dissipated structures under expected displacement. Note: when the energy-dissipated components are evenly distributed on structures and effective damping ratio applied on structures are less than 20%, the effective damping ratio of energy-dissipated components on structures can be determined through compulsive discoupling method.
3
When the torsion effect is not taken into consideration, the total strain energy of the
energy-dissipated structure under horizontal earthquake action may be estimated according to the following equation:
W s =(1/2)
∑ F u i
i
(12.3.4-2)
Where, F i ——The horizontal earthquake action standard value of i-th mass point;
u i ——The displacement of i-th mass point corresponding to horizontal earthquake action standard value. 4
The energy dissipated by the speed-linear-relevant type energy-dissipated device under
horizontal earthquake action may be estimated according to the following equation:
W cj=（2π 2 /T 1）C j cos 2 θ jΔu j2 Where,
(12.3.4-3)
T 1 ——The foundational natural vibration period of the energy-dissipated structure; C j ——The linear damping factor of the j-th energy-dissipated device;
θ j ——The included angle between the energy-dissipated direction and the plane for j-th energy-dissipated device;
Δu j ——The relative horizontal displacement at the two ends of j-th energy-dissipated device. When the damping factor and effective rigidity of the energy-dissipated device are related to the structural vibration period, the value corresponding to the foundational vibration period of the 143
energy-dissipated structure may be selected. 5
The energy dissipated by displacement-related type, speed non-linear-related type and other
types of energy-dissipated devices may be estimated according to the following equation:
W cj= A j
(12.3.4-4)
Where, A j ——The area of restoring-force characteristics of the j-th energy-dissipated device at the relative horizontal displacement Δu j. The effective rigidity of energy-dissipated devices may be the secant rigidity of restoring-force characteristics of the j-th energy-dissipated device at the relative horizontal displacement Δu j. 6
When the effective damping ratio added to the structure by the energy-dissipated components
exceeds 25%, it should be counted according to 25%. 12.3.5
1
Design parameters of energy-dissipated components shall meet the following requirements: For energy-dissipated components consisted of the speed-related energy-dissipated device
with supporting components such as the diagonal, seismic wall or beam, the rigidity of the supporting components in the direction of energy-dissipated device may be calculated according to the following equation:
K b ≥（6π / T1 ）C D
(12.3.5-1)
Where, K b ——The rigidity of the supporting components in the direction of the energy-dissipated device;
C D ——The linear damping factor of the energy-dissipated device; T 1 ——The foundational natural vibration period of the energy-dissipated structure. 2
Total thickness of viscoelastic materials in viscoelastic energy-dissipated devices shall meet
the following formula:
t ≥ Δu ［ / γ ］ Where,
(12.3.5-2)
t ——The total thickness of viscoelastic materials in viscoelastic energy-dissipated devices;
Δu ——The maximum possible displacement along the direction of energy-dissipated devices; ——The maximum allowable shear strain of viscoelastic materials. ［γ ］ 3
When energy-dissipated components are composed of displacement-related energy-dissipated
devices and supporting components such as diagonal bracing, seismic wall or beam, resilience model parameter of energy-dissipated components should meet the following requirements: 144
Δu py / Δu sy ≤2/3 Where,
(12.3.5-3)
Δu py ——The yielding displacement or sliding displacement of energy-dissipated
components along horizontal direction;
Δu sy ——The inter-storey yielding displacement of structures setting energy-dissipated components. 4
The ultimate displacement of energy-dissipated devices shall not be less than 1.2 times of
maximum displacement of energy-dissipated devices under rare earthquake. The ultimate speed of speed-related energy-dissipated devices shall not be less than 1.2 times of maximum speed of energy-dissipated devices under earthquake action, and energy-dissipated devices shall meet the bearing capacity requirements under this ultimate speed. 12.3.6
1
Performance inspection of energy-dissipated devices shall meet the following requirements: As for viscous fluid energy-dissipated devices, random inspection shall be carried out by
third party, 20% of products of the same project, the same type and the same specification and no less than 2 shall be inspected, inspection qualification rate is 100, inspected energy-dissipated devices can be used in main structures. As for other type energy-dissipated devices, random inspection quantity shall be 3% of products of the same type and the same specification; when there are few products of the same type and the same specification, 3% of products of the same type and no less than 2 can be inspected, inspection qualification rate is 100%, inspected energy-dissipated devices can not be used in main structures. 2
As for speed-related energy-dissipated devices, under the design displacement and design
speed amplitude, recirculating 30 cycles in structural fundamental frequency, their main design index error and decrement shall not exceed 15%.As for displacement-related energy-dissipated devices, under the design displacement amplitude, recirculating 30 cycles, their main design index error and decrement shall not exceed 15% and they shall be free from obvious low cycle fatigue phenomenon. 12.3.7
When the structure adopts energy-dissipated design, relevant positions of energy-dissipated
components shall meet the following requirements: 1
Connection between energy-dissipated devices and supporting components shall meet the
detailing requirements of this code and relevant regulations to relevant component connection. 2
Under the action of the maximum damping force applied on main structures by
energy-dissipated devices, the connecting components between energy-dissipated devices and main structures shall operate at the elastic range. 3
In the design of structural components connected with energy-dissipated components,
additional internal force transferred by energy-dissipated components shall be taken into consideration. 12.3.8
When the seismic performance of energy-dissipated structure is improved obviously, seismic
detailing requirements of main structures can be reduced properly. The reducing degree can be determined by ratio of seismic influence coefficient of energy-dissipated structure to seismic influence coefficient of structures not equipped with energy-dissipated devices; the maximum reducing degree 145
shall be controlled within 1 degree.
13
Nonstructural Components 13.1
13.1.1
General
The requirements of this Chapter shall mainly be applied to the connection of nonstructural
components with the building structure. The nonstructural components include permanent building nonstructural components as well as mechanical and electrical equipments that are attached to building structures. Notes: 1
Building nonstructural components ref er to the fixing components and parts except the load-bearing skeleton system,
mainly including non-bearing seismic wall, components attached to the floor and roof, decorative components and parts, and large-sized storage racks fixed on the floor etc.. 2
The attached mechanical and electrical equipments refer to the mechanical and electrical components, parts and systems
serving the functions of modern buildings, mainly include elevators, lighting, emergency power, communication facility, pipeline, heating and air-conditioning system, smoke and fire monitoring and protection system, and community antenna.
13.1.2
Nonstructural components shall adopt different seismic measures to reach corresponding
performance-based design objectives according to the precautionary categories of corresponding buildings, the results of nonstructural earthquake damage as well as their influence scope to the whole building structure. Some methods for building nonstructural components and building auxiliary mechanical and electrical equipments to realize performance-based seismic design objectives can be carried out according to Section M.2 in Appendix M of this code. 13.1.3
When two nonstructural components, with different seismic requirements, are connected with
one another, the seismic design shall be carried out according to the higher requirements. When the connection of one nonstructural component is damaged, this damage shall not cause the failure of other adjacent nonstructural components with higher requirements. 13.2 13.2.1
Essentials in Calculation
When seismic calculation is carried out for building structures, the influence of nonstructural
components shall be taken into consideration according to the following requirements: 1
The gravity of building components and the attached mechanical and electrical equipments
shall be taken into consideration for calculating the earthquake action. 2
As for the flexibly-connected building components, the rigidity may not be taken into
consideration; as for the rigid nonstructural components embedded in the lateral-force-resisting component plane, the rigidity influence shall be taken into consideration by adopting simplified methods such as the period adjustment. In generally, the seismic bearing capacity shall not be taken into consideration; when there are specific details of seismic design, the seismic bearing capacity may be taken into consideration according to relevant provisions. 3
The structural components supporting nonstructural components shall take the earthquake
action effect of nonstructural components as additional action, and shall meet the anchoring requirements of connecting pieces. 146
13.2.2
The calculating method of earthquake action for the nonstructural components shall meet the
following requirements: 1
The seismic force of all components and parts shall be applied at their centers of gravity, and
the horizontal seismic force shall be applied in any horizontal direction. 2
In generally, the earthquake action produced by nonstructural components themselves may
adopt the equivalent lateral-force method for calculation. As for the nonstructural components supporting in different storeys or at both sides of seismic joints, except the earthquake action produced by the deadweight, the effect of the relative displacement appeared between all supporting points shall be taken into consideration at the same time. 3
When the architectural natural vibration periods of attached facilities (including support) are
larger than 0.1s and their gravities exceed 1% of those of their storeys, or the gravities of attached facilities exceed 10% of those of their storeys, seismic design of integral structure model should be adopted, or floor spectrum method specified in Section M.3 in Appendix M of this code can be adopted for calculation. As for the equipments therein inelastically connected with the roof, the equipments and roofs can be directly regarded as a mass point and counted in the analysis of the whole structure to obtain the earthquake action beared by the equipments. 13.2.3
When equivalent lateral-force method is adopted, the standard value of the horizontal
earthquake action should be calculated according to the following formula:
F = γηζ 1ζ 2α maxG
(13.2.3)
Where, F ——The horizontal earthquake action standard value applied at the center of gravity of the nonstructural components along the most unfavorable direction;
γ ——The functional factor of the nonstructural component, it is determined according to relevant standards or implemented according to M.2 in Appendix M of this code;
η ——The type factor of nonstructural component, it is determined according to relevant standards or implemented according to M.2 in Appendix M of this code;
ζ 1 ——The factor of state, in cases such as precast components, cantilever components, any equipment and flexible system whose strong point is lower than center of mass, the factor should be taken as 2.0; and in other cases may be taken as 1.0;
ζ 2 ——The factor of location; for the top of structures, the factor should be taken as 2.0; for the bottom, the factor should be taken as 1.0; and is in linear distribution along the height of structures; for the structures that need adopt the time history analysis method to carry out calculation according to the requirements in Chapter 5 of this code, such factor shall be adjusted according to the results of calculation;
α max ——The maximum value of seismic influence coefficient, that may be adopted in accordance with the requirements for frequent earthquakes specified in Article 5.1.4 of this code;
G ——The gravity of nonstructural components, it shall include the gravity of relevant 147
personnel, media in the vessels and pipes during operations, as well as the gravity of materials in the storage cabinet. 13.2.4
The internal force, which produced by the relative horizontal displacement among the
supporting points of the nonstructural components, shall be calculated. That may be determined by using the product of the rigidity of the component in the displacement direction and the relative horizontal displacement among the specified supporting points. The rigidity of the nonstructural component in the displacement direction shall adopt respectively simplified mechanical models such as rigid connection, hinged connection, elastic connection or sliding connection according to the actual connection state at its end. The relative horizontal displacement between the adjacent storeys may be adopted according to the limit values specified in this code. 13.2.5
The fundamental combination between the earthquake action effects (including effects
caused by dead-weight and relative displacement of support) of nonstructural components and other load effects shall be calculated according to the relevant requirements of structural components in this code. As for the curtain seismic wall, the combination of earthquake action effect and wind load effect shall be calculated; as for vessels, action effects caused by temperature and operating pressure during equipment operation shall be taken into consideration. During seismic checking of nonstructural components, frictional force must not be used as the resistibility that resisting earthquake action; bearing capacity seismic adjustment coefficient may adopt 1.0. 13.3 13.3.1
Essential Measures for Architectural Members
In building structures, locations for installing the embedded and anchoring parts that connect
the architectural members such as curtain seismic wall, enclosure seismic wall, partition seismic wall, parapet, awning, trademark, billboard, ceiling and large-sized storage rack, the strengthening measures shall be adopted to bear the earthquake action transferred by the architectural members. 13.3.2
The materials, types and arrangement of nonbearing seismic wall shall be determined through
comprehensive analysis according to the factors such as Intensity, building height, building shape, structural inter-storey deformation and seismic wall itself lateral-force-resisting performance, as well as shall meet the following requirements: 1
Light-weight seismic wall materials should be first considered for nonbearing seismic wall.
When masonry seismic wall is adopted, measures shall be taken to reduce the adverse effect to the main structure, besides tie bar, horizontal tie beam, ring beam and constructional column shall be installed to reliably tie with main structures. 2
The rigid nonbearing seismic wall shall be arranged to avoid mutation in rigidity and
Intensity distribution. When the enclosure seismic wall is arranged asmmetrically and evenly, the adverse effects of the difference between quality and rigidity to the seismic action of main structure shall be taken into consideration. 3
The seismic wall shall be reliably tied with the main structures, shall be able to adapt storey
drift along different directions of the main structures, shall be possessed of deformability meeting inter-storey deflection for Intensity 8 and 9, as well as shall be possessed of vertical deformability caused by meeting joint rotation when connected with cantilever components. 148
4
The connecting pieces of external seismic wall boards shall be possessed of sufficient
ductility and proper turning power, should meet the requirements of main structure inter-storey deformation under the precautionary earthquake. 5
The masonry parapet shall be anchored with the main structure at the pedestrian flow
gateway and passage. For Intensity 6~8, the height of non-anchored parapet not in the gateway should not exceed 0.5m; for Intensity 9, the parapet shall be provided with anchorage. Sufficient width shall be left for the parapets at the seismic joints; and free ends at both sides of the joint shall be strengthened. In the multi-story masonry structure, architectural members such as nonbearing seismic wall
13.3.3
shall meet the following requirements: 1
Post-laid nonbearing partition seismic wall shall be equipped with 2φ6 tie reinforcements to
tie with bearing seismic wall or columns every other 500mm~600mm along the seismic wall height, and each side shall stretch into the seismic wall no less than 500mm. For Intensity 8 and 9, as for the post-laid partition seismic wall whose lengths are larger than 5m, the top of the seismic wall shall be tied with floor slab or beam, and reinforced concrete constructional columns should be installed at the ends of independent seismic wall legs and beside the portals. 2
Flues, air ducts and refuse chutes shall not weaken seismic wall. When seismic wall are
weakened, strengthening measures shall be adopted for seismic wall. Chimney shafts attached to seismic wall without vertical reinforcements or chimneys protruding out of the roofs should not be adopted. 3 13.3.4
Reinforced concrete prefabricated corbel table without anchorage shall not be adopted. Masonry filler seismic wall in the reinforced concrete structure shall also meet the following
requirements: 1
The plane and vertical arrangement of filler seismic wall should be even and symmetrical as
well as avoid weak layer or short column. 2
Masonry mortar strength Grade shall not be less than M5; solid block strength Grade should
not be less than MU2.5; hollow block strength Grade should not be less than MU3.5. The top of the seismic wall shall be closely connected with the frame beam. 3
Filler seismic wall shall be equipped with 2φ6 tie bars every other 500mm~600mm along the
total height of frame columns. The length of tie bars stretching into seismic wall: for Intensity 6 and 7, full length along seismic wall; for Intensity 8 and 9, full length. 4
When seismic wall are longer than 5m, the top of seismic wall should be tied with beams.
When the length of seismic wall exceeds 8m or twice of the storey height, reinforced concrete constructional columns should be installed. When the height of seismic wall exceeds 4m, on the half height of the seismic wall should be installed full-length reinforced concrete horizontal tie beams that are connected with columns. 5
Filler seismic wall between the staircase and pedestrian flow passage shall be strengthened
with steel mesh mortar surface course. 13.3.5
The enclosure seismic wall and partition seismic wall of single-story factory buildings with
reinforced concrete columns shall also meet the following requirements: 149
1
The enclosure seismic wall of factory buildings should adopt lightweight seismic wallboards
or reinforced concrete large-sized seismic wallboards. The masonry enclosure seismic wall shall adopt external-bond type and reliable tie with columns. When the outside column space is 12m, lightweight seismic wallboards or reinforced concrete large-sized seismic wallboards shall be adopted. 2
Rigid enclosure seismic wall should be arranged evenly and symmetrically along longitudinal
direction. External-bond type on one side, and embedded-laying type or open type on the other side should not be adopted, neither should masonry seismic wall on one side and lightweight seismic wallboard on the other side. 3
The high-span protection seismic wall of unequal-height factory buildings and curtain
seismic wall at the joints of transverse and longitudinal factory buildings should adopt lightweight seismic wallboards. For Intensity 6 and 7, masonry shall not be built directly on the low-span roof. 4
Masonry enclosure seismic wall shall be equipped with cast-in-situ reinforced concrete ring
beams in the following positions: 1)
One row shall be installed on trapezoidal roof truss end top chord and column top
elevation respectively; rows can be combined when the roof truss end height is no larger than 900mm; 2)
One row of ring beam shall be set on the window top every other 4m according to the
principle of upper-dense and lower-sparse. As for the high-low-span protection seismic wall of unequal-height factory buildings and curtain seismic wall at the span joints of longitudinal seismic wall, vertical spaces of ring beams shall not be larger than 3m; 3)
Reinforced concrete beams shall be set for gables along the roof and shall be connected
with ring beams on the roof truss end top chord elevations. 5
The structure of ring beams shall meet the following requirements: 1)
The ring beams should be closed. The sectional width of ring beams should be identical
with seismic wall thickness. Sectional height shall not be less than 180mm. The longitudinal bars of ring beams: no less than 4φ12 for Intensity 6~8; no less than 4 φ14 for Intensity 9; 2)
The longitudinal bar of column top ring beam at the corner of factory building within
the range of end bay: no less than 4 φ14 for Intensity 6~8; no less than 4 φ16 for Intensity 9.The diameter of hoops within the range of 1m at both sides of the corner should not be less than φ8, and the space should not be larger than 100mm. No less than 3 horizontal diagonal bars whose diameters are the same as longitudinal bar shall be installed at the corner of ring beam; 3)
The ring beams shall be firmly connected with columns or roof trusses. The gable
beams shall be tied with roof boards. Anchorage reinforcement for connecting top ring beam and column or roof truss should not be less than 4 φ 12 and anchorage length should not be less than 35 times of reinforcement diameter. Ties between ring beam and column or roof truss at the seismic joint should be strengthened. 6
Seismic wall beam should adopt cast-in-situ type. When prefabricated seismic wall beams are
adopted, the beam bottom shall be firmly tied with brick seismic wall top surface and anchored with columns. Adjacent seismic wall beams at the corner of factory buildings shall be reliably connected with each other. 7
Masonry partition seismic wall should be separated with or flexibly connected with columns, 150
and measures shall be adopted to make seismic wall stable. Cast-in-situ reinforced concrete capping beams shall be installed on the top of partition seismic wall. 8
As for the foundation of brick seismic wall, for Intensity 8 with Site-category III and IV site
and Intensity 9, prefabricated foundation beams shall adopt cast-in-situ joints. When strip foundation is set, continuous cast-in-situ reinforced concrete ring beams shall be installed on the column foundation top elevation, and reinforcements shall not be less than 4 φ 12. 9
Height of masonry parapet should not be larger than 1m and measures shall be adopted to
prevent overturning during earthquake. 13.3.6
1
Enclosure seismic wall of steel factory buildings shall meet the following requirements: Lightweight plates shall be first considered for the enclosure seismic wall of factory buildings.
Precast reinforced concrete seismic wallboards should be flexibly connected with columns. For Intensity 9, lightweight plates shall be adopted. 2
The masonry enclosure seismic wall of single-story factory buildings shall be built close to
and tied with columns, and measures shall also be adopted to make seismic wall not obstruct vertical horizontal displacement of factory building colonnade. For Intensity 8 and 9, embedded-laying shall not be adopted. 13.3.7
The connecting pieces between components of various ceilings and the floor shall be able to
undertake the deadweight of the ceiling, the suspending heavy objects, and the relevant mechanic and electrical equipments, as well as the additional earthquake action. The bearing capacity of anchorage shall be larger than that of the connecting pieces. 13.3.8
Cantilever awnings or awnings with one end supported by the column shall be reliably
connected with the main structure. 13.3.9
The details of seismic design for the glass curtain seismic wall, precast seismic wallboards,
the cantilever components attached to the roofs, as well as large-sized storage rack shall meet the requirements of relevant special standards. 13.4 13.4.1
Essential Measures for Supports of Mechanical and Electrical Components
The seismic measures of connection components and parts of attached elevator, illumination
& emergency power supply system, smoke & fire monitoring and fire fighting system, heating and air conditioning system, communication system, as well as common antenna with building structure shall be determined through comprehensive analysis according to precautionary Intensity, building usage function, building height, structural type, deformation characteristics, locations of attached facilities as well as operating requirements. 13.4.2
Seismic precautionary requirements may not be considered for the supports of the following
attached mechanical and electrical equipments: 1
The equipment that has gravity not exceeding 1.8kN;
2
The gas pipe that has less than 25 mm inner diameter, and electrical piping that has less than
60mm inner diameter; 3
2 The air pipe that has a rectangular sectional area less than 0.38m and has less than 0.70m
round diameter; 151
4 13.4.3
Boom suspending pipeline whose boom calculation length is no larger than 300mm. The attached mechanical and electrical equipments shall not be installed in locations that may
cause secondary damages such as operation failure. For equipments with seismically-isolated devices, it shall be paid attention to the influence of strong vibration to the connecting pieces, and resonance of equipments with the building structure shall also be avoided. The supports of attached mechanical and electrical equipments shall have sufficient rigidity and strength, shall have reliable connection and anchoring with the building structure, as well as shall be able to restore operation rapidly after the precautionary earthquake occurrence. 13.4.4
The openings for pipelines, cables, air-pipes, and equipment shall try to reduce the
weakening caused to the main load-bearing structural components; strengthened measures shall be taken for perimeter of the openings. The connections of pipelines and equipments with the building structures shall be able to allow a certain relative deflection between them. 13.4.5
The supports or the connecting pieces of the attached mechanical and electrical equipments
shall be able to transfer all the earthquake action of the equipments to the building structures. In building structures, as for the locations for installing the embedded and anchoring parts of the attached mechanical and electrical equipments, the strengthened measures shall be taken to resist the earthquake action transferred by the attached mechanical and electrical components. 13.4.6
The water tank, which located at the higher position of the building, shall be connected with
the structural components reliably. The additional earthquake action effect caused by water tank and water to the structures shall be also taken into consideration. 13.4.7
As for the attached equipments, which need operate continuously under the precautionary
earthquake, should be installed at locations of the building structure where the seismic response is smaller, corresponding strengthened measures shall be adopted for the structural components in relevant positions.
