PROJECT NO. 55006
MAHANAKHON STRUCTURAL DESIGN CONCEPT REPORT 9TH NOVEMBER 2012
Reference: Z:\2555\55006 - Mahanakhon\Design\01.Etabs_MAhanakhon
6th Floor, 153/3 Goldenland Bldg. , Soi Mahardlekluang 1, Rajdamrit Rd., Lumpini, Patumwan, Bangkok 10330, Thailand Telephone: (662) 652 1366 Facsimile: (662) 652 1365 Email:
[email protected] Web: www.warnes.co.th
Disclaimer and Limitation
This report has been prepared on behalf of and for the exclusive use of Bouygues-Thai, and is subject to and issued in accordance with the agreement between Bouygues-Thai and Warnes Associates Company Limited. Warnes Associates Company Limited accepts no liability or responsibility whatsoever for it in respect of any use of or reliance upon this report by any third party.
Copying this report without the permission of Bouygues-Thai or Warnes Associates Company Limited is not permitted. It is important to note that if there is any conflict between the information provided in this report and the information provided in the drawings and specification then the information provided in the drawings and specification will take precedence.
Revision Record RE V
DESCRIPTIO N
A
Second Issue
ORIG
BTL APPROVA L
REVIE W
DATE
CLIENT APPROVA L
DATE
9th Nov 2012 S. J. Warne
Vanich. N
Distribution List NO.
NAME
1 2 3 4
MahaNakhon 55006
COMPANY
NO.
NAME
COMPANY
Bouygues-Thai Robert Bird Warnes Associates PACE
5 -
-
Archetype -
2
11 December 2015
CONTENTS CONTENTS ............................................................................................................................................................... 3 1
INTRODUCTION .............................................................................................................................................. 5
2
SCOPE ............................................................................................................................................................. 5
3
PROJECT AND PROJECT TEAM DETAILS AND INFORMATION ........................................................................ 6
4
DESIGN CRITERIA ........................................................................................................................................... 7 4.1 4.2 4.3 4.4 4.5
5
CODES .....................................................................................................................................................7 DESIGN DATA ............................................................................................................................................. 7 ANALYSIS SOFTWARE ................................................................................................................................... 8 DESIGN PEER REVIEW.................................................................................................................................. 8 TIME FRAME.............................................................................................................................................. 8
LOADING REQUIREMENTS ............................................................................................................................. 9 5.1 DEAD LOAD (D) ......................................................................................................................................... 9 5.1.1 Structural Self Weight ....................................................................................................................... 9 5.2 SUPERIMPOSED DEAD LOAD (SDL) ................................................................................................................ 9 5.3 LIVE LOAD (L) ...........................................................................................................................................10 5.3.1 Area Reduction ................................................................................................................................10 5.4 SOIL AND WATER PRESSURE (H) ...................................................................................................................10 5.5 WIND LOAD (W) ....................................................................................................................................... 11 5.5.1 Design Wind Speed for Strength Consideration ............................................................................. 11 5.5.2 Design Wind Speed for Service Consideration ...............................................................................12 5.6 SEISMIC LOAD ...........................................................................................................................................13
6
DESIGN LOAD COMBINATIONS .....................................................................................................................17
7
STRUCTURAL SYSTEM DESIGN ......................................................................................................................20 7.1 GENERAL DESCRIPTION AND GEOMETRY .........................................................................................................20 7.1.1 The Tower ........................................................................................................................................21 7.1.2 The Hill .............................................................................................................................................24 7.2 STRUCTURAL SYSTEM SUMMARY ..................................................................................................................25 7.3 STRUCTURAL SYSTEM .................................................................................................................................26 7.3.1 Sub-Structure ...................................................................................................................................26 7.3.2 Super-Structure................................................................................................................................39
8
DESCRIPTION OF SYSTEM BEHAVIOR ...........................................................................................................59 8.1 DEFLECTION CONTROL ................................................................................................................................59 8.2 FLOOR VIBRATION......................................................................................................................................59 8.3 HUMAN COMFORT ....................................................................................................................................59 8.4 L ATERAL STABILITY .....................................................................................................................................60 8.5 BUILDING BEHAVIOR ...................................................................................................................................60 8.5.1 Serviceability ...................................................................................................................................60 8.6 MODELING AND ANALYSIS ...........................................................................................................................62
9
OPERATIONAL AND PERFORMANCE REQUIREMENTS .................................................................................63
10
CONSTRUCTION ............................................................................................................................................65
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CONSTRUCTION MATERIALS AND PROPERTIES .......................................................................................65
12
NUMBERING SYSTEM ...............................................................................................................................66
13
APPENDIX A – EXTRACT FROM PUBLISHED LITERATURE THAT COMPARES OTHER RECOMMENDED METHODS INCLUDING ASCE.....................................................................................................................67
14
APPENDIX B – CALCULATION OF WIND FORCES FOR STRENGTH DESIGN FROM WIND TUNNEL TEST ..68
15
APPENDIX C – COMPARISON OF OCCUPANCY COMFORT CRITERIA (CASE STUDY) ................................73
16
APPENDIX D – LOAD COMBINATION (FULL) ............................................................................................76
17
APPENDIX E – 12 MODE SHAPES ..............................................................................................................79
18
APPENDIX F – WIND LOAD GRAPHS FOR 10 YEARS AND 50 YEARS (UNIFORM MASS) ..........................85
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1
I NTRODUCTION
The purpose of this report is to document the criteria and describe with illustrations, the structural design system of the MahaNakhon project in Chongnonsi, Bangkok, Thailand. It will go through each area of the project and describe in detail the design and changes to the Tower and Hill.
Our objective for the MahaNakhon project is to develop an optimised stable structure without any collapse either minimum or complete failure. Thus minimizing local damage, deformation