14
Subterranean Buildings 14.1
14.1.1
General
This chapter is mainly applicable to independent subterranean buildings such as underground
garage, underpass, underground substation and underground space complex, excluding subway and urban highway tunnel, etc. 14.1.2
Subterranean buildings should be constructed on solid, even and stable subsoil. When the
subterranean buildings are located in unfavorable sections such as soft soil, liquefied soil or fault fracture zone, corresponding measures shall be adopted with regard to their influence to structural seismic stability. 14.1.3
The structural arrangement sress of subterranean buildings shall strive to be simple,
symmetrical, regular and smooth. The shape and structure of cross s ection should not mutate along the longitudinal direction. 152
14.1.4
The structural system of subterranean buildings shall be determined according to operating
requirements, site engineering geological conditions and construction methods; it shall have favorable integrity and avoid the lateral rigidity and bearing capacity mutation of lateral-force-resisting structures. Seismic Grades of Category C reinforced concrete underground structures: no less than 4 Grade for Intensity 6 and 7; no less than 3 Grade for Intensity 8 and 9. Seismic Grades of Category B reinforced concrete underground structures: no less than 3 Grade for Intensity 6 and 7; no less than 2 Grade for Intensity 8 and 9. 14.1.5
As for the subterranean buildings in the rocks, their side slopes on both sides of gateway and
the entrance slopes shall adopt reasonable portal structure types according to the topographic and geologic conditions to improve their seismic stability. 14.2 14.2.1
Essentials in Calculation
As for the following subterranean buildings adopting seismic measures according to the
requirements of this chapter, earthquake action calculation can be omitted: 1
For Intensity 7 with Site-category I and II, Category C subterranean buildings.
2
For Intensity 8 (0.20g) with Site-category I and II, medium-small span Category C
subterranean buildings no larger than 2 stories with regular shape. 14.2.2
Seismic calculation models of subterranean buildings shall be determined according to the
structural actual situation and meet the following requirements: 1
They shall be able to accurately reflect the actual force conditions of surrounding retaining
structures and internal components. Internal structures separated with surrounding retaining structures can adopt the same calculation model as above-ground buildings. 2
As for subterranean buildings longer in longitudinal direction with even and regular
surrounding stratigraphic distribution and symmetry axis, plane strain analysis mode can be adopted for structural analysis as well as calculation methods such as reaction displacement method, equivalent horizontal seismic acceleration method and equivalent lateral force method can be adopted. 3
As for the subterranean buildings whose length-width ratio and height-width ratio are less
than 3 and other than those in Item 2 of this Article should adopt space structure analysis calculation model and soil layer-structure time history analysis calculation method. 14.2.3
Seismic calculation design parameters of subterranean buildings shall meet the following
requirements: 1
They shall meet the following requirements along the direction of earthquake action : 1)
As for underground structures analyzed according to plane strain model, only transverse
horizontal earthquake action may be calculated; 2)
As for irregular underground structures, structural transverse and longitudinal horizontal
earthquake actions should be calculated at the same time; 3)
As for complex underground structures such as underground space complex, vertical
earthquake action should be taken into consideration for Intensity 8 and 9. 153
2
The values of earthquake action shall be reduced correspondingly along the underground
depth: earthquake action in the rock bed can adopt half of that on the ground, earthquake action at different depth from the ground to the bed rock can be determined according to interpolation method; when the ground surface, soil layer interface and bedrock surface are relatively even, one-dimensional fluctuation method can be adopted; when soil layer interface, bedrock surface or ground surface fluctuates obviously, two-dimensional or three-dimensional finite element method should be adopted. 3
Structural gravity load representative value shall adopt the value of the standard value of
structural & component deadweight and water & soil pressure adding the combination value of each variable load. 4
When the soil layer-structure time history analysis method or equivalent horizontal seismic
acceleration method is adopted, the dynamic characteristic parameters of soil and rock can be determined by test. 14.2.4
The seismic checking of subterranean buildings shall not only meet the requirements of
Chapter 5 in this code but also the following requirements: 1
Seismic checking for sectional bearing capacity and component deformation under frequent
earthquake action shall be carried out. 2
As for irregular subterranean buildings, underground substation and underground space
complex, seismic deformation checking calculation under rare earthquake action shall be carried out. The simplified method specified in Section 5.5 of this code can be adopted for calculation. Elastoplastic storey drift angle limit [θ p] of concrete structure should adopt 1/250. 3
As for the subterranean buildings in the liquefied subsoil, the anti-floating stability during
liquefaction shall be checked. As for the frictional resistance of the liquefied soil layer to the underground diaphragm seismic wall and uplift pile, its liquefied reduction coefficient should be determined according to the ratio of measured standard penetration blow count to critical standard penetration blow count. 14.3 14.3.1
Details and Anti-Liquefaction Measures
The seismic structures of reinforced concrete subterranean buildings shall meet the following
requirements: 1
Cast-in-situ structure should be adopted. If some prefabricated components shall be installed,
they shall reliably connected with their surrounding components. 2
The minimum size of underground reinforced concrete frame structure components shall not
be less than the requirements of the same ground surface structure components. 3
The minimum total reinforcement ratio of the longitudinal reinforcement in center column
shall increase by 0.2%.The hoops at the joint of center column and the beam, top plate, middle floor slab or soleplate shall be denser, and their scope and structure shall be the same as the columns of ground frame structure. 14.3.2
The top plate, soleplate and floor slab of subterranean buildings shall meet the following
requirements: 1
Beam and slab structures should be adopted. When the slab-column-anti-seismic seismic wall
is adopted, structural concealed beams shall be set in the slab and strip on the column. The detailing 154
requirements shall be the same as the s ame ground structure components. 2
As for the composite seismic wall, top plate, soleplate and floor slab of the underground
diaphragm seismic wall, at least 50% negative moment reinforcements shall be anchored into the underground diaphragm seismic wall, and anchorage length shall be determined according to the force calculation; positive moment reinforcement shall be anchored into the inner lining, and no less than the specified anchorage length. 3
When the floor slab is equipped with openings, the opening width shall not be larger than
30% of the width of the floor slab in this storey; the opening should be arranged to make the distribution of structural quality and rigidity even and symmetrical and avoid mutation. Boundary beams or concealed beams meeting the detailing requirements shall be arranged around the openings. When liquefied soil layer exists in the soil mass and subsoil around the subterranean
14.3.3
buildings, the following measures shall be adopted: 1
Measures eliminating or relieving liquefied influence such as grouting reinforcement and soil
replacement shall be adopted for the liquefied soil layer. 2
In checking the liquefied floating of underground structure, if necessary, corresponding
anti-floating measures such as setting of uplift piles and configuration of weights shall be adopted. 3
When liquefied soil thin interlayer exists, or underground diaphragm seismic wall enclosure
structure whose depth is larger than 20m encounters the liquefaction soil layer during construction, subsoil anti-liquefaction treatment can be omitted, but the influence of soil pressure increase and frictional resistance decrease caused by soil layer liquefaction shall be taken into consideration for the checking calculation of its bearing capacity and anti-floating stabili ty. When the subterranean buildings pass through the ancient stream channel whose bank slope
14.3.4
may slide during earthquake or soft soil zone where obvious uneven settlement may occur, measures such as replacement of soft soil or arrangement of pile foundation shall be adopted. As for the subterranean buildings in the rock, the following seismic measures shall be
14.3.5
adopted: 1
When the gateway and fault fracture zone section untreated by grouting reinforcement adopt
composite support structures, the inner lining structure shall adopt reinforced concrete lining and must not adopt plain concrete lining. 2
When separated lining is adopted, the inner lining structure shall be equipped with horizontal
brace at the joint of arch seismic wall to resist the seismic wall rock. 3
When drilling and blasting method is adopted during construction, compact backfill shall be
carried out between the preliminary support and seismic wall rock stratum. In the process of dry masonry block stone backfill, grouting reinforcement shall be adopted.
155
Appendix A
The Earthquake Intensity, Basic Accelerations of Ground
Motion and Design Earthquake Groups of Main Cities in China This appendix provides the precautionary Intensity, the design basic accelerations of ground motion and the design earthquake groups used in the seismic design of building construction situated at the central region of cities and towns that assigned to county level and above in the seismic precautionary zones of China. Note: In this appendix, “the design earthquake group 1, 2 and 3” is referred as “group 1, group 2 and group 3”.
A.0.1
1
The capital city and municipalities directly under the central government The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 1: Beijing (Dongcheng, Xicheng, Chongwen, Xuanwu, Chaoyang, Fengtai, Shijingshang, Haidian, Fangshan, Tongzhou, Shunyi, Daxing, Pinggu), Yanqing, Tianjin (Hangu) and Ninghe. 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 2: Beijing (Changping, Mentougou, Huairou), Miyun; Tianjin (Heping, Hedong, Hexi, Nankai, Hebei, Hongqiao, Tanggu, Dongli, Xiqing, Jinnan, Bechen, Wuqing, Baodi), Jixian and Jinghai 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Shanghai (Huangpu, Luwan, Xuhui, Changning, Jing’an, Putuo, Zhabei, Hongkou, Yangpu, Minhang, Baoshan, Jiading, Pudong, Songjiang, Qingpu, N anhui, Fengxian). Group 2: Tianjin (Dagang) 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Group 1: Shanghai (Jinshan), Chongming; Chongqing (Yuzhong, Dadukou, Jiangbei, Shapingba, Jiulongpo, Nan’an, Beibei, Wansheng, Shuangqiao, Yubei, Ba’nan, Wanzhou, Fuling, Qianjiang, Changshou, Jiangjin, Hechuan, Yongchuan, Nanchuan), Wushan, Fengjie, Yunyang, Zhongxian, Fengdu, Bishan, Tongliang, Dazu, Rongchang, Qijiang, Qianjiang, Shizhu and Wuxi *. Note: The superscript* means that the center of the city situates on the dividing line of such precautionary zone and lower precautionary zone, similarly hereinafter.
A.0.2
1
Hebei Province The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 1: Tangshan (Lubei, Lunan, Guye, Kaiping, Fengrun, Fe ngnan), Sanhe, Dachang, Xianghe, Huailai and Zhuolu. Group 2: Langfang (Guangyang, Anci) 156
2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group l: Handan (Congtai, Hanshan, Fuxing, Fengfeng Mining Area), Renqiu, Hejian, Dacheng, Luanxuian, Weixian, Cixian, Xuanhua County, Zhangjiakou (Xiahuayuan, Xuanhua Area) and Ningjin*. Group 2: Zhuozhou, Gaobeidian, Laishui, Gu’an, Yongqing, Wenan, Yutian, Qian’an, Lulong, Luannan, Tanghai, Leting, Yangyuan, Handan County, Daming, Linzhang and Cheng’an. 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Zhangjiakou (Qiaodong, Qiaoxi), Wanquan, Huai’an, Anping, Raoyang, Jinzhou, Shenzhou, Xinji, Zhaoxian, Longyao, Renxian, Nanhe, Xinhe, Suning and Baixiang. Group 2: Shijiazhuang (Chang’an, Qiaodong, Qiaoxi, Xinhua, Yuhua, Jingxing Mining Area), Baoding (Xinshi, Beishi, Nanshi),Cangzhou (Yunhe, Xinhua), Xingtai(Qiaodong, Qiaoxi),Hengshui, Bazhou, Xiongxian, Baxian, Yixian, Cangxian, Zhangbei, Xinglong, Qianxi, Funing, Changli, Qingxian, Xianxian, Guangzong, Pingxiang, Jize, Quzhou, Feixiang, Guantao, Guangping, Gaoyi , Neiqiu, Xingtai County, Wu’an, Shexian, Chicheng, Dingxing, Rongcheng, Xushui, Anxin, Gaoyang, Boye, Lixian, Shenze, Weixian, Gaocheng, Luancheng, Wuqiang, Yizhou, Julu. Shahe, Lincheng, Botou, Yongnian, Chongli and Nangong* Group
3:
Qinhuangdao
(Haigang,
Beidaihe),
Qingyuan,
Zunhua,
Anguo,
Laiyuan,
Chengde(Yingshouyingzi*). 4 The place-names assigned to Intensity 6 with the design basic acceleration of ground motion equal to 0.05g: Group 1: Weichang and Guyuan. Group 2: Zhengding, Shangyi, Wuji, Pingshan, Luquan, Jingjing County, Yuanshi, Nanpi, Wuqiao, Jingxian and Dongguang. Group 3: Chengde (Shuangqiao, Shuangluan), Qinhuangdao(Shanhaiguan), Chengde county, Longhua, Kuancheng, Qinglong, Fuping, Mancheng, Shunping, Tangxian, Wangdu, Quyang, Dingzhou, Xingtang, Zanhuang, Huangye, Haixing, Mengcun, Yanshan, Fucheng, Gucheng, Qinghe, Xinle, Wuyi, Zaoqiang ,Weixian, Fengning, Luanping, Pingquan, Linxi, Lingshou a nd Qiu xian. A.0.3
Shanxi Province
1 The place-names assigned to Intensity 8 with the design basic acceleration of ground motion equal to 0.20g: Group l: Taiyuan (Xinghualing, Xiaodian, Yingze, Jiancaoping, Wanbailin, Jinyuan), Jinzhong, Qingxu, Yangqu, Xizhou, Dingxiang, Yuanping, Jiexiu, Lingshi, Fenxi, Daixian, Huozhou, Guxian, Hongdong, Linfen, Xiangfen, Fushan and Yongji. Group 2: Qixian, Pingyao, Taigu 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: 157
Group 1: Datong (City (City Area, Mining Area, Southern Southern Suburb), Suburb), Datong County, County, Huairen,
Fanshi,
Wutai, Guangling, Lingqiu, Ruicheng and Yicheng. Group 2: Shuozhou (Suochengqu), Hunyuan, Shanyin, Gujiao, Jiaocheng, Wenshui, Fenyang, Xiaoyi, Quwo, Houma, Xinjiang, Jishan, Jiangxian, Hejin, Wanrong, Wenxi, Linyi, Xiaxian, Yuncheng, Pinglu, Qinquan * and Ningwu.* 3
The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.10g: Group 1: Yanggao and Tianzhen. Group 2: Datong (Xinrong), Changzhi (City Area, Suburb), Yangquan (City Area, Mining Area, Suburb), Changzhi County, Zuoyun, Youyu, Youyu, Shenchi, Shouyang, Xiyang, Anze, Pingding, Pi ngding, Xiangning, Yuanqu, Licheng, Lucheng and Huguan. H uguan. Group 3: Pingshun, Yushe, Wuxiang, Loufan, Jiaokou, Xixian, Puxian, Jixian, Jingle, Mengxian, Qinxian and Shuozhou (Pinglu) 4
The place-names place-names assigned to Intensity 6 with the design basic acceleration of of ground motion
equal to 0.05g: Group 3: Pianguan, Hequ, Baode, Xingxian, Linxian, Fangshan , Liulin,Wuzhai, Kelan, Lan xian, Zhongyang, Shilou, Yonghe, Daning, Jincheng, Luliang, Zuoquan, Xiangyuan, Tunliu, Changzi, Gaoping, Yangcheng Yangcheng and Zezhou. A.0.4
1
Inner-Mongolia Autonomous Region The place-names assigned to Intensity 8 with the design basic acceleration of ground motion motion
equal to 0.30g: Group 1: Tumoteyouqi, Dalad Banner*. 2
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion motion
equal to 0.20g: Group 1: Huhhot (Xincheng, Huimin, Yuquan, Yuquan, Saihan), Baotou (Kunducang, Donghe, Qingshan, Jiuyuan), Wuhai (Haibowan, Hainan, Wuda), Tumotezuoqi, Hangmianhouqi, Dengkou and Ningcheng. Group 2: Baotou (Shiguai), Toqtoh Toqtoh * 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 1: Chifeng (Hongshan * and Yuanbaoshan District), Harqin Barnner, Bayanzhuoer, Wuyuan, Urad Front Banner and Liangcheng. Group 2: Guyang, Wuchuan and Helingeer Group 3: Alxa Left Banner 4 The place-names assigned to Intensity 7 with the design basic acceleration of ground motion equal to 0.10g: Group 1: Chifeng (Songshan District), Chayouqianqi, Kailu, Aohanqi, Zhalantun, Tongliao*. Tongliao*. 158
Group 2: Qingshuihe, Ulan Qab, Zhuozi, Fengzhen, Wutelahouiqi and Wutelazhongqi Wutelazhongqi Group 3: Erdos and Zhungeerqi 5
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion motion
equal to 0.05g: Group 1: Manzhouli, Xinbaerhuyouqi, Molidawaqi, Arun Banner, Jalaid Banner, Ongniod Banner, Shangdu, Uxin Banner, Kezuozhongqi, Kezuohouqi, Naimanqi, Kulunqi and Sonin Right Banner. Group 2: Xinghe, Chayouhouqi, Group 3: Da’erhanmaoming’anlianheqi, Alax Right Banner, Otog Banner, Otog Front Banner, Baotou(Baiyun Mining Area), Ejin Horo Banner, Hangjinqi, Siwangziqi and Chayouzhongqi A.0.5
1
Liaoning Province The place-names assigned to Intensity 8 with the design basic acceleration of ground motion motion
equal to 0.20g: Group 1: Pulandian and Donggang 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion motion
equal to 0.15g: Group 1: Yingkou (Zhanqian, Xishi, Bayuquan, Laobian), Dandong (Zhenxing, Yuanbao, Zhen’an), Haicheng, Dashiqiao, Wafangdian, Gaizhou and Dalian (Jinzhou) 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion motion
equal to 0.10g: Group 1: Shenyang (Shenhe, Heping, Dadong, Huanggu, Tiexi, Sujiatun, Dangling, Shenbei, Yuhong), Anshan (Tiedong, Tiexi, Lishan, Qianshan), Chaoyang (Shuangta, Longcheng), Liaoyang(Baita, Wenshng, Hongwei, Zhanggongling, Taizihe), Fushun (Xinfu, Dongzhou, Wanghua), Wanghua), Tieling (Yinzhou, Qinghe), Panjin (Xinglongtai, Shuangtaizi), Panshan, Chaoyang County, Liaoyang County, County, Tieling County, Beipiao, Jianping, Kaiyuan, Fushun County*, Dengta, Tai’an, Liaozhong and Dawa. Group 2: Dalian (Xigang, Zhongshan, Shahekou, Ganjingzi, Lushun), Xiuyan and Lingyuan 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion motion
equal to 0.05g: Group 1: Benxi (Pingshan, Xihu, Mingshan, Nanfen), Fuxin (Xihe, Haizhou, Xinqiu, Taiping, Qinghemen), Huludao (Longgang, Lianshan), Changtu, Xifeng, Faku, Zhangwu, D iaobingshan, Fuxin County, Kangping, Xinmin, Heishan, Beining, Yixian, Kuandian, Zhuanghe, Changhai and Fushun (Shuncheng). Group 2: Jinzhou (Taihe, Guta, Linghe), Linghai, Fengcheng, Kelaqqinzuoyi Group 3: Xingcheng, Suizhong, Jianchang, Huludao (Nanpiao) A.0.6
1
Jilin Province The place-names assigned to Intensity 8 with the design basic acceleration of ground motion motion 159
equal to 0.20g: Qianguoerluosi, Songyuan 2
The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.15g: Da’an* 3
The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.10g: Changchun (Nanguan, Chaoyang, Kuangcheng, Erdao, Luyuan, Shuangyang), Jilin (Chuanying, Longtan, Changyi, Fengman), Baicheng, Qian’an, Shulan, Jiutai and Yongji* Yongji* 4
The place-names place-names assigned to Intensity 6 with the design basic acceleration of of ground motion
equal to 0.05g: Siping (Tiexi, Tiedong), Liaoyuan (longshan, xi’an), Zhenlai, Taonan, Yanji, Yanji, Wangqing, Tumen, Huichun, Longjing, Helong, Antu, Jiaohe, Huadian, Lishu, Panshi, Dongfeng, Huinan, Meihekou, Dongliao, Yushu, Jingyu, Fusong, Changling, Dehui, Nong’an, Yitong, Gongzhuling, Fuyu and Tongyu*. Note: The design design seismic group group of all cities cities of the county county level and and above in all over the provinces provinces belong to Group Group 1.
A.0.7
1
HeilongJiang Province The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.10g: Suihua, Luobei and Tailai 2
The place-names place-names assigned to Intensity 6 with the design basic acceleration of of ground motion
equal to 0.05g: Harbin (Songbei, Daoli, Nangang, Daowai, Xiangfang, Pingfang, Hulan, Acheng, ), Tsitshar (Jianhua, Longsha, Tiefeng, Ang’angxi, Fulaerji, Nianzishan,Meilisi), Daqing (Saertu, Longfeng, Ranghulu, Datong, Honggang), Hegang (Xiangyang, Xingshan, Gongnong, Nanshan, Xing’an, Dongshan), Mutankiang (Dong’an, Aimin, Yangming, Xi’an), Jixi (Jiguan, Hengshan, Didao, Lishu, Chengzihe, Mashan), Kiamusze(Qianjin, Xiangyang, Dongfeng, Suburb), Qitaihe (Taoshan, Xinxing, Qiezihe), Yichun (Yichun District, Wuma, Youhao), Jidong, Wangkui, Muling, Suifenhe, Dongning, Ning’an, Wudalianchi, Wudalianchi, Jiayin, Tangyuan, Tangyuan, Hua’nan, Huachuan, Yilan, Yilan, Boli, Tonghe, Tonghe, Fangzheng, Mulan, Bayan, Yanshou, Shangzhi, Binxian, Anda, Mingshui, Suiling, Qing’an, Lanxi, Zhaodong, Zhaozhou, Shuangcheng, Wuchang, Wuchang, Nahe, Bei’an, Gannan, Fuyu, Longjiang, Hei he, Qinggang* and Hailin*. Note: The design design seismic seismic group of all all cities of the county county level level and above above in allover the the provinces provinces belong to Group 1
A.0.8
1
Jiangsu Province The place-names place-names assigned to Intensity 8 with the design basic acceleration of of ground motion
equal to 0.30g: Group 1: Suqian, (Sucheng, Suyu*) 2
The place-names place-names assigned to Intensity 8 with the design basic acceleration of of ground motion 160
equal to 0.20g: Group 1: Xinyi, Pizhou and Suining 3
The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.15g: Group 1: Yangzhou (Weiyang, Guangling, Kanjiang), Zhenjiang (Jingkou, Runzhou), Sihong, Jiangdu. Group 2: Donghai, Shuyang and Dafeng 4
The place-names place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.1 0g: Group 1: Nanjing (Xuanwu, Baixia, Qinhuai, Jianye, Gulou, Xiaguan, Pukou, Liuhe, Qixia, Yuhuatai, Jiangning), Changzhou(Xinbei, Zhonglou, Tianning, Qishuyan,Wujin), Taizhou (Hailing, Gaogang), Jiangpu, Dongtai, Hai’an, Jiangyan, Rugao, Yangzhong, Yangzhong, Yizheng, Xinghua, Gaoyou, Liuhe, Jurong, Danyang, Jintan, Zhenjiang(Dantu), Liyang, Lishui, Kunshan and Taicang. Taicang. Group 2: Xuzhou (Longyun, Gonglou, Jiuli, Jiawang, Quanshan), Tongshan, Peixian, Huai’an (Qinghe, Qingpu, Huayin), Yancheng Yancheng (Tinghu, Yandu), Yandu), Siyang, Xuyi, Sheyang, Ganyu, Rudong. Group 3: Lianyungang (Xinpu, Lianyun, Haizhou) and Guanyun. 5
The place-names place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Group 1: Wuxi (Chong’an, Nanchang, Beitang, Binhu, Huishan), Suzhou (Jinchang, Canglang, Pingjiang, Huqiu, Wuzhong, Xiangcheng), Yixing, Changshu, Wujiang, and Taixing and Gaochun Group 2: Nantong (Chongchuan, Gangzha), Haimen, Qidong, Tongzhou, Zhangjiagang, Jingjiang, Jiangyin, Wuxi (Xishan), Jianhu, Hongze and Fengxian. Group 3: Xiangshui, Binhai, Funing, Baoying, J inhu, Guannan, Lianshui and Chuzhou. A.0.9
1
Zhejiang Province The place-names place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Daishan, Chengsi, Zhoushan (Dinghai, Putuo) and Ningbo (Beicang, Zhenhai) 2
The place-names place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Group 1: Hangzhou (Gongshu, Shangcheng, Xiacheng, Jianggan, Xihu, Binjiang, Yuhang, Xiaoshan), Ningbo(Haishu, Jiangdong, Jiangbei, Jinzhou), Huzhou(Wuxing, Huzhou(Wuxing, Nanxun), Jiaxing (Nanhu, Xiuzhou), Wenzhou (Lucheng, Longwan, Ouhai), Shaoxing, Shaoxing County, Changxing, Anji, Lin’an, Fenghua, Xiangshan, Deqing, Jiashan, Pinghu, Haiyan, Tongxiang, Haining, Shangyu, Cixi, Yuyao, Fuyang, Pingyang, Cangnan, Leqing, Yongjia, Taishun, Jingning, Yunhe and Dongtou. Group 2: Qingyuan, Rui’an A.0.10
Anhui Province 161
1
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 1: Wuhe, Sixian. 2
The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.10g: Group 1: Hefei (Shushan, Luyang, Yaohai, Baohe), Bengbu (Bengshan, Longzihu, Yuhui, Shuaishan), Fuyang (Yingzhou , Yingdong, Yingquan), Huainan (Tianjia’an, Datong), Zongyang, Huaiyuan, Changfeng, Liu’an (Jin’an, Yu’an), Guzhen, Fengyang, Mingguang, Dingyuan, Feidong, Feixi, Shucheng, Lujiang, Tongcheng, Huoshan, Woyang, Anqing (Daguan, Yingjiang, Yixiu) and Tongling County*. Group 2: Lingbi 3
The place-names place-names assigned to Intensity 6 with the design basic acceleration of of ground motion
equal to 0.05g: Group 1: Tongling (Tongguangshan, Shizishan, Suburb), Huainan (Xiejiaji, Bagongshan, Panji), Wuhu (Jinghu, Gejiang, Sanjiang, Jiujiang), Ma’anshan (Huashan, Yushan, Jinjiazhuang),Wuhu County, Taihe, Linquan, Funan, Lixin, Fengtai, Shouxian, Yingshang, Huoqiu, Jinzhai, Hanshan, Hexian, Dangtu, Wuwei, Fanchang, Chizhou, Yuexi, Yuexi, Qianshan, Taihu, Huaining, Wangjiang, Dongzhi, Susong, Nanling, Xuancheng, Langxi, Guangde, Jingxian, Qingyang a nd Shitai. Group 2: Chuzhou (Langya, Nanjiao), Lai’an, Quanjiao, Dangshan, Xiaoxian, Mengcheng, Haozhou, Chaohu, Tianchang. Group 3: Suixi, Huaibei and Suzhou A.0.11
1
Fujian Province The place-names place-names assigned to Intensity 8 with the design basic acceleration of of ground motion
equal to 0.20g: Group 2: Jinmen* 2
The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.15g: Group 1: Zhangzhou (Xiangcheng, Longwen), Dongshan, Zhaoan and Longhai. Group 2: Xiamen (Siming, Haicang, Huli, Jimei, Tong’an, Xiang’an), Jinjiang, Shishi, Changtai and Zhangpu. Group 3: Quanzhou (Fengze, Licheng, Luojiang and Quangang). 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion motion
equal to 0.10g: Group 2: Fuzhou (Gulou, Taijiang, Taijiang, Cangshan, Jin’an), Hua’an, Nanjing, Pinghe and Yunxiao. Yunxiao. Group 3: Putian (Chengxiang, Hanjiang, Licheng, Xiuyu), Changle, Fuqing, Pingtan, Hui’an, Nan’an, An’xi and Fuzhou (Mawei). 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion motion 162
equal to 0.05g: Group 1: Sanming (Meilie, Sanyuan), Pingnan, Xiapu, Fuding, Fu’an, Tuorong, Shouning, Zhouning, Songxi, Ningde, Gutian, Luoyuan, Shaxian, Youxi, Minqing, Minhou, Nanping, Datian, Zhangping, Longyan, Taining, Ninghua, Changding, Wuping, Jianning, Jiangle, Mingxi, Qingliu, Liancheng, Shanghang, Yong’an Yong’an and Jian’ou. Group 2: Zhenghe, Yongding. Group 3: Lianjiang, Yongtai, Yongtai, Dehua, Yongchun, Yongchun, Xianyou and Mazu. A.0.12
1
Jiangxi Province The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.1 0g: Xunwu and Huichang 2
The place-names place-names assigned to Intensity 6 with the design basic acceleration of of ground motion
equal to 0.05g: Nanchang (East Lake, West Lake, Qingyunpu, Wanli, Qingshanhu), Nanchang County, County, Jiujiang (Xunyang, Lushan Mountain), Jiujiang County, Jinxian, Yugan, Pengze, Hukou, Xingzi, Ruichang, De’an, Duchang, Wuning, Xiushui, Jing’an, Tonggu, Yifeng, Ningdu, Shicheng, Ruijin, Anyuan, Dingnan, Longnan, Quannan and Dayu. Note: The design design seismic seismic group of all all cities of the county county level level and above above in allover the the provinces provinces belong to Group l
A.0.13 Shandong Province
1
The place-manes assigned to Intensity not less than 8: with the design design basic acceleration of
ground motion equal to 0.20g: Group 1: Tancheng, Linmu, Lvnan, Lvxian, Yishui, Yishui, Anqiu, Yanggu, Yanggu, and Linyi Li nyi (Hedong) 2
The place-names place-names assigned to Intensity 7 with the design basic acceleration of of ground motion
equal to 0.1 5g: Group1:Linyi (Lanshan, Luozhuang), Qingzhou, Linju, Heze, Donging, Liaocheng, Shenxian and Juancheng, Group 2: Weifang (Kuiwen, Weicheng, Hanting, Fangzi), Cangshan, Yinan, Changyi, Changle, Zhucheng, Wulian, Changdao, Penglai, Longkou, Zaozhuang (Tai’erzhuang), Zibo (Linzi*) and Shouguang* 3
The place-names place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Yantai (Laishan, Zhifu, Muping), Weihai, Wendeng, Gaotang, Renping, Dingtao and Chengwu. Group 2: Yantai (Fushan), Zaozhuang, (Xuecheng, Shizhong, Yicheng, Shanting*), Zibo (Zhangdian, Zichuan, Zhoucun), Pingyuan, Dong’e, Pingyin, Liangshan, Yuncheng, Juye, Caoxian, Guangrao, Boxing, Gaoqing, Yuantai, Mengyin, Feixian, Huishan, Yucheng, Guanxian, Danxian*, Xiajin* and Laiwu (Laicheng*, Gangcheng) 163
Group 3: Dongying (Dongying district, Hekou), Rizhao (Donggang, Lanshan), Yiyuan, Zhaoyuan, Xintai, Qixia, Laizhou, Rizhao, Pingdu, Gaomi, Kenli, Zibo (Boshan), Bingzhou* and Pingyi*. 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion motion
equal to 0.05g: Group 1: Rongcheng Group 2: Dezhou, Ningyang, Q ufu, Zoucheng, Yutai, Yutai, Rushan and Yanzhou. Yanzhou. Group 3: Ji’nan (Shizhong, Lixia, Huaiyin, Tianqiao, Licheng, Changqing), Qingdao (Shinan, Shibei, Sifang, Huangdao, Laoshan, Chengyang, Licang), Tai’an (Taishan, Daiyue), Ji’ning (Shizhong,Rencheng), Leling, Qingyun, Wuli, Yangxin, Ningjin, Zhanhua, Lijin, Huimin, Shanghe, Linyi, Jiyang, Qihe, Zhangqiu, Sihui, Laiyang, Haiyang, Jinxiang, Tengzhou, Laixi, Jimo Jiaonan, Jiaozhou, Dongping, Wenshang, Wenshang, Jiaxiang, Linqing, Feicheng, Lingxian and Zouping. Henan Province
A.0.14
1
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion motion
equal to 0.20g: Group 1: Xinxiang (Weibin, Hongqi, Fengquan, Muye), Xinxiang County, Anyang (Beiguan, Wenfeng, Yindou, Long’an), Anyang County, Qixian, Weihui, Huixian, Yuanyang, Yanjin, Huojia and Fanxian. Group 2: Hebi (Qibin, Shancheng*, Heshan*) and Tangyin. Tangyin. 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion motion
equal to 0.15g: Group 1: Taiqian, Nanle, Shanxian, Wuzhi. Group 2: Zhengzhou (Zhongyuan, Erqi, Guancheng, Jinshui, Huiji), Puyang, Puyang County, Changyuan, Fengqiu, Xiuwu, Wuzhi, Neihuang, Xunxian, Huanxian, Qingfeng, Lingbao, Sanmenxia, Jiaozuo (Macun*) and Linzhou*. 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion motion
equal to 0.10g: Group 1: Nanyang (Wolong, (Wolong, Wancheng), Wancheng), Xinmi, Changge, Xuchang* and Xuchang County. Group 2: Zhengzhou (Shangjie), Xinzheng, Luoyang(Xigong, Laocheng, Chanhe, Jianxi, Jili, Luolong*), Jiaozuo (Jiefang, Shanyang, Zhongzhan), Kaifeng (Gulou, Longting, Shunhe, Yuwangtai, Jinming), Kaifeng County, Minquan, Lankao, Mengzhou, Mengjin,Gongyi, Yanshi, Qinyang, Boai, Jiyuan, Yingyang, Wenxian, Wenxian, Zhongmou and Qixian*. 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion motion
equal to 0.05g: Group 1: Xinyang (Shihe, Pingqiao), Luohe(Yancheng,Y Luohe(Yancheng,Yuanhui,Zhaoling), uanhui,Zhaoling), Pingdingshan (Xinhua, Weidong, Zhanhe, Shilong), Ruyang, Yuzhou, Baofeng, Yanling, Fugou, Taikang, Luyi, Dancheng, Shenqiu, Xiangcheng, Huaiyang, Zhoukou, Shangshui, Shangcai, Linying, Xihua, Xiping, Luanchuan, Neixiang, Zhenping, Tanghe, Tanghe, Dengzhou, Xinye, Sheqi, Pingyu, Xinxian, Zhumadian, Biyang, Ru’nan, Tongbai, Huaibing, Xixian, Zhengyang, Suiping, Guangshan, Luoshan, Huangchuan, Shangcheng, 164
Gushi, Nanzhao, Yexian* and Wuyang* Group 2: Shangqiu (Liangyuan, Juyang), Yima, Xin’an, Xiangcheng, Jiaxian, Congxian, Yiyang, Yichuan, Dengfeng, Zhecheng, Weishi, Tongxu, Yucheng, Xiayi and Ningling. Group 3: Ruzhou, Suixian, Yongcheng, Lushi, Luoning and Mianchi. A.0.15
1
Hubei Province The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Zhuxi, Zhushan and Fangxian 2
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Wuhan (Jiang’an, Hanjiang, Qiaokou, Hanyang, Wuchang, Qingshan, Hongshan, Dongxi Lake, Hannan, Caidian, Jiangxia, Huangbei, Xinzhou), Jingzhou (Shashi, Jingzhou), Jingmen(Dongbao, Duodao), Xiangfan (Xiangcheng, Fancheng, Xiangyang), Shiyan (Maojian, Zhangwan), Yichang (Xiling, Wujianggang, Dianjun, Xiaoting, Yiling), Huangshi (Xialu, Huangshigang, Xisaishan, Tieshan), Enshi, Xianning, Macheng, Tuanfeng, Luotian, Yingshan, Huanggang, E’zhou, Xishui, Qinchun, Huangmei, Wuxue, Yunxi, Yunxian, Danjiangkou, Gucheng, Laohekou, Yicheng, Nanzhang, Baokang, Shennongjia, Zhongxiang, Shayang, Yuan’an, Xingshan, Badong, Zigui, Dangyang, Jianshi, Lichuan, Gong’an, Xuan’en, Xianfeng, Changyang, Jiayu, Dazhi, Yidu, Zhijiang, Songzi, Jiangling, Shishou, Jianli, Honghu, Xiaogan, Yingcheng, Yunmeng, Tianmen, Xiantao, Hong’an, Anlu, Qianjiang, Jiayu, Tongshan, Chibi, Chongyang, Tongcheng, Wufeng* and Jingshan*. Note: The design seismic group of all cities of the county level and above in all over the provinces belong to Group 1.
A.0.16
1
Hunan Province The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Changde (Wuling, Dingcheng) 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Yueyang (Yueyang Tower, Junshan Moutain *), Yueyang County, Miluo, Xiangyin, Linli, Lixian, Jinshi, Taoyuan, Anxiang and Hanshou 3
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Changsha (Yuelu, Furong, Tianxin, Kaifu, Yuhua), Changsha County, Yueyang(Yunxi), Yiyang (Heshan, Ziyang), Zhangjiajie (Yongding, Wulingyuan), Chenzhou (Beihu,Suxian), Shaoyang (Daxiang,Shuangqing,Beita), Shaoyang County, Luxi, Ruanling, Loudi, Yizhang, Zixing, Pingjiang, Ningxiang, Xinhua, Lengshijiang, Lianyuan, Shuangfeng, Xinshao, Shaodong, Longhui, Shimen, Cili, Huarong, Nanxian, Linxiang, Ruanjiang, Taojiang, Wangcheng, Xupu, Huitong, Jingzhou, Shaoshan, Jianghua, Ningyuan, Daoxian, Linwu, Xiangxiang*, Anhua*, Zhougfang* and Hongjiang* Note: The design seismic group of all cities of the county level and above in allover the provinces belong to Group 1. 165
Guangdong Province
A.0.17
1
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Shantou (Jinping, Haojiang, Longhu, Chenghai), Chaoan, Nan’ao, Xuwen and Chaozhou* 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Jieyang, Jiedong, Shantou (Chaoyang, Chaonan) and Raoping 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Guangzhou (Yuexiu, Liwan, Haizhu, Hetian, Baiyun, Huangpu, Fanyu, Nansha, Luogang), Shenzhen (Futian, Luohu, Nanshan, Bao’an, Yantian), Zhanjiang (Chikan, Xiashan, Potou, Mazhang), Shanwei, Haifeng, Puning, Huilai, Yangjiang, Yangdong, Yangxi, Maoming (Maonan, Maogang), Huazhou, Lianjiang, Suixi, Wuchuan, Fengshun, Zhongshan, Zhuhai (Xiangzhou, Doumen, Jinwan) Dianbai, Leizhou, Foshan (Shunde, Nanhai, Chancheng*), Jiangmen (Pengjiang, Jianghai, Xinhui*) and Lufeng* 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Shaoguan (Zhenjiang, Wujiang, Qujiang), Zhaoqing (Duanzhou, Dinghu), Guangzhou (Huadu) , Shenzhen (Yougang), Heyuan, Jiexi, Dongyuan, Meizhou, Dongguan, Qingyuan, Qingxin, Nanxiong, Renhua, Shixing, Ruyuan, Yingde, Fogang, Longmen, Longchuan, Pingyuan, Conghua, Mei County, Xingning, Wuhua, Zijin, Luhe, Zengcheng, Boluo, Huizhou (Huicheng,Huiyang), Huidong, Sihui, Yunfu, Yun’an, Gaoyao, Foshan, (Sanshui,Gaoming), Heshan, Fengkai, Yunan, Luoding, Xinyi, Xinxing,
Kaiping,
Enping,
Taishan,
Yangchun,
Gaozhou,
Wengyuan,
Lianping,
Heping,
Jiaoling ,Dapu and Xinfeng* Note: The design seismic group of all cities of the county level and above in all over the provinces (except Dapu belongs to Group 2) belong to Group 1.
A.0.18
1
Guangxi Zhuangzu Autonomous Region The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Lingshan, Tiandong 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Yulin, Xingye, Hengxian, Beiliu, Baise, Tianyang, Pingguo, Longan, Pubei, Bobai and Leye* 3
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Nanning (Qingxiu, Xingning, Jiangnan, Xitangxiang, Liangqing, Yongning), Guilin (Xiangshan, Diecai, Xiufeng, Qixing, Yanshan), Liuzhou (Liubei, Chengzhong, Yufeng, Liunan), Wuzhou (Changzhou, Wanxiu, Dieshan), Qinzhou (Qingnan, Qingbei), Guigang (Gangbei, Gangnan), 166
Fangchenggang (Gangkou,Fangcheng), Beihai (Haicheng,Yinhai), Xing’an, Lingchuan, Lingui, Yongfu, Luzhai, Tian’e, Donglan, Bama, Du’an, Dahua, Mashan, Rong’an, Xiangzhou, Wuxuan, Guiping, Pingnan, Shanglin, Binyang, Wuming, Daxin, Fusui, Dongxing, Hepu, Zhongshan, Hezhou, Tengxian, Cangwu, Rongxian, Cenxi, Luchuan, Fengshan, Lingyun, Tianlin, Longlin, Xilin, Debao, Jingxi, Napo, Tiandeng, Chongzuo, Shangsi, Longzhou, Ningming, Rongshui, Pingxiang and Quanzhou Note: The design seismic group of all cities of the county level and above in all over the autonomous region belong to Group 1.
A.0.19
1
Hainan Province The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.30g: Haikou (Longhua, Xiuying, Qiongshan, Meilan), 2
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Wenchang, Ding’an 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Chengmai 4
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Lingao, Qionghai, Chanzhou and Tunchang 5
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Sanya, Wanning, Changjiang, Baisha, Baoting, Lingshui, Dongfang, Ledong, Wuzhishan, and Qiongzhong Note: The design seismic group of all cities of the county level and above in all over the provinces (except Tunchang and Qiongzhong belongs to Group 2) belong to Group 1.
A.0.20
1
Sichuan Province The place-manes assigned to Intensity not less than 9 with the design basic acceleration of
ground motion not less than 0.40g: Group 2: Kangding, Xichang 2
The place-manes assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0. 30g: Group 2: Mianning* 3
The place-manes assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0. 20g: 167
Group 1: Maoxian, Wenchuan and Baoxing Group 2: Songpan, Pingwu, Beichuan, Dujiangyan, Daofu, Luding, Ganzi, Luhuo, Xide, Puge, Ningnan, Litang. Group 3: Jiuzhaigou, Shimian and Dechang 4
The place-manes assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 2: Batang, Dege, Mabian, Leibo, Tianquan, Lushan, Danba, Anxian, Qingchuan, Ji angyou, Mianzhu, Shifang, Pengzhou, Lixian and Jiange* Group 3: YingJing, Hanyuan, Zhaojue, Butuo, Ganluo, Yuexi, Yajiang, Jiulong, Muli, Yanyuan, Huidong and Xinlong. 5
The place-manes assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group l: Zigong (Ziliujing, Da’an, Gongjing, Yantan), Group 2: Mianyang (Fucheng, Youxian), Guangyuan (Lizhou, Yuanba, Chaotian), Leshan (Shizhong, Shawan), Yibin, Yibin County, E’bian, Muchuan, Pingshan, Derong, Ya’an, Zhongjiang, Deyang, Luojiang, Emeishan Moutain and Maerkang. Group 3: Chengdu (Qingyang, Jinjiang, Jinniu, Wuhou, Chenghua, Longzequan, Qingbaijiang, Xindu, Wenjiang,), Panzhihua (East, West and Renhe), Ruoergai, Seda, Rangtang, Shiqu, Baiyu, Yanbian, Miyi, Xiangcheng, Daocheng, Shuangliu, Leshan (Jinkouhe,Wutongqiao),Mingshan, Meigu, Jinyang, Xiaojin, Huili, Heishui, Jinchuan, Hongya, Jiajiang, Qionglai, Pujiang, Pengshan, Danling, Meishan, Qingshen, Pi County, Dayi, Chongzhou, Xinjin, Jintang and Guanghan 6
The place-manes assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0. 05g: Group 1: Luzhou (Jiangyang, Naxi, Longmatan), Neijiang (Shizhong, Dongxing), Xuanhan, Dazhou, Daxian, Dazhu, Linshui, Quxian, Guangan, Huaying, Longchang, Fushun, Nanxi, Xingwen, Xuyong, Gulin, Zizhong, Tongjiang, Wanyuan, Bazhong, Langzhong, Yilong, Xichong, Nanbu, Shehong, Daying , Lezhi and Ziyang Group 2: Nanjiang, Cangxi, Wangcang, Yanting, Santai, Janyang, Luxian, Jiang’an, Changning, Gaoxian, Gongxian, Renshou and Weiyuan; Group 3: Qianwei, Rongxian, Zitong, Junlian, Jingyan, A’ba, Hongyuan A.0.21
1
Guizhou Province The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Wangmo Group 3: Weining 2
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: 168
Group 1: Guiyang (Wudang*, Baiyun*, Xiaohe, Naming, Yunyan, Huaxi), Kaili, Bijie, Anshun, Dujun, Huangping, Fuquan, Guiding, Majiang, Qingzhen, Longli, Pingba, Nayong, Zhijin, Puding, Liuzhi, Zhenning, Huishui, Changshun, Guanling, Ziyun, Luodian, Xingren, Zhenfeng, An’long, Jinsha, Yinjiang, Chishui, Xishui and Sinan*. Group 2: Liupanshui, Shuicheng, Shanheng; Group 3: Hezhang, Pu’an, Qinglong, Xingyi, Panxian A.0.22
1
Yunnan Province The place-names assignedto Intensity 9 with the design basic acceleration of ground motion
equal to 0.40g: Group 2: Xundian, Kunming (Dongchuan) Group 3: Lancang 2
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.30g: Group 2: Jianchuan, Songming, Yiliang, Lijiang, Yulong, Heqing, Yongsheng, Luxi, Longling, Shiping, Jianshui; Group 3: Gengma, Shuangjiang, Cangyuan, Menghai, Ximeng, Menglian 3
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 2: Shilin, Yuxi, Dali, Qiaojia, Jiangchuan, Huaning, E’shan, Tonghai, Eryuan, Binchuan, Midu, Xiangyun, Huize and Nanjian Group 3: Kunming, (Panlong,Wuhua,Guandu,Xishan), Puer, Baoshan, Malong, Chenggong, Chengjiang, Jinning, Yimen, Yangbi, Weishan, Yunxian, Tengchong, Shidian, Ruili, Lianghe, Anning, Jinhong, Yongde, Zhenkang, Lincang, Fengqing* and Longchuan* 4
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 2: Shangri-la, Lushui, Daguan, Yongshan, Xinping* Group 3: Qujing, Mile, Luliang, Fumin, Luquan, Wuding, Lanping, Yunlong, Jinggu, Ninger, Zhanyi, Gejiu, Honghe, Yuanjiang, Lufeng, Shuangbai, Kaiyuan, Yingjiang, Yongping, Changning, Ninglang, Nanhua, Chuxiong, Mengla, Huaping and Jingdong* 5
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 2: Yanjing, Suijiang, Deqin, Gongshan and Shuifu; Group 3: Zhaotong, Yiliang, Ludian, Fugong, Yongren, Dayao, Yuanmou, Yaoan, Mouding, Mojiang, Luchun, Zhenyuan, Jiangcheng, Jinping, Fuyuan, Shizong, Luxi, Mengzi, Yuanyang, Weixi and Xuanwei 6
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: 169
Group 1: Weixin, Zhenxiong, Funing, Xichou, Malipo and Maguan Group 2: Guangnan Group 3: Qiubei, Yanshan, Pingbian, Hekou, Wenshan and Luoping A.0.23
1
Xizang Autonomous Region The place-names assigned to Intensity 9 with the design basic acceleration of ground motion
equal to 0.40g: Group 3: Dangxiong, Motuo 2
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.30g: Group 2: Shenzha Group 3: Milin and Bomi 3
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 2: Pulan, Nielamu and Saga Group 3: Lasa, Duilongdeqing, Nimu, Renbu, Nima, Luolong, Longzi, Cuona, Qusong, Naqu, Linzhi (Bayi Town) and Linzhou 4
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 2: Zhada, Jilong, Lazi, Xietongmen, Yadong, Luozha and Angren Group 3: Ritu, Jiangzi, Kangma, Bailang, Zhanang, Cuomei, Sangri, Jiazha, Bianba, Basu, Dingqing, Leiwuqi, Naidong, Qiongjie, Gongga, Lang County, Dazi, Nanmulin, Bange, Langkazi, Mozhugongka, Qushui, An’duo, Nierong, Rikeze* and Gaer* 5
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Gaize Group 2: Cuoqin, Zhongba, Dingjie and Mangkang Group 3: Changdu, Dingri, Sajia, Gangba, Baqing, Gongbujiangda, Suo County, Biru, Jiali, Chaya, Zuogong, Chayu, Jiangda and Gongjue 6
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Group 2: Geji A.0.24
1
Shaanxi Province The place-manes assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 1: Xi’an (Weiyang, Lianhu, Xincheng, Beilin, Baqiao, Yanta, Yanliang*, Lintong), Weinan, 170
Huaxian, Huayin, Tongguan and Dali Group 3: Long County 2
The place-manes assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 1: Xianyang (Xindu, Weicheng), Xi’an (Chang’an), Gaoling, Xingping, Zhouzhi, Luhu and Lantian Group 2: Baoji (Jintai, Weibin, Chencang), Xianyang (Yangling Special Region), Qianyang, Qishan, Fengxiang, Fufeng, Wugong, Meixian, Sanyuan, Fuping, Chengcheng, Pucheng, Jingyang, Liquan, Hancheng, Heyang and Lueyang Group 3: Feng County 3
The place-manes assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Ankang and Pingli Group 2: Luonan, Qian County, Mian County, Ningqiang, Nanzheng and Hanzhong, Group 3: Baishui, Chunhua, Linyou, Yongshou, Shangzhou (Shangzhou), Taibai, Liuba, Tongchuan (Yaozhou, Wangyi, Yintai*) and Zhashui*, 4
The place-manes assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Group 1: Yan’an, Qingjian, Shenmu, Jiaxian, Mizhi, Suide, Ansai, Yanchuan, Yanchang, Zhidan, Ganquan, Shangnan, Ziyang, Zhenba, Zichang* and Zizhou* Group 2: Wuqi, Fuxian, Xunyang, Baihe, Langao and Zhenping Group 3: Dingbian, Fugu,Wubao, Luochuan, Huangling, Xunyi, Yangxian, Xixiang, Shiquan, Hanyin, Ningshan Chenggu ,Yichuan, Huanglong, Yijun, Changwu, Binxian, Foping, Zhen’an, Danfeng and Shanyang A.0.25
1
Gansu Province The place-manes assigned to Intensity not less than 9 with the design basic acceleration of
ground motion not less than 0.40g: Group 2: Gulang 2
The place-manes assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.30g: Group 2: Tianshui (Qinzhou, Maizhi), Lixiann and Xihe. Group 3: Baiyin (Pingchuan District) 3
The place-manes assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 2: Dangchang, Subei, Longnan, Cheng County, Hui County, Kang County and Wen County 171
Group 3: Lanzhou (Chengguan, Qilihe, Xigu, Anning), Wuwei, Yongdeng, Tianzhu, Jingtai, Jingyuan, Longxi, Wushan, Qin’an, Qingshui, Gangu, Zhang County, Huining, Jingning, Zhuanglang, Zhangjiachuan, Tongwei, Huating, Liangdang and Zhouqu 4
The place-manes assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 2: Kangle, Jiayuguan, Yumen, Jiuquan, Gaotai, Linze and Sunan Group 3: Baiyin (Baiyin District), Yongjing(Honggu District), Yongjing, Minxian, Dongxiang, Hezheng, Guanghe, Lintan, Zhuoni, Diebu, Linzhao, Weiyuan, Gaolan, Chongxin, Yuzhong, Dingxi, Jinchang, Akesai, Minle, Yongchang and Pingliang 5
The place-manes assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 2: Zhangye, Hezuo, Maqu and Jinta Group 3: Dunhuang, Guazhou, Shandan, Li nxia, Linxia County, Xiahe, Luqu, Jingchuan, Lingtai, Minqin, Zhenyuan, Huan county and Jishishan 6
The place-manes assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Group 3: Huachi, Zhengning, Qingyang, Heshui, Ningxian and Xifeng A.0.26
1
Qinghai Province The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 2: Maqin Group 3: Maduo and Dari 2
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 2: Qilian Group 3: Gande, Menyuan, Zhiduo and Yushu 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 2: Wulan, Zhiduo, Zaduo and Nangqian Group 3: Xining (middle, east, west, north), Tongren, Gonghe, Delingha, Haiyan, Huangyuan, Huangzhong, Ping’an, Minhe, Hualong, Guide, Jianzha, Xunhua, Geermu, Guinan, Tongde, Henan, Qumacai, Jiuzhi, Banma, Tianjun, Gangcha, Datong, Huzhu, Leduo, Dulan and Xinghai 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0. 05g: Group 3: Zeku A. 0. 27 Ningxia Autonomous Region 172
1
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0. 30g: Group 2: Haiyuan 2
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0. 20g: Group 1: Shizuishan (Dawukou, Huinong) and Pingluo Group 2: Yinchuan (Xingqing, Jinfeng, Xixia), Wuzhong, Helan, Yongning, Qingtongxia, Jingyuan, Lingwu, Guyuan Group 3: Xiji, Zhongning, Zhongwei, Tongxin and Longde 3
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g : Group 3: Pengyang. 4
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0. 05g: Group 3: Yanchi A.0.28
1
Xinjiang Autonomous Region The place-names assigned to Intensity 9 with the design basic acceleration of ground motion
no less than 0. 40g: Group 3: Wuqia and Tashikuergan 2
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.30g: Group 3: Atushi, Kashi and Shufu 3
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 1: Balikun Group 2: Urumqi (Tianshan Mountain, Shayibake, Xinshi, Shuimogou, Toutunhe, and Midong), Urumqi County, Wensu, Akesu, Keping, Zhaosu, Tekesi, Kuche, Qinghe, Fuyun and Wushi Group 3: Nileke, Xinyun, Gongliu, Jinghe, Wusu, Kuitun, Shawan, Manasi, Shihezi, Kelamayi (Dushanzi), Shule, Jiashi, Aketao and Yingjisha 4
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 1: Mulei* Group 2: Kuerle, Xinhe, Luntai, Hejing, Yanqi, Bohu, Bachu, Baicheng, Changji and Fukang* Group 3: Yining, Yining County, Huocheng, Hutubi, Chabuchaer and Yuepuhu 5
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion 173
eaual 0.10g: Group 1: Shanshan Group 2: Urumqi (Dabancheng), Tulufan, Hetian, Hetian county, Jimusaer, Luopu, Qitai, Yiwu, Tuokexun, Heshuo, Weili, Moyu, Zele and Hami* Group 3: Wujiaqu, Kelamayi (Kalamayi District), Bole, Wenquan, Aheqi, Awati, Shaya, Tumushuke, Shache, Zepu, Yecheng, Maigaiti and Pishan 6
The place-names assigned to Intensity 6 with the design basic acceleration of ground motion
equal to 0.05g: Group 1: Emin and Hebukesaier Group 2: Yutian, Habahe, Tacheng, Fuhai and Kelamayi (Maersu) Group 3: Aletai, Tuoli, Minfeng, Ruoqiang, Buerjing, Jibunai, Yumin, Kelamayi (Baijiantan), Qiemo and Alaer A.0.29
1
Hongkong, Macao Special District and Taiwan Province The place-names assigned to anti-earthquake precautionary Intensity with no less than
Intensity 9 and with the design basic acceleration of ground motion no less than 0.40g: Group 2: Taizhong Group 3: MiaoLi, Yunlin, Jiayi and Hualian 2
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.30g: Group 2: Tainan Group 3: Taibei, Taoyuan, Jilong, Yilan, Tandong and Pingdong 3
The place-names assigned to Intensity 8 with the design basic acceleration of ground motion
equal to 0.20g: Group 3: Gaoxiong and Penghu 4
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.15g: Group 1: Hongkong 5
The place-names assigned to Intensity 7 with the design basic acceleration of ground motion
equal to 0.10g: Group 1: Macao
174
Appendix B
Requirements for Seismic Design of High Strength Concrete Structures
B.0.1
The concrete Grade adopted in the high strength concrete structures shall meet the
requirements in Article 3.9.3 of this code. And the seismic design of these structures, besides complying with the requirements for seismic design of common concrete structures, shall also meet the requirements in this Appendix. B.0.2
In formulae for cross-sectional shear capacity design limit values of structural component, the
terms that contain specified concrete compressive strength ( f c) shall be multiplied with the concrete strength factor ( β c). The β c shall be taken as 1.0 for the concrete strength Grade C50, taken as 0.8 for the strength Grade C80, and taken as the interpolation value for between the strength Grade C50 and C80. When calculating the compressive zone height or checking the bearing capacity of structural component, terms in the formula that contain the specified concrete compressive strength ( f c) shall be multiplied by corresponding concrete strength coefficients. They are as per specified in relevant provisions in the national standard “Code for Design of Concrete Structures” GB 50010. B.0.3
The details of seismic design of high strength concrete frames shall meet the following
requirements: 1
The reinforcement ratio for the longitudinal tensile reinforcement at the end of the beam
should not be larger than 3% (HRB335 reinforcement) or 2.6% (HRB400 reinforcement). The minimum diameter of the hoops in the densified hoop ranges at the end of the beam shall increase 2mm than the minimum diameter of reinforcement used for common reinforced concrete beams. 2
The Axial-force-ratio limit value of the column should be adopted according to the following
provisions: for the strength Grade less than and equal to C60, the limit value may be taken as that of common concrete columns; for the strength Grade C65 ~ C70, should reduce 0.05 than that; and for the strength Grade C75 ~ C80, should reduce 0.1 than that. 3
When the strength Grade of the concrete is larger than C60, the minimum total reinforcement
ratio for the longitudinal reinforcement of the column shall increase by 0.1% than that for common reinforced concrete columns. 4
The minimum hoop characteristic factors in the densified ranges of the column should be
adopted according to the following provisions. Meanwhile, for the concrete strength is larger than C60, the hoops shall adopt composite hoops, composite spiral hoops or continuous composite rectangular spiral hoops. 1)
When the Axial-force-ratio is not larger than 0.6, this value shall be 0.02 larger than that
for common concrete columns; 2)
When the Axial-force-ratio is larger than 0.6, this value shall be 0.03 larger than that for
common concrete columns. B.0.4
When the strength Grade of the concrete of seismic wall is larger than C60, reinforce
measures shall be taken according to special studies. 175
Appendix C
Seismic Design Requirements for Pre-stressed Concrete Structures
C.0.1
The provisions of this appendix shall be applied to the seismic designs of pre-tensioning
and/or post-tensioning bonded pre-stressed concrete structures for Intensity 6, 7 and 8; the special studies shall be carried out for Intensity 9. Measures shall be taken to prevent effective pre-applied force loosing in structural-component plastic hinge zone under rare earthquake action during seismic design of without-bond pre-stress concrete structure. C.0.2
Measures shall be taken to enable the pre-stressed concrete structure for seismic design to
endow with good deformation and sound ability to dissipate seismic energy; in addition, the tensile structure shall meet the basic requirements. It shall avoid that component shear failure is ahead of flexural failure; joint destroy comes before connected component destroy or pre-stress-tendon anchoring bond failure is in advance of component. C.0.3
During seismic design, with-bond pre-stress tendon should be adopted for posttensioning
pre-stress frame, portals and the transformation beam of transition-storey. without-bond pre-stress tendon shall not be adopted for the tension component of bearing structure and the seismic Grade 1 frame. C.0.4
During seismic design, the adjustment of pre-stressed-concrete-structure seismic Grade and
the corresponding seismic-combination internal stress shall be carried out according to the requirements stated about reinforced concrete structure in Chapter 6 of this code. C.0.5
Strength Grade of pre-stressed concrete structure, frames and transition component in
transition-storey should not be less than C40. Pre-stressed concrete components of other resistant lateral force shall not be less than C30. C.0.6
In addition to meet the provisions in Chapter 5 of this code, the seismic calculation of
pre-stressed concrete structure shall also meet the following provisions: 1
The damping ratio of pre-stressed concrete structure its own may be 0.03. Besides, the
proportion of reinforced concrete structure and pre-stressed concrete structure accounting for the total deformation may be converted into equivalent damping ratio. 2
During seismic checking of component section, pre-stress action effect shall be added in
fundamental combination of earthquake action effect in Article 5.4.1 of this code. The partial factor, shall be 1.0 in general and when pre-stress action effect is unfavorable to component bearing capacity, it is 1.2. 3
When pre-stress tendon goes through frame joint-core area, the seismic checking of joint core
area section shall be counted into influence of total effective pre-applied force as well as the effective checking width in pre-stress opening weaken core area. C.0.7
In addition to the following provisions, the seismic structure shall meet the requirements on
reinforced concrete structure in Chapter 6 of this code. 1
Lateral-force-resisting component shall be the mixture of pre-stress tendon and non-pre-stress 176
tendon. The ratio of these two shall be controlled according to seismic Grade and relevant provisions; in addition, the pre-stress strength ratio should not be greater than 0.75. 2
The maximum reinforcement ratio of tension reinforcement in longitudinal direction at the
end of frame beam as well as the ratio of bottom surface to top surface non-pre-stressed reinforcement shall be converted according to corresponding pre-stress strength ratio and the converted ratio shall meet the requirements of reinforced concrete frame beam. 3
Pre-stressed-concrete frame columns may be asymmetric reinforcement; thereof, the axial
force ratio calculation shall be counted into the axial-pressure design value generated by the total effective pre-applied force of pre-stress tendon and the calculation shall meet the corresponding requirements of frame column in reinforced concrete structure; in addition, stirrup should be desified in the total height. 4
In slab-column seismic wall, the requirements on going through bottom slab within column
section range shall be counted into pre-stressed-reinforcement sectional area. C.0.8
Anchorage of post-tensioning pre-stress tendon should not be arranged in beam or column
joint core area. The anchorage performance of pre-stress tendon-anchorage assembling component shall meet the special provisions.
177
Appendix D
Seismic Design for the Core Zone of Column-beam Joint of the Frame Structures D.1
D.1.1
Column-beam Joint of the Frame Structures
For frames assigned to Grade 1, 2 and 3, the combination shear force design value for the core
zone at the joint of beam and column shall be determined according to the following formulae:
V j=
η jbΣ M b hb 0 − a s′
(1 −
hb 0 − a s′ H c − hb
)
(D.1.1-1)
For Grade 1 framed-structures or Intensity 9 Grade 1 framed-structures may not be determined according to the aforementioned formula, but it shall conform to V j=
1.15Σ M bua hb 0 − a s′
(1 −
hb 0 − a s′ H c − hb
)
(D.1.1-2)
Where V j ——The combination shear force design value for the core zone at the joint of beam and column; h b0 ——The effective depth of the beam section, when the depths of the beam sections at the two sides of the joint are unequal, the average value may be adopted; a′s ——The distance measured from the compression beam to the centroid of compressive reinforcement of the beam; H c ——The calculated height of the column, which may adopt the distance of inflection points of the upper and lower columns on the joint; h b ——The depth of beam section, when the depths of the beam sections at the two sides of the joint are unequal, the average value may be adopted;
η jb ——Strong joint coefficient, as for framed structure, 1.5 for Grade 1, l.35 for Grade 2, 1.2 for Grade 3; as for other structures, l.35 for Grade 1, 1.2 for Grade 2 and 1.1 for Grade 3; ∑ M b ——The sum of the clockwise and counter-clockwise combined bending moments at the right and left ends of the joint; If the both bending moments at the left and right end of the joint are negative together for Grade 1, the bending moment with smaller absolute value shall choose zero; ∑ M bua ——Sum of moments in clockwise or counter-clockwise direction at the faces of the joint corresponding to actual seismic bending capacity of normal cross section of right and left beam ends of the joint, which may be determined by actual reinforcement area and standard value of the material strength. D.1.2
Effective checking width of the cross section at the core zone shall be adopted according to
the following provisions: 1
For the beam width at the checking direction is not less than 1/2 of the column width, the
effective bearing width of the cross section at the core zone may be taken as the width of column. And for that is less than 1/2, the smaller value of the following two cases may be adopted: 178
b j=b b+0.5hc
(D.1.2-1)
b j=bc Where,
(D.1.2-2)
b j ——The effective bearing width of the cross section at the core zone of the joint;
b b ——The width of beam cross-section; hc ——The depth of column cross-section at the checking direction; bc ——The width of column cross-section at the checking direction. 2
When the eccentricity between the axes of beam and the column is not larger than 1/4 of the
column width, such width may be taken as that, which is the smaller value between that provision in the above article and that obtained from the following formula: b j=0.5(b b+bc)+0.25hc-e
(D.1.2-3)
Where, e ——The eccentricity between both axes of the beam and column. D.1.3
The combination shear force design value of joint core zone shall meet the following
requirements:
V j≤
1
γ RE
(0.30η j f cb jh j)
(D.1.3)
Where η j —— The confined influence factor of the orthogonal beams. When the floor slab is cast-in-situ; the beam or column center lines superpose; sectional widths of four side beams being not less than 1/2 this lateral-column sectional width and orthogonal beam height is not less than 3/4 frame beam height, it may be 1.5; 1.25 for Intensity 9 and Grade 1; 1.0 for other conditions; h j ——Cross-sectional height at the core zone of the joint may adopt the column cross-sectional height at the checking direction; λRE ——Seismic adjusting factor for load-bearing capacity, may be taken as 0.85. D.1.4
The seismic shear bearing capacity of the cross section at the joint core zone shall be checked
according to the following formula:
V j≤
1
γ RE
For Grade 1 Intensity 9 V j≤
(1.1η j f tb jh j+0.05η j N
1
γ RE
(0.9η j f tb jh j+ f yv Asvj
b j bc
+ f yv Asvj
hb 0 − a s′ s
hb 0 − a s′
)
s
)
(D.1.4-1)
(D.1.4-2)
Where N ——The smaller axial compressive force of the upper column corresponds to the combination shear design value. Such value shall not be larger than 50% of production of the column cross section area and the specified concrete compressive strength design value; and when N is tensile force, shall take as zero; f yv ——Design value of specified tensile strength of hoop; f ——Design value of specified tensile strength of concrete axle center; t 179
Asvj ——Total hoop cross-sectional area within the same cross section at the checking direction within the effective checking width of the core zone; s ——Spacing of hoop. D.2 D.2.1
Column-beam Joint for Flat Beam Frames
When the beam width of flat beam frame is larger than the column width, the column-beam
joint shall conform to the provisions in this section. D.2.2
As for the beam & column joint core area of flat-beam frame, shear bearing capacity shall be
checked within and outside column width according to the sectional area ratio of beam longitudinal tendon inside and outside column width range. D.2.3
The seismic check for the core zone, besides satisfying the requirements for common frame
beam joint, shall also meeet the following requirements: 1
When checking the shear force limit value of the core zone according to formula (D.1.3) in
this Appendix, the effective width of the core zone may adopt the average value of column width and beam width. 2
As for there are beams at four sides, the confine factor for checking the shear bearing
capacity of the core zone within column with may be taken as 1.5, and for the beyond the range of the column width should be taken as 1.0. 3
When checking the shear bearing capacity of the core zone, the value of the axial force,
which within the range of the column width, may be the taken as same as the common joint; but that beyond the range of the column width may not be taken into consideration. 4
Reinforcement at the top of beam which is anchored into column should be greater than 60%
the total gross section area. D.3 D.3.1
Column-beam Joint for Cylinder Column Frame
When the axes of the beam and the column are concord, the combination shear force design
value of joint core zone for the cylinder column frame shall meet the following requirements:
V j≤
1
γ RE
(0.30η j f c A j)
(D.3.1)
Where η j ——The confined influence factor of orthogonal beam shall be determined according to Article D.1.3 of this Appendix, thereof the cross section width of column may be taken as the diameter of the column; A j ——The effective cross sectional area of the joint core zone. When the beam width (b b) is not less than 50% of the column diameter ( D), then A j=0.8 D2; when the beam width (b b) is less than 50% of the column diameter ( D) but not less than 0.4 D, then A j=0.8 D(b b+ D/2). D.3.2
When the axes of beam and column are concord, the seismic shear bearing capacity of joint
core zone the cylinder column frame shall be checked according to the following formulae:
V j≤
1
γ RE
(0.30η j f A t j+0.05η j
N D
2
A j+1.57 f yv Ash
hb 0 − a s′ s
+ f yv Asvj
hb 0 − a s′ s
) (D.3.2-1) 180
For Grade 1 Intensity 9
V j≤
1
γ RE
(1.2η j f A t j+1.57 f yv Ash
hb 0 − a s′ s
+ f yv Asvj
hb 0 − a s′ s
)
(D.3.2-2)
Where Ash ——Cross-sectional area of single circular hoop; Asvj ——Total cross sectional area of tie piece and non-circular hoops in the same sectional checking direction; D ——Column sectional diameter; N ——Axial force design value shall meet the requirements for common joint in this Appendix.
181
Appendix E E.1 E.1.1
Seismic Design for the Transition-storeys
Design Requirements of Rectangular Seismic Seismic wall with Frame-brace-floor Slab
The slab shall adopt cast-in-situ, the thickness should not be less than 180mm, the concrete
strength Grade should not be less than C30, two-way and double layer reinforcement shall be arranged, besides, the steel ratio of each storey in each direction shall not be less than 0.25%. E.1.2
The shear force design value of partial floor slab of frame-brace-seismic wall shall meet the
following requirements:
V f≤
1
γ RE
(0.1 f cbf t f )
(E.1.2)
Where V ——The combination shear force design value of the frame-brace floor slab transmitting f from un-grounding seismic wall to grounding seismic wall. That calculated by rigid floor assumption and shall be multiplied by the enhancement coefficient 2 for Intensity 8 and 1.5 for Intensity 7; for checking on the grounding seismic wall, such enhancement coefficient need not be considered; bf , t ——The width and thickness of the frame-brace floor slab respectively; f γRE ——Seismic adjusting factor for bearing capacity, may be taken as 0.85. E.1.3
The seismic shear capacity at the intersecting section of the frame-brace floor slab and the
grounding seismic wall in frame-support-seismic wall shall be checked in accordance with the following formula:
V f ≤
1
γ RE
( f y As)
(E.1.3)
Where, A ——The total reinforcement sectional areas of the frame-brace floor (including beam and s slab) that traverses the grounding seismic wall. E.1.4
Boundary beams shall be installed along the edge and the perimeters of larger openings in
frame-brace slab, its width shall not be less than 2 times of the slab thickness. The reinforcement ratio of longitudinal reinforcement shall not be less than 1%, and the connection of reinforcements in the beam should adopt mechanical connection or welded. The reinforcement in the slab shall be developed to the boundary beams. E.1.5
For the frame-brace slab with longer size plain or irregular in configuration or the internal
force of the seismic wall have big differences, the in-plane flexural and shear bearing capacity of the slab may also be checked by adopting simplification methods. E.2 E.2.1
Seismic Design Requirements for Transition-storey of Tube Structures
The structural gravity centers above and below the transition-storey should be coincident (the
podium is not included), and the lateral-rigidity-ratio of upper and lower transition storey should not be larger than 2. E.2.2
The vertical lateral-force-resisting components (seismic wall and/or columns) above the
transition-storey should be directly connected to the main structural components of the 182
transition-storey. E.2.3
The thick-slab-transition structure should not be used in tall buildings for Intensity 7 or above.
E.2.4
The transition roof shall not have larger openings, and should be close to rigidity in a plane.
E.2.5
Reliable connections shall be made between the transition-roof and the tube or seismic wall,
the seismic check and the structures of the transition slab should meet the relevant requirements in Section E.1 of this appendix. E.2.6
Vertical earthquake action for the transition-storey structures shall be considered for Intensity
8. E.2.7
The tube structure with transition-storey shall not be adopted for Intensity 9.
183
Appendix F
Seismic Design for R.C. Block Buildings F.1
F.1.1
General Requirements
The maximum height of the reinforced concrete small-sized hollow block seismic wall
buildings (hereinafter refer to R.C. block buildings) being applicable to this Appendix shall meet those specified in Table F.1.1-1. And the maximum ratio of the total height to total width of the building should not exceed the provisions in Table F.1.1-2.
Table F.1.1-1 Applicable Maximum He ight of R.C. Block Buildings (m) Min. seismic wall
Intensity 6
thickness (mm)
190
Intensity 7
Intensity 8
Intensity 9
0.05g
0.10g
0.15g
0.20g
0.30g
0.40g
60
55
45
40
30
24
Notes: 1 When the building height exceeds the height as provisions in the Table, the effective strengthened measures shall be taken based on special studies. 2 When the building area of room being greater than 6.0m among a certain or several storeys bays accounts for greater than 40% the corresponding storey building area, the data in the Table shall be reduced by 6m correspondingly; 3 Building height refers to the distance from outdoor ground to main roof slab top (excluding partial section being outside the roof).
Table F.1.1-2 Maximum Height-width Ratio of R .C. block buildings Intensity
6
7
8
9
Maximum height-width ration
4.5
4.0
3.0
2.0
Note: When the plane layout and vertical layout of a building is irregular, the maximum height-width ratio shall be reduced properly.
F.1.2
For R.C. block buildings, different seismic Grades shall be adopted based on precautionary
category, Intensity and the height of buildings, and shall also comply with the requirements of corresponding calculations and design details. The Grades of buildings assigned to Category C should be determined in accordance with the provisions in Table F.1.2. Table F.1.2 Seismic Grades of R.C. Block Buildings Intensity
6
7
8
9
Height (m)
≤24
>24
≤24
>24
≤24
>24
≤24
Seismic-Grade
Grade 4
Grade 3
Grade 3
Grade 2
Grade 2
Grade 1
Grade 1
184
Note: When the building height is close or equal to the height boundary, the seismic Grades may be adjusted in consideration of the irregular degree of the building, the site and the subsoil condition.
F.1.3
The R.C. block buildings shall avoid the irregular structures specified in Section 3.4 of this
code, and shall also meet the following requirements: 1
The plan shape should be simple, regular, and re-entrant corners should not be too significant;
the vertical arrangement should be regular, even, and the setback or overhang should not be too significant. 2
Each of longitudinal or transversal seismic wall should be aligned in-plan. The length of each
separate seismic wall should neither be greater than 8m nor 5 times of seismic wall thickness; the total height to width ratio of each seismic wall segment should not be less than 2; and the door openings should be in a line and should be arranged in rows. 3
When cast-in-situ reinforced concrete roof is adopted, the maximum spacing of the
transversal seismic wall in the building shall meet the requirements in Table F.1.3. Table F.1.3 Maximum Spacing of the Transversal Seismic w all Intensity
6
7
8
9
Maximum spacing (m)
15
15
1l
7
4 If seismic joints shall be arranged for a building, the minimum width shall meet the following requirements: When the building height is not greater than 24m, 100mm may be adopted ; when the height is greater than 24m, the width for Intensity 6, Intensity 7, Intensity 8 and Intensity 9 shall be widened by 20mm and the height shall be added by 6m, 5m, 4m and 3m respectively. F.1.4
1
Storey height of R.C. block building shall meet the following requirements: The storey height of bottom reinforced position should not be greater than 3.2m for Grade 1
and 2; it shall not be greater than 3.9m for Grade 3 and 4. 2
Storey height of other positions shall not be greater than 3.9m for Grade 1 and 2; and not be
greater than 4.8m for Grade 3 and 4. Note: bottom reinforced position refers to the floor not neither being less than 1/6 building height nor less than bottom secondary storey height and the building total height is less than 21m.
F.1.5
1
Short seismic wall of R.C. block building shall meet the following requirements: R.C. block seismic wall with all short seismic wall shall not be adopted, instead, short
seismic wall and general seismic wall shall be adopted together to resist horizontal earthquake action. For Intensity 9, short seismic wall should not be adopted. 2
Under specified horizontal force action, the bottom earthquake overturning moment bore by
seismic wall generally shall not be less than 50% total structural overturning moment; in addition, the ratio of short-seismic-seismic wall sectional area to the same-storey seismic wall total section area should not be greater than 20% in two major axis directions. 185
3
Wing seismic wall should be arranged for short seismic wall; floor and roof beams
intersecting with one side of the “—” shaped short seismic wall plane shall not be arranged outside the plane. 4
Seismic Grade of short seismic wall shall be adopted according to one Grade higher than that
of specified in Table F.1.2; when the seismic Grade of short s eismic wall is Grade 1, the reinforcement shall be improved according to Intensity 9 requirements. Note: short seismic wall refer to those seismic wall with their height-width ratios of seismic wall limbs being 5~8; general seismic wall refer to those seismic wall with their height-width ratios of seismic wall limbs being greater than 8. The properties of the long and short limbs of “L”-shaped, “T”-shaped and “+”-shaped multi-limb seismic wall sections shall be determined by the longer limb.
F.2 F.2.1
Essentials in Calculation
When seismic analysis is made for R.C. block buildings, the earthquake action effect shall be
adjusted according to the provisions of this code. Sectional seismic checking may not be carried out for Intensity 6, but details of seismic design shall be taken according to the relevant requirements in this Appendix. Seismic deformation checking under frequent earthquake actions shall be carried out for R.C. block building. As for the maximum elastic storey drift angle in a storey, it should not be greater than 1/1200 for bottom storey and not be greater than 1/800 for other storeys. F.2.2
For checking the seismic bearing capacity of R.C. block seismic wall, the combination shear
force design value of the cross section at the bottom-strengthened portion shall be determined in accordance with the following formula: V =ηvwV w Where,
V ——The
combination
shear
force
design
value
(F.2.2) of
the
cross
section
at
the
bottom-strengthened location; V w ——The combination shear force calculating value of the cross section at bottom-strengthened location; ηvw ——The shear force enhancement coefficient, taken as 1.6 for Grade 1, as 1.4 for Grade 2, as 1.2 for Grade 3, and as 1.0 for Grade 4. F.2.3
The combination shear force design value of cross section for the R.C. block seismic wall
shall meet the following requirements: When the shear-span ratio is larger than 2
V≤
1
(0.2 f bh)
(F.2.3-1)
(0.15 f bh)
(F.2.3-2)
γ RE
g
When the shear-span ratio is not larger than 2
V≤
1 γ RE
g
186
Where f g ——The design value of specified compressive strength of core-grouting small-block masonry; b ——Width of seismic wall cross section; h ——Height of seismic wall cross section; γRE ——Seismic adjusting factor for bearing capacity, may be taken as 0.85. Note: The shear-span ratio shall be calculated according to formula (6.2.9-3) of this code.
F.2.4
The shear bearing capacity of cross section for eccentric compressive R.C. block seismic wall
shall be checked in accordance with the following formulae:
V ≤
1 ⎡
1
γ RE ⎢⎣ λ − 0.5
(0.48 f
A sh
bh 0 +0.1 N ) + 0.72 f
gv
yh
0.5V ≤
s
⎤
h0 ⎥
⎦
1 ⎛ A sh ⎞ h 0 ⎟⎟ ⎜⎜ 0.72 f γ RE ⎝ yh s ⎠
(F.2.4-1)
(F.2.4-2)
Where N ——Combination axial force design value of the seismic wall, when N>0.2 f gbh, N=0.2 f gbh; λ ——Shear-span ratio at the calculation cross section, take as λ =M/Vh0, as 1.5 for the ratio less than 1.5, and as 2.2 for the ratio larger than 2.2; f gv ——The shear strength design value of core-grouting small-block masonry, take f gv=0.2 f gc0.55; Ash ——Cross-sectional area of horizontal reinforcement with the same cross section; s ——Spacing of horizontally distributed reinforcements; f yh ——Designed tensile strength value of horizontally distributed reinforcements; h0 ——Effective height of cross section of the seismic wall; F.2.5
In the combination of frequent earthquake action, the limbs of R.C. block seismic wall shall be
free from small eccentric tension. As for the great eccentric-tension R.C. block seismic wall, the shear bearing capacity of the diagonal section shall be calculated according to the following formula.
V ≤
1 ⎡
1
γ RE ⎢⎣ λ − 0.5
0.5V ≤
(0.48 f
bh 0 −0.17 N ) + 0.72 f
gv
yh
1 ⎛ A sh ⎞ h 0 ⎟⎟ ⎜⎜ 0.72 f γ RE ⎝ yh s ⎠
A sh s
⎤
h0 ⎥
⎦
(F.2.5—1)
(F.2.5—2)
When 0.48 f gvbh 0 −0.17 N ≤0, 0.48 f gvbh 0 −0.17 N =0 Where, N—— Axial-tension design value of seismic wall combination F.2.6
For the R.C. block seismic wall, the coupling beams with span-height ratio greater than 2.5
should adopt reinforced concrete coupling beam, which combination shear force design value and the 187
seismic shear bearing capacity shall meet the relevant requirements for coupling beam in the current national standard “Code for Design of Concrete Structures” GB 50010. F.2.7
When block masonry coupling beam is adopted for seismic wall, the following requirements
shall be met: 1 Coupling beam section shall meet the requirements of the following formula:
V≤
1 γ RE
(0.15 f bh ) g
(F.2.7—1)
0
2 Shear bearing capacity of coupling-beam diagonal section shall be calculated according to following formula:
V≤
A ⎞ 1 ⎛ ⎜⎜ 0.56 f gvbh 0 +0.7 f sv h 0 ⎟⎟ γ RE ⎝ yv s ⎠
(F.2.7—2)
Where, Asv —— The gross section area of each hoop limb being arranged in the same section; f yv —— Design value of hoop tensile strength
F.3 F.3.1
Details of Seismic Design
The grout concrete of R.C. block buildings shall adopt concrete with good slump, flowing and
workable properties, as well as good bonding characters with blocks. The strength Grade of grout concrete shall not be lower than Cb20. F.3.2
All seismic wall of R.C. block building shall be poured with grout concrete.
F.3.3
Transverse and vertical reinforcements of R.C. block seismic wall shall meet the requirements
in Table F.3.3-1 and F.3.3-2. The transverse reinforcements should be arranged in double rows; the tie-tendon interval hereof shall not be greater than 400mm and the diameter shall not be less than 6mm. The vertical reinforcement should be arranged in single row and the diameter shall not be greater than 25mm.
Table F.3.3-1: Requirements of Tranverse Reinforcement Structures of R.C. block Seismic wall Minimum reinforcement ratio (%) Seismic Grade
Reinforcement General position
Maximum space
Minimum diameter
(mm)
(mm)
position Grade 1
0.15
0.15
400
φ8
Grade 2
0.13
0.13
600
φ8
Grade 3
0.11
0.13
600
φ8
Grade 4
0.10
0.10
600
φ6
Note: For Intensity 9, reinforcement ratio shall not be less than 0.2%; at the top and bottom reinforcement position, the 188
maximum interval shall not be greater than 400mm.
Table F.3.3-2: Requirements of Vertical Reinforcement Structures of R.C. block Seismic wall Minimum reinforcement ratio (%) Seismic Grade
Reinforcement General position
Maximum space
Minimum diameter
(mm)
(mm)
position Grade 1
0.15
0.15
400
φ12
Grade 2
0.13
0.13
600
φ12
Grade 3
0.11
0.13
600
φ12
Grade 4
0.10
0.10
600
φ12
Note: For Intensity 9, reinforcement ratio shall not be less than 0.2%; at the top and bottom reinforcement position, the maximum interval shall be reduced properly.
F.3.4
The axial force ratio of R.C. block seismic wall under gravity-load representative value action
shall meet the following requirements: 1
As for the bottom reinforcement position of general seismic wall, the axial force ratio should
not be greater than 0.4 for Grade 1 (Intensity 9); not be greater than 0.5 for Grade 1 (Intensity 8); not be greater than 0.6 for Grade 2 and 3; and the ratio of general positions should not be greater than 0.6. 2
The axial force ratio of short seismic wall within its total height range should not be greater
than 0.50 for Grade 1 and not be greater than 0.60 for Grade 2 and 3; for “—”shaped short seismic wall without flange, the ratio limit shall be reduced by 0.1 correspondingly. 3
If seismic wall limb sections at all directions are independent small seismic wall limbs
(3b
Boundary structures shall be arranged at the end of R.C. block seismic wall; when the axial
force ratio at the bottom reinforcement position is greater than 0.2 for Grade 1 and 0.3 for Grade 2, restraining boundary structure shall be arranged. Reinforcement range of structural boundary components: 3-hole reinforcements for end without wing seismic wall and “L”-shaped intersection angle joint; 4 hole reinforcements for “T”-shaped intersection angle joint; horizontal hoop shall be arranged within boundary structure range and the minimum reinforcement shall meet the requirements in Table F.3.5. Within the range of restraining boundary structure, 1 hole shall be added along stressing direction basing on structural boundary component; horizontal hoops shall be correspondingly reinforced or concrete frame column may be adopted for reinforcement.
Table F.3.5: Reinforcement Requirements of Seismic wall Boundary Structures Minimum reinforcement amount of each-hole
Minimum diameter
vertical reinforcement
of horizontal hoop
Seismic Grade
Horizontal hoop
189
Bottom reinforced General position
Maximum space
position Grade 1
1φ20
1φ18
φ8
200mm
Grade 2
1φ18
1φ16
φ6
200mm
Grade 3
1φ16
1φ14
φ6
200mm
Grade 4
1φ14
1φ12
φ6
200mm
Note: 1 2
Boundary structure horizontal hoop should be lap point weld mesh type;
For Grade 1, 2 and 3, the boundary structural hoop shall be hot rolled reinforced bar not being less than Grade
HRB 335; 3
When Grade 2 axial force ratio is greater than 0.3, the minimum diameter of horizontal hoop at bottom
reinforcement shall not be less than 8mm.
F.3.6
The overlapping length of vertical and lateral reinforcements in R.C. block seismic wall shall
not be less than 48 times reinforcement diameter and the anchorage length shall not be less than 42 times reinforcement diameter. F.3.7
Lateral reinforcements of R.C. block seismic wall shall be arranged continuously along
seismic wall length and the anchorage at both ends shall meet the following provisions: 1
For Grade 1 and 2 seismic wall, lateral reinforcement may bend an 180 degree hook around
vertical main reinforcement and the straight length at hook end should not be less than 12 times reinforcement diameter; lateral reinforcement may also be bent into end grout concrete but the anchorage length shall neither be less than 30 times reinforcement diameter or les s than 250mm. 2
For Grade 3 and 4 seismic wall, lateral reinforcement may be bent into end grout concrete;
while the anchorage length shall neither be less than 25 times reinforcement diameter nor less than 200mm. F.3.8
In R.C. block seismic wall, masonry coupling beam may be adopted for the coupling beam
with its span-depth ratio less than 2.5; and the corresponding structures shall meet the following requirements: 1
As for coupling beam, the length of up and down longitudinal reinforcement anchored into
seismic wall shall not be less than 1.15 times anchorage length for Grade 1 and 2; not be less than 1.05 times anchorage length for Grade 3; not be less than anchorage length for Grade 4; what's more, all the anchored-into-seismic wall-lengths shall not be less than 600mm. 2
Hoops of coupling beams shall be arranged along full beam length; the hoop diameter shall
not be less than 10mm for Grade 1; not be less than 8mm for Grade 2, 3 and 4; and the hoop spacing shall not be not greater than 75mm for Grade 1; not greater than l00 mm for Grade 2 and not greater than 120mm for Grade 3. 3
As for top storey coupling beam within stretching into seismic wall longitudinal
reinforcement range, hoops with spacing not being greater than 200mm shall be arranged; in addition, the diameter shall be the same with coupling beam hoop one. 4
Within the range from 200mm below beam top to 200mm above beam bottom, waist 190
reinforcement shall be arranged additionally and the spacing shall not be greater than 200mm; the amount of waist reinforcement for each storey shall not be not less than 2 φ12 for Grade 1 and not be less than 2φ10 for Grade 2, 3 and 4; the length of waist reinforcement stretching into seismic wall shall neither be less than 30 times reinforcement diameter nor be less than 300mm. 5
Openings should not be made on the coupling beam of the R.C. block seismic wall, when
openings are necessary, they shall conform to the following requirements: 1)
The steel sleeves with outer diameter not greater than 200mm shall be embedded in 1/3
location of the beam depth in the span middle; 2)
The effective height above and below the opening shall neither be less than 1/3 of the
beam depth nor 200mm; 3)
The strengthened reinforcements shall be arranged near the openings, the shear bearing
capacity check shall be made for cross sections weakened by the opening. F.3.9
1
Ring-beam structures of R.C. block seismic wall shall meet the following requirements: For seismic wall, cast-in-situ reinforced-concrete ring-beams shall be arranged at both the
foundation and each floor elevation section; ring-beam width shall be the same with seismic wall thickness and the section height should not be less than 200mm. 2
Compression strength of ring-beam concrete shall neither be less than the strength of
corresponding small core-pouring block masonry nor less than C20. 3
Ring-beam longitudinal-reinforcement diameters shall neither be less than the diameter of
lateral reinforcement in seismic wall nor less than 4φ12; longitudinal reinforcement of foundation ring-beam shall not be less than 4φ12; hoop diameter of ring-beam and foundation ring-beam shall not be less than 8mm and the spacing shall not be greater than 200mm. When ring-beam height is greater than 300mm, waist reinforcement shall be arranged along ring-beam section height direction; the spacing shall not be greater than 200mm and the diameter shall not be less than 10mm. 4
Depth of ring-beam bottom embedded into small block hole at seismic wall top should not be
less than 30mm; in addition ring-beam top shall be rough surface. F.3.10
Cast-in-situ reinforced concrete slab shall be adopted for the floor, roof and high R.C. block
buildings as well as when the Intensity is 9; cast-in-situ reinforced concrete slab should also be adopted multistoried building; when the seismic Grade is Grade 4, assembling integral reinforced concrete roof may be adopted as well.
191
Appendix G
Seismic Design for Composite Steel Brace and Concrete
Frame Structures and Composite Steel Frame and Concrete Core Tube Structures G.1 G.1.1
Steel-brace Reinforced Concrete Frames
When the seismic precautionary Intensity is 6 ~ 8 and building height is greater than the
maximum applicable height of reinforced concrete frame structure specified in Article 6.1.1 of this code, steel-brace concrete frame may be adopted to be made into the structures of lateral resistant system. When seismic design is carried out according to the requirements in this Section, the applicable maximum height should not be greater than the average maximum applicable height of reinforced concrete frame structure and frame-seismic-seismic wall specified in Article 6.1.1 of this code. As for those buildings whose heights are greater than the maximum applicable height, special study and demonstration shall be made and effective reinforcement measures shall be taken. G.1.2
For steel-brace concrete frame building, different seismic Grades shall be adopted according
to precautionary type, Intensity and building height and corresponding calculation and structural measure requirements shall also be satisfied. The seismic Grade of steel brace frame for Category C building shall be improved by one Grade basing on for the framed structure specified in Article 8.1.3 and Article 6.1.2 of this code; while reinforced concrete frame shall meet the framed structure requirements stated in Article 6.1.2 of this code as well. G.1.3
1
Structural layout of steel-brace concrete frame shall meet the following requirements: Steel-brace frame shall be arranged simultaneously at two major axis direction of the
structure. 2
Steel brace should be arranged continuously up and down. When the steel brace can not be
arranged continuously due to building design scheme influence, the braces shall be arranged continuously at the adjoining spans. 3
Steel-brace should be cross one or zigzag one or “V”-shaped one; when single brace is
adopted, diagonals at two directions shall basically be arranged symmetrically. 4
Steel-brace arrangements in a plane shall avoid twisting effect; if there is no big opening
between steel braces, the length-width ratio of floor and roof should meet the seismic wall spacing requirements stated in Article 6.1.6 of this code; in addition, steel brace should be arrangement in staircase as well. 5
The earthquake overturning moment of bottom steel-brace frame distributed according to
rigidity shall be greater than 50% total earthquake overturning moment of the structure. G.1.4
1
Seismic calculation of steel-brace concrete frame shall meet the following requirements: Structural damping ratio shall not be greater than 0.045 or the structural damping ratio may
be converted into equivalent damping ratio according to concrete frame and steel-brace ratio accounting for total deformation. 192
2
Partial diagonals of steel-brace frame may be calculated according to end hinge bar. When the
deviation of brace diagonal axis from concrete column axis is greater than 1/4 column width, additional bending moment shall be considered. 3
Earthquake action bore by the concrete frame shall be calculated according to these two
models of framed structure and braced frame; in addition, the greater value shall be adopted. 4 Storey drift limit of steel-brace concrete frame should be interpolated according to frame and frame-seismic seismic wall. G.1.5
Connection structure of steel brace and concrete column shall meet the relevant requirements
on single-floor reinforced-column plant-building brace and brace connection specified in Section 9.1 of this code. Connection structure of steel brace and concrete beam shall meet the requirements that connection shall not be ahead of brace destroying. G.1.6
In steel-brace concrete frame structure, steel-brace part shall be designed according to the
provisions in current national standards, “Code for Design of Steel Structures” GB 50017 and Chapter 8 of this code; reinforced concrete frame shall be designed according to the provisions in Chapter 6 of this code. G.2 G.2.1
Steel-frame Reinforced-concrete Core Tube Structures
When the seismic precautionary Intensity is 6 ~ 8 and building height is greater than the
maximum applicable height of concrete-frame core tube structure specified in Article 6.1.1 of this code, steel-frame concrete core tube may be adopted to be made into the structures of lateral resistant system. When seismic design is carried out according to the requirements in this Section, the applicable maximum height should not be greater than the average value of maximum applicable height of reinforced-concrete frame core tube structure stated in Article 6.1.1 of this code and the one of steel-frame intermediate bracing structure stated in Article 8.1.1 of this code. As for those buildings whose heights are greater than the maximum applicable height, special study and demonstration shall be made and effective reinforcement measures shall be taken. G.2.2
Different seismic Grades shall be adopted for the steel-frame concrete core tube building
according to the precautionary type, Intensity and building height; in addition, the corresponding requirements of calculation and structural measures shall also be satisfied. For Category C building, the seismic Grade and steel frame part are still determined according to Article 8.1.3 of this code; the concrete part shall be improved by one Grade (when the Intensity is 8, the Grade shall be greater than Grade 1) basing on the one specified in Article 6.1.2 of this code. G.2.3
Structural layout of Steel-frame reinforced-concrete core tube building shall meet the
following requirements: 1
Connection of outside -steel frame beam and column for steel-frame core tube shall be rigid
connection; besides, steel beam should be adopted for floor beam. Profile steel for connection should be arranged in the position where concrete seismic wall body is connected with steel beam rigidly. 2
Maximum storey-earthquake-shear force distributed according to rigidity computation for
steel frame part should not be less than 10% total earthquake shear force of the structure. If it is less than 10%, earthquake action bore by core tube seismic wall shall be enlarged properly; the seismic Grade of seismic wall should be improved by one Grade and when the seismic Grade is still Grade 1, 193
the seismic Grade shall be improved properly. 3
The roof of steel-frame core tube structure shall be endowed with good rigidity and shall be
integral under rare earthquake action. Roof shall be profiled-steel-sheet combination one or cast-in-situ reinforced concrete slab; in addition, measures shall be taken to strengthen the connection between roof and steel beam. When there is major opening in a floor or the floor is transition storey surface, such measures as adopting cast-in-situ solid roof shall be taken. 4
When profile-steel concrete column is adopted at the bottom of steel frame column, transition
layer shall be arranged at the joints of frame columns made of different materials so as to avoid the sudden change of rigidity and bearing capacity. After transition-layer steel column is counted in envelope concrete, the sectional rigidity may be designed according to the average sectional rigidity of the section-steel concrete column at the bottom of transition layer and the steel column at the top of transition layer. G.2.4
Seismic calculation of steel-frame reinforced-concrete core tube structure shall meet the
following requirements: 1
Structural damping ratio shall not be greater than 0.045 or the structural damping ratio may
be converted into equivalent damping ratio according to reinforced concrete cylinder and steel frame ratio accounting for total deformation of the structure. 2
For steel frame, except partial extension-arm reinforcement storey and its adjacent one, the
earthquake shear force being distributed according to calculation of any storey shall be multiplied by enhancement coefficient so as to again the smaller value of the one not being less than 20% total earthquake shear force at structure bottom and the one being 1.5 times the maximum floor earthquake shear force of partial frame calculation; while the gained value shall not be less than 15% earthquake shear force at structure bottom. The calculated value of the shear force, bending moment and axial force of this floor frame due to earthquake action shall be adjusted correspondingly. 3
During structural calculation, the influence of axial deformation difference of steel frame
column and reinforced concrete seismic wall should be considered. 4 G.2.5
Reinforced concrete structure limit may be adopted as the structural storey drift limit. Steel structure and concrete structure in steel-frame reinforced-concrete core tube building
shall be designed according to the provisions in current national standard “Code for Design of Steel Structures” GB 50017, current relevant professional standards as well as Chapter 6 and Chapter 8 of this code.
194
Appendix H H.1
Seismic Design for Multi-storey Factory Buildings
Factory Buildings with Reinforced-concrete-frame Bent Structure
This chapter is applicable to the seismic design of lateral-frame bent structure factory building
H.1.1
being made by the lateral connection of reinforced concrete frame and bent frame as well as the seismic design of vertical-frame bent structure factory building with its bottom being reinforced concrete frame and its top being bent frame. If there is no provision in this Chapter, the seismic design shall be carried out according to relevant provisions in Chapter 6 and Section 9.1 of this code. For frames of frame-bent-structure factory building, different seismic Grades shall be adopted
H.1.2
according to the Intensity, structure type and height; in addition, corresponding calculation and structure measure requirements shall be met. When silo is not arranged, the seismic Grade may be determined according to Chapter 6 of this code; when silo is arranged, the seismic Grade of lateral frame-bent frame may be adopted according to the provisions specified in current national standard “Design Code for Anti-seismic of Special Structures” GB 50191 and the seismic Grade of vertical-bent-frame shall be 4m less than the height boundary specified in Chapter 6 of this code. Note: If silo is arranged for the frame but the span-depth ratio of vertical seismic wall is greater than 2.5, seismic Grade is still determined according to the frame without silo.
Structural layout of factory building shall meet the following requirements:
H.1.3
1
Factory building plane should be rectangular and its vertical face should be simple and
symmetrical. 2
Within structural unit plane, such lateral-force-resisting components as frames and column
brace should be arranged symmetrically and uniformly to avoid sudden change of the lateral rigidity and bearing capacity for lateral-force-resisting structure. 3
Equipment with great mass should not be arranged in the edge storey of structural unit, in
stead, it should be arranged in the position which is near rigidity center; if it is inevitable, equipment platform and major structures should be separated or low-level arrangement shall be adopted as far as possible when technological requirements are satisfied. Structural layout of vertical-frame-bent factory building shall meet the following
H.1.4
requirements: 1
Roof should be the one without purlin; when other roof system is adopted, roof brace and
connection between components shall be strengthened so as to ensure adequate horizontal rigidity of the roof. 2
At longitudinal end, roof truss, roof beam or framed structure instead of gable for bearing
shall be arranged; within bent span, cross seismic wall and bent shall not be adopted together for bearing. 3 Bent spans at top floor shall meet the following requirements: 1)
Bent gravity center should be approach to or superpose with the sub-structural rigidity
center; in addition, multi-span bent should be endowed with equal height; 195
2)
Roof shall be cast-in-situ; top-storey bent fixing floor shall be free from big opening
and the floor slab thickness should not be less than 150mm; 3)
Bent column shall stretch to the bottom continuously and vertically;
4)
At the longitudinal column brace of top bent, roof shall be free from any staircase or
opening; the center line of column brace diagonal rod shall meet with the center line of beam column at connection at one point. H.1.5
Earthquake action calculation of vertical-frame-bent factory building shall meet the following
requirements: 1
Space-filling model should be adopted for earthquake action calculation; mass point should
be arranged in the position of beam-column axis intersection point, corbel, column top, column variable cross section and concentrated load on column. 2
During the determination of gravity-load representative value, the variable load shall be the
corresponding combination coefficient of live load on a floor according to industrial characteristics. Load combination coefficient of silo storage may be 0.9. 3
When there is silo or equipment with high bracing gravity center in a storey, brace component
and its connection shall be taken into account of the additional bending moment generated by bunker, silo and equipment horizontal earthquake action. The just horizontal earthquake action may be calculated according to following formula:
F S = α max (1.0 + H X / H n )Geq
(H.1.5)
Where, F S —— Standard value of horizontal earthquake action at the gravity center of equipment or bunker;
α max —— Maximum value of horizontal seismic influence coefficient; Geq —— Gravity-load representative value of equipment or bunker; H X ——Distance from equipment or bunker gravity center to outdoor terrace; H n ——Factory building height H.1.6
Earthquake action effect adjustment and seismic checking of vertical-frame-bent factory
building shall meet the following provisions: 1
For the frame column of Grade 1, 2, 3 and 4 brace silo vertical seismic wall, the combination
bending-moment design value and shear-force design value adjusted according to Article 6.2.2, 6.2.3 and 6.2.5 of this code shall be multiplied by the enhancement coefficient; in addition, the enhancement coefficient shall not be less than 1.1. 2
The design value of bending moment combined at column end at the frame joint of top storey
where vertical-frame-bent structure is connected with bent column shall be adjusted according to 196
Article 6.2.2; while the designed bending moment at beam end and column end at other top storey frame joint may not be adjusted. 3
When longitudinal column brace is arranged for top bent, the additional axial force (caused
by earthquake) of the lower frame column of the bent column which is connected with column brace and the axial force (caused by earthquake) of Grade 1 and 2 frame column shall be multiplied by 1.5 and 1.2 (adjustment coefficient) respectively; when axial force ratio is calculated, the additional axial force may not be multiplied by adjustment coefficient. 4
Seismic check of frame-bent factory building shall meet the following requirements: 1)
For Category III and IV sites with Intensity 8 and for Intensity 9, bent column of frame
bent structure as well as the single column which outstretches the brace bent span roof of frame span roof shall be checked in aspects of plastoelastic deformation; in addition, the elastoplastic displacement angle limit may be 1/30. 2)
When the height difference of the beam sections on both sides of Grade 1 and 2 frame
beam column joint is greater than 25% the higher beam section height or 500mm, seismic shear bearing capacity of joint lower column shall be checked according to following formula:
η jb M b1 h01 − a s '
− V col ≤ V RE
(H.1.6-1)
When Intensity 9, the aforementioned formula may not be met, but shall meet:
1.15 M b1ua h01 − a s '
− V col ≤ V RE
(H.1.6-2)
Where, η jb —— Shear-force enhancement coefficient of a joint, 1.35 for Grade 1 and 1.2 for Grade 2;
M b1 —— Design value of combination bending moment at the bottom beam with higher end; M b1ua ——Bending moment corresponding to the seismic bending bearing capacity of the solidly arranged beam-bottom normal section at the end of higher beam, being determined according to solidly arranged reinforcement area (counted into compressive reinforcement) and material strength standard value;
h01 ——Effective height of the higher beam section; a s ' ——Distance from compressive reinforcement resultant force point to compression edge when the beam bottom at higher beam end is in tension;
V col ——Calculated-shear-force design value of joint lower column;
197
V RE ——Designed seismic shear-bearing-capacity of joint lower column Basic details of seismic design of vertical-frame-bent factory building shall meet the
H.1.7
following requirements: 1
Axial force ratio of the frame column bracing silo should not be by over 0.05 less than the
one specified in Table 6.3.6 of this code for framed s tructures. 2
Minimum total reinforcement ratio of the longitudinal reinforcement bracing silo frame
column shall not be less than the one required for corner column and listed in Table 6.3.7 of this code. 3
When longitudinal column brace is arranged for the top bent of vertical-frame-bent structure;
the lower frame column of bent column which is connected with column brace, longitudinal reinforcement ratio and hoop arrangement shall meet the requirements specified for frame-brace column in Article 6.3.7 of this code; in addition, total column height is in hoop densified area. 4
When the shear span ratio of frame column is not greater than 1.5, the following requirements
shall be met: 1)
Hoop shall be arranged according the Grade being improved by one; when the Grade is
still Grade 1, requirements for hoop shall be improved properly; 2)
Two diagonal reinforcements (Figure H.1.7) shall be arranged at each direction of frame
column and the diagonal diameter shall not be less than 20mm and 18mm for Grade 1 and Grade 2 frames; the diameter or Grade 3 and Grade 4 frame shall not be less than 16mm; besides, the anchorage length of diagonal shall not be less than 40 times diagonal reinforcement diameter.
h— Clear height of short column; l a — Anchorage length of diagonal reinforcement Figure H.1.7 5
When corbels are arranged in frame column segment, frame column hoops for corbels and
within 500mm up and down shall be densified; when the ratio of corbel up-and-down column clear height to column section height is greater than 4, column hoops shall be densified in the whole height range. H.1.8
Structural layout, earthquake action effect adjustment and seismic checking of lateral frame
bent structure as well as the brace arrangement of roof with/without purlin shall meet the relevant provisions stated in current national standard “Design Code for Antiseismic of Special Structures” GB 50191.
198
H.2 H.2.1
Multi-storey Steel Factory Buildings
This Section is applicable to such structures as the steel frames, brace frames and frame bents
of multi-storey factory buildings. If it is not specified in this Section, the relevant seismic requirements of multi-storey may meet those specified in Chapter 8 of this code and the seismic Grade height boundary shall be reduced by 10m basing on the one stated in Section 8.1 of this code; the seismic requirements of single-storey may meet those specified in Section 9.2 of this code. H.2.2
In addition to those requirements stated in Chapter 8 of this code, the arrangement of
multi-storey steel factory building shall meet the following requirements as well: 1
If the plan form is complex; each structure height differs greatly from each other or storey
load differs greatly, seismic joints shall be arranged or other measures shall be taken. If seismic joints are arranged, the joint width shall not be less than 1.5 times the corresponding concrete building. 2
Heavy equipments should be arranged at low level.
3
When equipment weight is directly bore by its foundation and the equipment shall go through
storey vertically, factory building storey shall be separated with the equipment. Width of joint between equipment and storey shall not be less than seismic joint width. 4
Equipment shall not be arranged across seismic joints on a storey; when such long
installations as transporter and pipeline have to go through seismic joint for arrangement, those equipments shall be endowed with adaptability to structural distortion during an earthquake or measures to prevent fracture shall be taken. 5
Working platform structures in factory building and frame structures of factory building
should be arranged away from seismic joints. When building structures are connected into integrity, elevation of platform structures should be consistent with the corresponding storey elevation of factory building frames. H.2.3
Support arrangements of multi-storey steel structural factory building shall meet the following
requirements: 1
Column brace should be arranged between columns with major loads and the column brace
shall go through up and down the same column. If the support must be arranged in stagger due to a certain condition, such arrangement shall be carried out continuously between the adjacent columns; in addition, the horizontal brace of close storey or roof should be added properly or one storey of column brace shall be overlapped to ensure the horizontal earthquake action undertook by the brace to transfer to the foundation reliably. 2
For structures with removing column, horizontal brace for close storeys and roofs shall be
added properly; in addition, vertical support shall be arranged between adjacent columns. 3
If the lateral rigidities of all frames differ greatly from each other and the column brace
arrangement is irregular; roof horizontal brace shall be arranged for those roof with steel slabs. 4 H.2.4
Longitudinal rigidities of all columns should be equal to or close to each other. Factory building roof should be in-situ-concrete composite slab or assembling integral slab or
steel one; in addition, the following requirements shall be met: 1
Concrete roof shall reliably be connected with steel beam. 199
2
When there are openings in floor slab, reliable measures shall be taken to ensure floor slab to
transfer earthquake action. H.2.5
Complete roof brace shall be arranged for frame-bent structure and shall meet the following
requirements: 1
The connection support elevation of bent roof cross beam and multi-storey frame should be
consistent with the corresponding storey one of multi-storey frame; in addition, horizontal support in the longitudinal direction of the roof shall be arranged along the full length of single-storey and multi-storey connection colonnades. 2
High spans and low spans should be made into relatively independent and closed brace
systems according to their own elevations respectively. H.2.6
Earthquake action calculation of multi-storey steel structural factory building shall meet the
following requirements: 1
Generally, space-filling model should be adopted for analysis; when the structural layout is
regular and the mass distribution is uniform, checking may also be carried out along both the transverse and longitudinal directions of the structure respectively. For cast-in-situ reinforced concrete slab, when slab opening is relatively small and shear connection component is used and connected into an integrity with steel beam, such concrete slab may be regarded as rigid floor. 2
If earthquakes are frequent, structural damping ratio may be 0.03 ~ 0.04; if the earthquake is
rare, the damping ratio may be 0.05. 3
When the representative value of gravity load is determined, corresponding combination
value coefficients of repair loads and finished products on a floor (or floor loads due to raw materials piling) as well as the materials in equipment, bunker and pipe shall be adopted corresponding according to the industrial characteristics of variable loads. 4
Components of direct brace equipment and bunker as well as their connections shall be
counted into the earthquake action generated by equipments etc. Horizontal earthquake action to the brace components and their connections due to general equipments may be calculated according to the requirements stated in Article H.1.5 of this Appendix; the bending moment and torsion moment of supporting components due to such horizontal earthquake action may be calculated basing on the distance from equipment gravity center to brace component centroid. H.2.7
The seismic bearing capacity checking of multi-storey steel-structural factory building
components and joints shall meet the following requirements: 1
When the whole plastic bearing capacities on joint right and left as well as at column top and
bottom ends are checked according to formula (8.2.5) of this code, the strong column coefficient of frame columns for Grade 1 and during earthquake action control is 1.25; it is 1.20 for Grade 2 and during 1.5 times earthquake action control; and it is 1.10 for Grade 3 and during 2 times earthquake action control. 2
Under the following conditions, requirements in formula (8.2.5) of this code may not be met: 1)
Column top of single-storey frame or column top of multi-storey-frame top storey;
2)
Total shear bearing capacities of those frame columns not meeting the requirements in
formula (8.2.5) of this code along checking direction are less than 20% shear bearing capacity of this 200
storey frame; and the total shear bearing capacity of the frame columns in each storey colonnade not meeting the requirements of formula (8.2.5) is less than 33% total shear bearing capacity of all frame columns in this columniation, 3
The ratio of the designed internal stress of column brace component to its designed bearing
capacity should not be greater than 0.8; when column brace bears not less than 70% storey shear, the ratio should not be greater than 0.65. H.2.8
Basically seismic structural measures of multi-storey steel structural factory building shall
meet the following requirements: 1
Slenderness ratio of frame column should not be greater than 150; when axial force ratio is
greater than 0.2, the slenderness ratio should not be greater than 125 (1-0.8 N / Af ) 235 / f y . 2
The width-to-thickness ratio of frame column and beam plate piece shall meet the following
requirements: 1)
For single-storey part and multi-storey part, the total height of which is not greater than
40m, the ratio may meet the requirements in Section 9.2 of this code. 2)
When the total height of multi-storey part is greater than 40m, the ratio may meet the
requirements in Section 8.3 of this code. 3
In the maximum stress area of frame beam and column, flange section shall not be changed
suddenly and lateral brace shall be arranged for both upper and lower flanges; the distance from this bracing point and the adjacent bracing point shall meet the relevant requirements on plastic design stated in current standard “Code for Design of Steel Structures” GB 50017. 4
Column bracing components should meet the following requirements: 1)
The column brace of multi-storey frame should be formed into an “X” shape with frame
cross beam or into other shape being in favor of earthquake resistance; in addition, the slenderness ratio should not be greater than 150; 2)
The width-to-thickness ratio of brace bar plate piece shall meet the requirements stated
in Section 9.2 of this code. 5
When high-strength-bolt friction splicing is adopted for frame beam, the position of such
frame beam should be away from maximum stress area (the greater value of 1/10 beam clear span and 1.5 times beam depth). During beam flange splicing, high strength bolts being parallel to internal stress should be at least 3 rows and the sectional modulus of splice plate shall be greater than 1.1 times of the spliced sectional modulus. 6
Factory-building column bases shall ensure the bearing capacity of transmission column;
embedded, inserted or epibolic column bases should be adopted and those column bases shall be arranged according to the provisions in Section 9.2 of this code.
201
Appendix J
Adjustment on Seismic Effects for the Transversal Bent of Single-storey Factory J.1
J.1.1
Adjustment of Fundamental Natural Period
When the horizontal earthquake action of the factory is calculated by planar bent, the
fundamental natural period of the bent shall be adjusted to consider the some fixing-effect of the connection between the longitudinal seismic wall and the roof truss with the column. And this adjustment may be made according to the following provisions: 1
For bent consisting of reinforcement concrete truss or steel truss and reinforced concrete
columns, when there is longitudinal seismic wall, the natural period may be taken as 80% of the computed value of the period; and taken as 90% of the computed value when there is no longitudinal seismic wall; 2
For bent consisting of reinforcement concrete truss or steel truss and brick columns, the
natural period may be taken as 90% of the computed period value; 3
For bent consisted of wooden truss, steel-wood composed truss or light steel truss and the
brick columns, the natural period may be taken as the computed period value. J.2 J.2.1
Adjustment Coefficients of Bent Column Seismic Shear and Bending Moment
The of single-storey reinforced concrete column factory with reinforced concrete roof, when
satisfying the following requirements, may take the space work and torsion effect into consideration. Thereinto, the seismic shear and bending moment of column for plain bent, that the fundamental natural period determined by Article J.1.1, shall be adjusted according to the provisions in Article J.2.3: 1
For Intensity 7 or 8;
2
The ratio of the roof length to the total span for the factory building unit is less than 8, or the
total span of the factory building unit is larger than 12m; 3
The thickness of the gable seismic wall is not less than 240mm, the horizontal sectional area
of the opening does not exceed 50% of the gross sectional area of gable seismic wall, and is reliable connected with the roof system; 4
The height of the top of column is not larger than 15m.
Note: 1 The roof length refers to the spacing from the gable to the other gable; when there is only one gable, the distance from the gable to the bent that is considered; 2 For factory buildings with unequal height span where the difference between higher and the lower vary significantly, the total span may not include the lower span.
J.2.2
For the single-storey brick column factories with reinforced concrete roof or wooden roof in
full sheathing, which satisfying the following requirements, the space work may be taken into considerations. In which, the seismic shear force and bending moment of column for planar bent, that the fundamental natural period determined by Article J.1.1, shall be adjusted according to the provisions in Article J.2.3: 202
1
For Intensity 7 or 8;
2
There are load-bearing gables at the both end of factory building;
3
The thickness of the gable seismic wall or load-bearing transversal seismic wall is not less
than 240mm, the horizontal sectional area of the opening does not exceed 50% of the gross sectional area, and is reliably connected with the roof system; 4
The length of the gable or the load-bearing transversal seismic wall should not be less than
their heights; 5
The ratio of the roof length to the total span for the factory building unit is less than 8, or the
total span of the factory building unit is larger than 12m. Note: The roof length refers to the distance from the gable to the other gable (or the load-bearing transversal seismic wall).
J.2.3
The shear and bending moment of the bent column shall be multiplied with correspondent
adjusting factors respectively. For reinforced concrete columns, except the upper column at the intersecting point of the high and low span, the values may be adopted according to Table J.2.3-1; for brick columns with gables at the both ends, the values may be adopted according to Table J.2.3-2.
Table J.2.3-1 Adjusting Factors of Reinforced concrete Column Considering Space Word and Torsion Effect (Except the Upper Column at the Intersection Portion of High and Low Span) Roof Length(m) Roof Type
Gable ≤30
36
42
48
54
60
66
72
78
84
90
96
Equal height
-
-
0.75
0.75
0.75
0.80
0.80
0.80
0.85
0.85
0.85
0.90
Unequal height
-
-
0.85
0.85
0.85
0.90
0.90
0.90
0.95
0.95
0.95
1.00
1.05
1.15
1.20
1.25
1.30
1.30
1.30
1.30
1.35
1.35
1.35
1.35
Equal height
-
-
0.80
0.85
0.90
0.95
0.95
1.00
1.00
1.05
1.05
1.10
Unequal height
-
-
0.85
0.90
0.95
1.00
1.00
1.05
1.05
1.10
1.10
1.15
1.00
1.05
1.10
1.10
1.15
1.15
1.15
1.20
1.20
1.20
1.25
1.25
Both gables Without purlin
Only one end gable
With
Both gables
purlin
Only one end gable
Table J.2.3-2 Adjusting Factors Considering Space Effect for Brick Column Distance between gable or load-bearing transverse seismic wall(m) Roof Type
R.C. roof without purlin
≤12
18
24
30
36
42
48
54
60
66
72
0.60
0.65
0.70
0.75
0.80
0.85
0.85
0.90
0.95
0.95
1.00
203
R. C. roof with purlin or wooden roof 0.65
0.70
0.75
0.80
0.90
0.95
0.95
1.00
1.05
1.05
1.10
with full sheathing
J.2.4
The seismic shear and bending moment determined by the base shear method for all the
sections of the reinforced concrete column above the bracket, braced the low span roof at the intersection of the high and low span of the factory, shall be multiplied by the enhancement coefficient. Such values may be adopted according to the following formula:
η=ζ (1+1.7
nh G El
⋅
n0 G Eh
)
(J.2.4)
Where η ——The seismic shear and the bending moment enhancement coefficient; ζ ——The space influence factor at the intersection of high and low span in factory buildings with unequal height, that may be taken in accordance with Table J.2.4; nh ——Number of spans for the higher span; n0 ——Number of span for computation; if only one side has low span, that shall be taken as the total number of span; if there are low spans on the two sides, shall be taken as the sum of the total number of span and the number of high span; GEL ——Total gravity load representative value, which concentrating at the roof level of all the low spans on one side of the intersection; GEh ——Total gravitational load representative value, which concentrating at the level of column top of the entire high spans.
Table J.2.4 Space Influence Factor of Reinforced Concrete Upper Column at the Intersection of the High and Low Spans Roof length (m) Roof Type
Gable
Without
Both gables
purlin
Only one end gable Both gables
≤36
42
48
54
60
66
72
78
84
90
96
-
0.70
0.76
0.82
0.88
0.94
1.00
1.06
1.06
1.06
1.06
1.15
1.15
1.15
1.20
1.20
1.25 -
0.90
1.00
1.05
1.10
1.10
With purlin Only one end gable
J.2.5
1.05
For the upper column section at the level of top of the crane beam in reinforced concrete
single-storey factory building, the seismic shear and the bending moment caused by the bridge crane shall be multiplied with the enhancement coefficient. For that determined by the base shear method, such values may be adopted according to Table J.2.5.
Table J.2.5 Enhancement coefficient of Seismic Shear and Bending Moment Caused by Portal Frame
204
Type of roof
Gable
Side column
Column of high and low spans
Other mid-columns
Both gables
2.0
2.5
3.0
Only one end gable
1.5
2.0
2.5
Both gables
1.5
2.0
2.5
Only one end gable
1.5
2.0
2.0
Without purlin
With purlin
205
Appendix K
Seismic Check for Single-storey Factory in Longitudinal Direction
K.1
Modification Rigidity Method for Longitudinal Seismic Calculation of Factory Buildings with Single-storey Reinforced Concrete Columns
K.1.1
Calculation on longitudinal fundamentally natural period:
During the longitudinal earthquake action of
the single span and multi-span (with equal height)
reinforced concrete column factory buildings is calculated and when the elevation of column top is not larger than 15m and the average span is not larger than 30m, the longitudinal fundamental period may be determined according to the following formulae: 1
The fundamental natural period of such factory with brick enclosure seismic wall may be
obtained according to the following formula: 3
T 1=0.23+0.00025ψ 1l H
(K.1.1-1)
Where ψ 1 ——The roof type factor; for reinforced concrete truss with large-sized roof slab, that may be taken as 1.0; and for steel truss taken as 0.85; l ——Span of the factory building (m); for multi-span factory building, the average value for all spans may be adopted; H ——Height from foundation top to column top (m) 2
The fundamental natural period of factory buildings, which is no enclosure seismic wall, half
no seismic wall or that the seismic wall panels are flexibly connected with columns, may be calculated according to formula (K.1.1-1) in this Article, and then multiply by the enclosure seismic wall influence factor below: 3
ψ 2=2.6-0.002l H
(K.1.1-2)
Where ψ 2 ——The factor of the enclosure seismic wall influence; if it is less than 1.0, shall equal 1.0. K.1.2
1
The calculation for the seismic action of colonnade: For factory buildings with equal height and multi-span reinforced concrete roof, the seismic
action standard value at the top level of all longitudinal colonnades may be determined according to the following formulae:
F i=α1Geq
K ai
Σ K ai
K ai=ψ 3ψ 4 K i
(K.1.2-1)
(K.1.2-2)
Where F ——The longitudinal seismic action standard value at the top level of i-th colonnade; i α1 ——The horizontal seismic influence coefficient, which corresponding to the longitudinal 206
fundamental natural period of the factory building, shall be determined according to Article 5.1.5 of this code: Geq ——The representative value of total equivalent gravity load of unit colonnade for factory building unit. It shall include such as the roof gravity load representative value that determined according to Article 5.1.3 of this code, 70% of the weight of the longitudinal seismic wall, 50% of the weight of the transversal seismic wall and the gable, and the converted weight of the column. (The converted weight of column adopts 10% of the column weight when the factory there is crane, and 50% of the column weight when there is no crane); K ——Total lateral displacement rigidity of i-th colonnade. It shall be taken as the total sum of i the lateral displacement rigidity of the all of columns in i-th row, the column brace between the upper and lower column, and the reduced lateral displacement rigidity of the longitudinal seismic wall. The reduced factor for the lateral displacement rigidity of the brick enclosure seismic wall may be taken as 0.2 to 0.6 based on the lateral displacement value of the colonnade; K a ——Adjusting lateral displacement rigidity at the top of i-th colonnade; i ψ 3 ——The enclosure seismic wall influence factor of the lateral displacement rigidity of colonnade, which may be adopted according to Table K.1.2-1; for four-span and five-span factory buildings with longitudinal brick enclosure seismic wall, the factor of 3rd colonnade counted from the side colonnade may be adopted according to 1.1 5 times of the corresponding values in this Table; ψ 4 ——The column brace influence factor for lateral displacement rigidity of colonnade; when the longitudinal seismic wall is of brick enclosure seismic wall, the factor of side colonnade may be taken as 1.0, and the mid-colonnade may be taken as per set in Table K.1-2-2.
Table K.1.2-1 Enclosure Se ismic wall Influence Factors
Type of colonnade and roof
Type of enclosure seismic wall and Intensity
Mid-colonnade Roof without purlin
240mm brick 370mm brick seismic wall
Roof with purlin
Side-colonnade
seismic wall
Side span without
Side span with
skylight
skylight
Side span without skylight
Side span with skylight
Intensity 7
0.85
1.7
1.8
1.8
1.9
Intensity 7
Intensity 8
0.85
1.5
1.6
1.6
1.7
Intensity 8
Intensity 9
0.85
1.3
1.4
1.4
1.5
0.85
1.2
1.3
1.3
1.4
0.90
1.1
1.1
1.2
1.2
Intensity 9 No seismic wall, asbestos sheet, or seismic wall panel
Table K.1.2-2 Brace Influence Factor of Mid-colonnade for the Longitudinal Brick Enclosure Seismic wall
207
Slenderness ratio of mid-colonnade lower column brace
Number of bay with lower column brace
One bay
Mid-colonnade without
≤40
41~80
81~120
121~150
>150
0.9
0.95
1.0
1.1
1.25
brace
1.40 Two bays
2
-
-
0.9
0.95
1.1
For factory buildings with equal height and multi-span reinforced concrete roof, the
longitudinal seismic action standard value at the level of top of the crane beam of colonnades may be determined according to the following formula:
F ci=α1Gci
H ci H i
(K.1.2-3)
Where F c ——The longitudinal earthquake action standard value at the level of top of crane beam of i i-th colonnade; Gci ——The equivalent gravity load representative value concentrating at the level of top of crane beam of i-th colonnade. It shall be taken as the sum of the gravity load representative values of the crane beam and the suspended object, which determined according to Article 5.1.3 of this code, and 40% of the weight of the column; H c ——Height of the top of crane beam for i-th colonnade; i H ——Height of the top for i-th colonnade. i K.2
Effect and Check on the column brace earthquake action of Factory Buildings with Single-storey Reinforced Concrete Columns
K.2.1
The horizontal displacement of column brace under the unit lateral force, that slenderness
ratio is not larger than 200, may be determined according to the following formula:
u=∑
1 1 + ϕ i
uti
(K.2.1)
Where u ——Displacement of unit lateral force application point; φ1 ——Diagonal axial compression stability coefficient of the i-th segment of column brace, that shall be determined according to the provisions of current national standard “Code for Design of Steel Structures” GB 50017; uti ——Relative displacement of the i-th segment of column brace under the unit lateral force when only the stress of tensile bar is taken into consideration. K.2.2
Diagonal cross section with slenderness ratio not larger than 200 may only be checked for the
tensile capacity, but the unloading effect of the compressive bar shall be taken into consideration, the tensile force may be determined according to the following formula:
N t=
l i (1 + ϕ cϕ i ) sc
V bi
(K.2.2)
208
Where N ——Axial tensile force design value of the diagonal tie of i-th segment of column brace for t tensile capacity check; l ——The total length of the i-th segment diagonal of column brace; i ψ c ——Unloading factor of the compressive bar; when the slenderness ratios of the compressive bar are separately 60, 100 and 200, such factor may be taken as 0.7, 0.6 and 0.5 accordingly; V bi ——The seismic shear design value of i-th segment of column brace; sc ——Net distance of the column brace. K.2.3
For the longitudinal colonnade without the close masonry seismic wall, the brace of the upper
column and lower column should be designed with uniform strength. K.3
Sectional Seismic Check for Embedded Parts at the End Joint of Column Brace in Factory Buildings with Single-storey Reinforced Concrete Columns
K.3.1
When the anchoring bars are taken as the anchor of embedded parts connecting the column
brace with the column, its sectional bearing capacity should be determined according to the following formulae:
N ≤
0.8 f y A s cosθ sin θ 0.8ξ mψ
ψ =
1+
+
(K.3.1-1)
ξ r ξ v
1 0.6e0
(K.3.1-2)
ξ r s
ζ m=0.6+0.25t /d
(K.3.1-3)
ζ v = (4 − 0.08d ) f c/ f y
(K.3.1-4)
Where A ——The total sectional area of the anchoring bars; s γRE ——The seismic adjusting factor of the bearing capacity, and it may be taken as 1.0; N ——Inclining tensile force of the embedded part, and it may adopt 1.05 times of the brace diagonal axial force, which calculated according to the yielding strength of the whole cross section of diagonal; e0 ——Eccentricity of the inclining tensile force to the application line of the resultant action of anchoring bar (ram); and it shall be less than 20% of the distance between the both of anchoring bars of the outer-row; θ ——The angel between the inclining tensile force and its horizontal projection; ψ ——The eccentricity influence factor; s ——Distance between both of outer-row anchoring bars (mm); ζ m ——Flexural deformation influence factor of embedded part; 209
t ——Thickness of embedded part (mm); d ——Diameter of anchoring bar (mm); ζ ——influence factor of the number of anchoring bar rows along the checking direction; for row r 2, 3 and 4, the factor may be taken as 1.0, 0.9 and 0.85 separately; ζ v ——Shear influence factor of the anchoring bar, it shall be taken as 0.7 when greater than 0.7. K.3.2
When the angel steel added end plate is taken as the anchor of embedded part of joint for the
column brace and column, the seismic bearing capacity of its cross section should be determined according to the following formulae:
N ≤
0.7
⎛ cosθ sin θ ⎞ ⎟⎟ γ re ⎜⎜ + ψ N V u 0 ⎠ ⎝ u 0
(K.3.2-1)
V u0=3nζ r W minbf a f c
(K.3.2-2)
N u0=0.8nf a As
(K.3.2-3)
Where, n ——Number of angel steel; b ——With of angel steel leg; W min ——Angel steel minimum sectional modulus orthogonal to the shear direction; A ——Sectional area of one angel steel s f a ——Design value of tensile strength of angle steel. Appendix K.4
Modification Rigidity Method of Longitudinal Seismic Analysis for Single-storey Factory with Brick Columns
K.4.1
The provisions of this Appendix shall be applied to the longitudinal seismic check for
single-storey brick column factory building with the reinforced concrete roof (with or without purlin) and equal height and multi-spans. K.4.2
Longitudinal fundamental natural period of structures of single-storey brick column factory
building may be determined according to the following formula:
T 1=2ψ T
ΣG s Σ K s
(K.4.2)
Where ψ T ——Period modifying factor, and it may be adopted according to Table K.4.2; gravity load of the s-th colonnade. It shall include the gravity load of G ——Concentrating s half-span roof and gable in the left and right of the colonnade, as well as the converted gravity load concentrated at the top level of the column or the seismic wall. Thereinto, the gravity of seismic wall and column is conversed according to the principle of dynamic energy equivalence; K ——Lateral displacement rigidity of the s-th colonnade. s 210
Table K.4.2 Modification Factor of Longitudinal Fundamental natural period of Factory Buildings R.C. roof without purlin Type of roof
R.C. roof with purlin
Side span without
Side span without Side span with skylight
Side span with skylight skylight
skylight Factors
1.3
1.35
1.4
1.45
The total horizontal seismic action standard value in the longitudinal direction of
K.4.3
single-storey brick-column factory building shall be determined according to the following formula: F Ek =α1 Σ Gs
(K.4.3)
Where α1 ——Seismic influence coefficient corresponds to the longitudinal fundamental natural period T 1 of single-storey brick column factory building; converted gravity load representative value concentrated at the top level of the G ——The s seismic wall of the s-th colonnade; that converted according to the principle of base shear force equality. K.4.4
Horizontal earthquake action of the top of the s-th longitudinal colonnade of the factory
building may be determined according to the following formula:
F s=
K s
s
Σψ s K s
F EK
(K.4.4)
Where ψ ——Rigidity adjusting factor of colonnade considering to the horizontal deformation of the s roof, and it shall be adopted according to Table K.4.4 based on the type of the roof and the arrangement of longitudinal seismic wall in all of colonnades.
Table K.4.4 Rigidity Adjusting Factor of Colonnades longitudinal seismic wall of mid-colonnade is Arrangement of longitudinal seismic wall not less 4 bays
A11 brick columns without seismic wall
Type of roof 0.6
1.8
R. C. roof without purlin
0.65
1.9
R. C. roof with purlin
Side-columnade
Mid-colonnade
Side-colonnade
Mid-colonnade
0.95
1.1
0.9
1.6
0.95
1.1
0.9
1.2
0.7
1.4
0.75
1.5
A11 colonnades are brick seismic wall with buttress longitudinal seismic wall of mid-colonnade is Side-columns are brick
not less 4 bays
211
212
Appendix L
Simplified Calculation, General and Details for
Seismically-isolated Masonry Structures L.1 L.1.1
Simplified Calculation for Seismically-isolated Design
When the multi-storey masonry structures and structures with similar fundamental natural
period adopt
seismically-isolated design, the total horizontal earthquake action of the structures
above the seismically-isolated storey may be determined simply according to Formula (5.2.1-1) of this code, but the following provisions shall be observed: 1
The Horizontal seismic-reduced factor should be determined according to the following
formula, that dependent upon the fundamental natural period of the seismically-isolated structural system:
β = 1.2η 2 (T gm / T 1 ) γ
(L.1.1-1)
Where β ——Horizontal seismic-reduced factor; η2 ——Damping adjustment factor of seismic influence coefficient, it shall be determined according to Article 5.1.5 of this code based on the equivalent damping of the seismically-isolated storey; γ ——The damped exponential index of the curvilinear decrease segment of the seismic influence coefficient, it shall be determined according to Article 5.1.5 of this code based on the equivalent damping of the seismically-isolated storey; T gm ——The design characteristic period of seismically-isolated design for the masonry structure, it shall be determined according to Article 5.1.4 of this code based on the design earthquake group, but shall be taken as 0.4s when that is less than 0.4s; T 1 ——The fundamental natural period of the seismically-isolated system, it shall neither be larger than 2.0s nor 5 times of the design characteristic period. 2
For structures that have similar fundament period with masonry structure, the horizontal
seismic-reduced factor should be determined according to the following formula based on the fundamental natural period of the seismically-isolated structural system:
β = 1.2η 2 (T g / T 1 ) (T 0T g ) γ
0.9
(L.1.1-2)
Where T 0 ——Computed period of non-isolated structure, when it is less than the design characteristic period value, shall be taken as the design characteristic period value; T 1 ——The fundamental natural period of the seismically-isolated system; it shall not be larger than 5 times of the design characteristic period value; T g ——Characteristic period; other signs are the same as described above. 3 The fundamental natural period of the seismically-isolated masonry structures and structures with similar period may be determined according to the following formula: 213
T 1=2π G / K h g
(L.1.1-3)
Where T 1 ——The fundamental natural period of seismically-isolated structural system; G ——Gravity load representative value of structures above the seismically-isolated storey; K h ——Horizontal dynamic rigidity of the seismically-isolated storey, it may be determined according to the provisions in Article 12.2.4 of t his code; g ——Acceleration of gravity. L.1.2
For the masonry structures and structures with similar period of masonry structures, under
rare earthquake action the horizontal shear force of the seismically-isolated storey may be determined according to the following formula: V c= λsα1(ζ eq)G
(L.1.2)
Where, V c ——Horizontal shear force of the seismically-isolated storey under rare earthquake. L.1.3
For the masonry structures and structures with similar period of masonry structures, under
rare earthquakes, the horizontal displacement of centroid of the seismically-isolated storey may be determined according to the following formula: ue= λsα1(ζ eq)G/ K h
(L.1.3)
Where, λs ——Near-field factors. For building located within 5km of the causative fault, it shall be taken as 1.5; within 5~10km, taken as 1.25; α1(ζ eq)——The seismic influence coefficient value under rare earthquake, it may be determined according to Article 5.1.5 of this code based on the seismically-isolated storey design parameters; K h ——The horizontal equivalent rigidity of the seismically-isolated storey under rare earthquake, it shall be determined according to provisions in Article 12.2.4 of this code. L.1.4
If the plain arrangement of the seismically-isolated-support is rectangular or nearly
rectangular, but the mass center of the structure above the seismically-isolated storey and the rigidity center of the seismically-isolated storey are eccentric, the torsion-effect factor of the seismically-isolated-support may be determined as follows: 1 When the torsion of only one-way seismic action (Figure L.1.4) is considered, the torsion effect factor may be estimated according to the following formula: β i=1+12esi/(a2+b2)
(L.1.4-1)
Where, e ——Eccentricity of the mass center of the structure above the isolation storey and the rigidity center of the isolation storey, that perpendicular to the direction of earthquake act ion; s ——The distance from the i-th seismically-isolated-support to the rigidity center of the isolation i storey perpendicular to the direction of earthquake action; a, b——The length of two sides in plain of the seismically-isolated storey. For side support, its torsion-effect factor shall not be less than 1.15; when effective anti-torsion measures are taken for the seismically-isolated storey and the structures above it, or when the torsion period is less than 70% of the fundament period, the torsion-effect factor may be taken as 1.15. 214
2 When the torsion of both way earthquake actions are considered, the torsion-effect factor may be determined according to formula (L.1.4-1), but the eccentricity value ( e) hereof shall be replaced by the greater value between that calculated according to the following formula: i-th su
ort
Direction of earthquake action
FigureL.1.4
Torsion calculation
e= e x
2
+ (0.86e y ) 2
(L.1.4-2)
e= e y
2
+ (0.86e x ) 2
(L.1.4-3)
Where ex ——Eccentricity of earthquake action along the y-axial direction; ey ——Eccentricity of earthquake action along the x-axial direction. For side support, its torsion-effect factor should not be less than 1.2. L.1.5
When seismic check under vertical earthquake action for masonry structures is made
according to the provisions in Article 12.2.5 of this code, the normal-stress effect factors for the seismic shear strength of masonry should be determined according to the mean compression stress which is subtracted by the vertical earthquake action effect. L.1.6
For the longitudinal or transversal beams at the top of the seismically-isolated storey of the
masonry structure, the calculation may be carried out according to the single-span
simply supported
beam or the multi-span continuous beam bore the uniformly distributed load. The uniformly distributed load values may be determined according to the provisions for reinforced concrete spandrel beam in Article 7.2.5 of this code. When the midspan bending moment computed by continuous beam is less than 0.8 times of that computed by the single-span simply-supported beam, the reinforcement shall be arranged according to 0.8 times of that computed by the single-span simply-support beam. L.2 L.2.1
The Details for Seismically-isolated Masonry Structure
When the Horizontal seismic-reduced factor of masonry structure assigned to Category C is
not larger than 0.40 (0.38 when damper is arranged), the limit value of number of storeys, the total height and the height-width ratio may be adopted according to the provisions, which corresponding to one Intensity degree lower, in Section 7.1 of this code. L.2.2
Details of seismically-isolated storey of masonry structure shall meet the following
provisions: 215
1
When the seismically-isolated storey of multi-storey masonry building locates at the top of
the basement, the seismically-isolated support should not be placed on the masonry seismic wall directly, and the partial compressive capacity of the masonry seismic wall shall also be checked. 2
The details of the longitudinal and transversal beams at the top of the seismically-isolated
storey shall meet the requirements for reinforced concrete spandrel beam of brick buildings with bottom-frame, which as per set in Article 7.5.8 of this code. L.2.3
For building assigned to Category C, the seismic design details for the masonry structure
above the seismically-isolated storey shall meet the following requirements: 1
The minimum distance from a bearing exterior seismic wall end to the side of the door or
window opening, as well as the details requirements of cross section and reinforcement of the ring-beam, shall meet the relevant requirements in Section 7.1 and Sections 7.3 and 7.4 of this code. 2
The reinforced concrete columns for multi-storey brick buildings shall be arranged as follows:
when the horizontal seismic-reduced factor is greater than 0.40 (0.38 when damper is arranged), it shall still meet the requirements in Table 7.3.1 of this code. For Intensity 7 to 9, when the horizontal seismic-reduced factor is not greater than 0.40 (0.38 when damper is arranged), it shall meet the requirements in Table L.2.3-1; 3
The reinforced concrete core-columns for R.C. block buildings shall be installed as follows:
when the horizontal seismic-reduced factor is greater than 0.40 (0.38 when damper is arranged), it shall meet the requirements in Article 7.4.1 of this code. For Intensity 7 to 9, when the horizontal seismic-reduced factor is not greater than 0.40 (0.38 when damper is arranged), it shall meet the requirements of Table L.2.3-2. 4
For other details of seismic design of the upper structures: when the horizontal
seismic-reduced factor is greater than 0.40 (0.38 when damper is arranged), they shall still meet the requirements in Chapter 7 of this code. For Intensity 7~9, when the horizontal seismic-reduced factor is not greater than 0.40 (0.38 when damper is arranged), they shall meet the requirements of being one Intensity lower than the one stated in Chapter 7
Table L.2.3-1 Requirements for Column Arrangement of Seismically-isolated Brick Buildings Number of storeys in building Arrangemtent locations Int.7
Int.8
3, 4
2, 3
Int.9 Four corners of the staircase and
lift
well; seismic wall segment
Eavry other 12m or intersections of unit transversal seismic wall and exterior seismic wall
corresponding to up and down ends of 5
4
2
staircase inclined segment; four corners of the exterior seismic wall and the corresponding intersections;
Intersection of every other 3 bay transversal seismic wall and exterior seismic wall Intersections of every other bay transversal seismic
intersections of transverse seismic wall wall (axis) and exterior seismic wall; intersections of 6
5
3, 4
in split-level
position and exterior
gable and interior longitudinal seismic wall;
longitudinal seismic wall; both sides of intersections of exterior and interior seismic wall for larger openings; intersections of interior
four storeys and Intensity 9
216
seismic wall and exterior seismic wall of large rooms
Intersections of interior seismic wall (axis)
and
exterior seismic wall, partially smaller piers of the 7
6, 7
5
interior seismic wall; intersections of transversal seismic wall (axis) and interior longitudinal seismic wall
Table L.2.3-2 Requirements for Column Arrangement of Seismically-isolated R.C bloc k Buildings Number of storeys Arrangemtent locations
Number of
columns
Int. Int. Int. 7
8
9 Corner of exterior seismic wall, four corners of staircase, seismic wall segments corresponding to up and down ends of staircase inclined segement, intersection
3,4 2,3
of interior and exterior seismic wall in large rooms, every other 12m or intersections of the unit transversal seis mic wall and exterior longitudinal seismic wall Corner of exterior seismic wall, four corners of staircase, seismic wall segments corresponding to up and down ends of staircase inclined segments, intersection of
5
4
2
Corners of the exterior seismic wall, 3 holes shall be filled; intersection of interior and exterior seismic wall, 4 holes filled
interior and exterior seismic wall in large r ooms, intersection of the interior seismic wall and the gable, intersection of every other 3 bay transversal seismic wall (axis) and exterior longitudinal seismic wall Corner of exterior seismic wall, four corners of staircase, seismic wall segments Corners of the exterior seismic corresponding to up and down ends of staircase inclined segment, intersection of wall, 5 holes shall be filled; interior and exterior seismic wall in large rooms, intersection of the interior intersection of interior and exterior
6
5
3
seismic wall and the gable, intersection of every other bay transversal seismic seismic wall, 5 holes filled; 1 holes wall (axis) and exterior longitudinal seismic wall; for Intensity 8 and 9, filled at both sides of the opening intersection of exterior longitudinal seismic wall and transversal seismic wall respectively (axis), both sides of bigger openings Corners of the exterior Corner of exterior seismic wall, four corners of staircase, seismic wall segments corresponding to up and down ends of staircase inclined segment, intersection of
7
6
4
all interior/exterior (axis) and exterior seismic wall; intersection of interior longitudinal seismic wall and transversal seismic wall (axis), both sides at 1:3 opening
seismic wall, 7 holes shall be filled; intersection of interior and exterior seismic wall, 4 holes filled; intersection of interior seismic wall, 4 or 5 holes filled; both sides of opening,1 hole
217
Appendix M
Objectives and Procedures of Performance-based Seismic Design
M.1
M.1.1
Seismic Performance Design Procedures for Structural Components
Seismic bearing capacity, deformability and constructional seismic Grade required for
seismic performance may be realized for structural component according to the following provisions; the same or different seismic performance requirements may be selected for the components, vertical components and horizontal components in different parts of the entire structure. 1
If it is mainly aimed at improving seismic safety, the bearing-capacity reference indexes of
structural components corresponding to different performance requirements may be adopted according to the samples listed in Table M.1.1-1.
Table M.1.1-1 Bearing-capacity Reference Indexes of Structural Components to Meet Seismic Performance Requirements Performance Frequent earthquakes
Precautionary earthquake
Rare earthquake
requirement Good, bearing capacity is rechecked Basically good, bearing capacity is rechecked according to design value when seismic Performance 1 Good, being generally designed
according to the design value when seismic Grade adjusting earthquake effect is Grade adjusting earthquake effect is not counted counted Basically good, bearing capacity is rechecked according to the design value Light to moderate damage, bearing capacity is
Performance 2 good, being generally designed when seismic Grade adjusting earthquake
rechecked according to limit value
effect is not counted Moderate damage, when bearing capacity Light damage, bearing capacity is Performance 3 Good, being generally designed
reaches the limit it can maintain stable and the rechecked according to criterion value reduction is less than 5% light to moderate damage, bearing
Not severe damage, when bearing capacity
Performance 4 Good, being generally designed capacity is rechecked according to limit reaches the limit it can basically maintain stable value
2
and the reduction is less than 10%
When the service performance is determined according to earthquake residual deformation, the
structural component shall meet the requirements of improving seismic safety performance; in addition, the storey drift reference indexes with different performance requirements may be adopted according to Table M.1.1-2.
Table M.1.1-2: Storey Drift Reference Indexes of Structural Components to Meet Seismic Performance Requirements
218
Performance Frequent earthquakes
Precautionary earthquake
Rare earthquake
requirement Good, the deformation is much less Good, the deformation is less than elastic Basically good, the deformation is a little Performance 1 than elastic displacement limit
displacement limit
greater than elastic displacement limit Slight plastic deformation, the deformation
good, the deformation is much less Basically good, the deformation is a little Performance 2
is less than 2 times elastic displacement than elastic displacement limit
greater than elastic displacement limit limit Obvious plastic deformation, the
Good, the deformation is obviously
Slight damage, the deformation is less
less than elastic displacement limit
than 2 times elastic displacement limit
Performance 3
deformation is about 4 times elastic displacement limit Slight to moderate damage, the
Not severe damage, deformation is not
deformation is less than 3 times elastic
greater than 0.9 times plastic deformation
displacement limit
limit
Good, the deformation is less than Performance 4 elastic displacement limit
Note: during the deformation calculation under precautionary Intensity and rare earthquake, gravity second-order effect shall be considered and integrally flexural deformation may be deducted.
3
Seismic
Grades
with
different
performance
requirements
corresponding
to
structural-component detailed structures may be adopted according to the samples listed in Table M.1.1-3; for the different components of the same structure in different parts, these components may be divided into vertical components and horizontal components then the seismic structural Grades are adopted according to the corresponding minimal performance requirements.
Table M.1.1-3: Samples of Structural Seismic Grades with Different Performance Requirements Corresponding to Structural Components Performance Seismic Grades of structures requirements For basic seismic structure, the seismic Grades may be adopted according to 2 intensities less than the relevant provisions Performance 1 for conventional design, but not less than Intensity 6 and being free from brittle failure For structure with low tensibility, the seismic Grades may be adopted according to one Intensity less than the relevant provisions for conventional design; when the bearing capacity of a component is greater than the requirements that two Performance 2 intensities shall be improved for frequent earthquakes, the seismic Grade may be adopted by reducing two intensities; but all Grades shall not be less than Intensity 6; being free from brittle failure For structure with middle tensibility, if the component bearing capacity is greater than the requirements that that one Performance 3
Intensity shall be improved for frequent earthquakes, the seismic Grade may be adopted by reducing one Intensity; but all Grades shall not be less than Intensity 6; otherwise, being adopted according to conventional design
Performance 4
M.1.2
Structure with high tensibility, still being adopted according to the relevant provisions of conventional design
When structural-component bearing capacity is rechecked according to various requirements,
earthquake internal-stress calculation & adjustment, earthquake action effect combination, material 219
strength value and checking method shall meet the following requirements: 1
Structural-component
bearing
capacity
under
precautionary
Intensity
includes
compression-bending, stretch bending, shearing and bending bearing capacities of concrete components as well as tension, compression, bending and stable bearing capacities of steel components. When rechecking is carried out according to the condition that the design value of earthquake effect adjustment is considered, fundamental combination of earthquake action effect corresponding to seismic Grade but not being counted into wind load effect shall be adopted; when the checking shall be carried out according to following formula:
γ G S GE +γ E S EK ( I 2 , λ , ζ ) ≤ R/γ RE
(M.1.2-1)
Where, I 2 —— Representing precautionary ground motion, seismically-insulated structure including horizontal seismic-reduced influence;
λ ——Adjustment coefficient of earthquake effect when seismic Grade is considered according to non-seismic performance design;
ζ ——Additional damping influence of energy-dissipation and earthquake-absorption structure or when reduced rigidity in plasticity of partial secondary component is considered Other symbol means are the same with non-seismic performance design ones. 2
When the bearing capacity of structural component is rechecked according to the condition
that the design value of earthquake action effect adjustment is not considered, the fundamental combination where wind load effect is not counted shall be adopted and checking shall be carried out according to following formula:
γ G S GE +γ E S EK ( I , ζ ) ≤ R/γ RE
(M.1.2-2)
Where, I ——Representing precautionary-Intensity ground motion or rare ground motion; seismically-insulated structure including horizontal seismic-reduced influence;
ζ ——Additional damping influence of energy-dissipation and earthquake-absorption structure or when reduced rigidity in plasticity of partial secondary component is considered 3
When the bearing capacity of structural component is rechecked according to the standard
value, standard combination of earthquake action effect when wind load effect is not counted shall be adopted and check shall be carried out according to following formula;
S GE + S EK ( I , ζ ) ≤ R K
(M.1.2-3)
Where, I ——Representing precautionary-Intensity ground motion or rare ground motion; seismically-insulated structure including horizontal seismic-reduced influence;
ζ ——Additional damping influence of energy-dissipation and earthquake-absorption structure 220
or when reduced rigidity in plasticity of partial secondary component is considered;
R K ——Bearing capacity being calculated according to standard material strength 4
When the structural component is rechecked according to the ultimate bearing capacity,
standard combination of earthquake action effect when wind load effect is not counted shall be adopted and check shall be carried out according to following formula;
S GE + S EK ( I , ζ )＜RU
(M.1.2-4)
Where, I ——Representing precautionary-Intensity ground motion or rarely ground motion; seismically-insulated structure including horizontal seismic-reduced influence;
ζ ——Additional damping influence of energy-dissipation and earthquake-absorption structure or when reduced rigidity in plasticity of partial secondary component is considered;
RU ——Bearing capacity being calculated according to the minimum limit strength of material; minimum limit may be adopted for steel strength; 1.25 times yield strength may be adopted for reinforcement strength and 0.88 times cube strength may be adopted for concrete strength M.1.3
When the inter-storey plastoelastic deformation of structurally vertical component under the
action of precautionary earthquake and rare earthquake is rechecked according to different control objectives; earthquake inter-storey shear calculation, earthquake action effect adjustment, component storey drift calculation and check method shall meet the following requirements: 1
Adjustment of earthquake inter-storey shear and earthquake action effect shall be carried out
with different methods according to different degrees of various parts in the whole structure entering into elastoplastic stages. When the whole component is in crack stage or is in yielding stage just the moment, equivalent rigidity and equivalent damping may be taken for estimation according to equivalent linear method; when the whole component is between bearing capacity yielding stage and the limit one, static or dynamic elastoplastic analysis method may be taken for estimation; when the whole component is in the bearing-capacity descent stage, dynamic elastoplastic analysis where descent stage parameters are counted shall be adopted for estimation. 2
Under precautionary earthquake condition, the initial rigidity of concrete component should
be the permanent one. 3
During the inter-storey plastoelastic deformation calculation of component, the calculation
shall be based on actual bearing capacity and gravity second-order effect shall be counted according to this code provisions; deformation under wind load and gravity action are not taken into consideration for earthquake combination. 4
For a component, the check of inter-storey plastoelastic deformation may be calculated
according to the following formula:
Δu P ( I , ζ , ξ Y , G E )＜[Δu ]
(M.1.3)
221
Where,
Δu P (…)——Gravity second-order effect and damping effect of vertical component being
counted under the action of precautionary earthquake or rare earthquake, depending on the elastoplastic storey drift angle of actual bearing capacity; for the structure whose aspect ratio is greater than 3, integral rotational influence may be deducted;
[Δu ] ——
Elastoplastic displacement angle limit, it shall be determined according to
performance control target; for the vertical component (in the entire structure) with maximum deformation, the slight damage limit may be half moderate damage one; the moderate damage limit may be the average value specified in Table 5.5.1 and Table 5.5.5; the non-severe damage limit is controlled according to less than 0.9 times the one Specified in Table 5.5.5 of this code M.2
Procedures on Design the Seismic Performances of Building Components and Building Auxiliary Facilities Supports
When
M.2.1
the
performances
of
non-structural
building
component
and
auxiliary
electromechanical devices are designed according to special usage function requirements, the requirements of the performance under precautionary-Intensity earthquake effect may be adopted according to Table M.2.1.
Table M.2.1Reference Performance Standards of Building Components and Auxiliary Electromechanical Devices Performance Function description
Deformation index
Possible appearance damage, but it not influence usage and
May endure 1.4 times building component and
standard
Performance 1 fire-prevention ability; safety glass cracking; usage and emergency equipment supporter design deflection appearing for system may operate as usual
the connected structural component
May basically be used normally or recover rapidly; fire r esisting May endure 1.0 times building component and time reduces by 1/4; strengthened glass breaks; during the operation Performance 2
equipment supporter design deflection appearing for of usage system after repair, the emergency system may operate the connected structural component normally Fire resisting time reduces significantly, glass drops off and the May only endure 0.6 times building component and outlet is obstructed with chips; usage system damages obviously and
Performance 3
equipment supporter design deflection appearing for it may only recover after repair; emergency system gets damaged the connected structural component but can operate basically
M.2.2
When seismic performance is designed for building enclosure seismic wall, auxiliary
component and fixed cabinet, the component type coefficient and function coefficient of earthquake action may be determined by referring to Table M.2.2. Table M.2.2 Type Coefficients and Function Coefficients of Building Non-structural Components Component type
Function coefficients
Components coefficients
Category B
Category C
222
Non-bearing outer seismic wall: Enclosure seismic wall
0.9
1.4
1.0
Glass seismic wall and etc.
0.9
1.4
1.4
Seismic wall connection piece
1.0
1.4
1.0
Veneer connection piece
1.0
1.0
0.6
Fire-prevention ceiling connection piece
0.9
1.0
1.0
Non-fire prevention ceiling connection piece
0.6
1.0
0.6
1.2
1.0
1.0
Goods shelf (cabinet) and filing cabinet
0.6
1.0
0.6
Antiquity cabinet
1.0
1.4
1.0
Connection:
Auxiliary component: Marks or signboard and etc. Support of cabinet being higher than 2.4m:
M.2.3
When seismic performance is designed for the support and connection piece of building
auxiliary facilities, the component type coefficient and function coefficient of earthquake action may be determined by referring to Table M.2.3.
Table M.2.3 Type Coefficients and Function Coefficients of Building Auxiliary Facilities Components Component type
Function coefficients
Belonging systems of components coefficients
Category B
Category C
1.0
1.4
1.4
1.0
1.0
1.0
Suspension or pendulum light fixture
0.9
1.0
0.6
Other light fixture
0.6
1.0
0.6
Cabinet equipment support
0.6
1.0
0.6
Tank and cooling tower support
1.2
1.0
1.0
Boiler and pressure vessel support
1.0
1.0
1.0
Common antenna support
1.2
1.0
1.0
Master control system of emergency power supply, generator and refrigerator etc. Bracing structure, track, support and palanquin guide component etc. of elevator
M.3
Floor Spectra Method for the Seismic Calculations of Building Components and Building Auxiliary Facilities 223
M.3.1
The floor spectra of non-structural components shall reflect the specific structure (bracing
nonstructural components) itself dynamic property, the storey position of nonstructural components as well as the ground motion amplification action of structural and nonstructural damping characteristic in structure location. During floor spectra calculation, single mass point model may be adopted for nonstructural components in general; while multi-supporting point system calculation should be adopted for the nonstructural components with relative displacement between supports. M.3.2
When floor response spectrum method is adopted, the standard horizontal earthquake action
value of nonstructural components may be calculated according to the following formula:
F = γηβ s G
(M.3.2)
Where, β s ——Floor response spectrum value of nonstructural components, being determined by precautionary Intensity, site condition, cycle ratio of nonstructural component to structural system, mass ratio, damping as well as the bracing position, quantity and connectivity of nonstructural components;
γ ——Functional coefficient of nonstructural component, being determined by building seismic precautionary type and operation requirements; being 1.4, 1.0 and 0.6 in general;
η —— Type coefficient of nonstructural component, being determined by such factors as component material properties, being within 0.6 ~ 1.2 generally.
224
Explanation of Wording in This Code 1
Words used for different degrees of strictness are explained as follows in order to mark the
differences in executing the requirements in this code: 1)
Words denoting a very strict or mandatory requirement: “Must” is used for affirmation;
“must not” for negation. 2)
Words denoting a strict requirement under normal conditions: “Shall” is used for affirmation;
“shall not” for negation. 3)
Words denoting a permission of a slight choice or an indication of the most suitable choice
when conditions permit: “Should” is used for affirmation; “should not” for negation. 4) 2
“May” is used to express the option available, sometimes with the conditional permit.
“Shall comply with……” or “shall meet the requirements of……” is used in this code to indicate
that it is necessary to comply with the requirements stipulated in other relative standards and codes.
225
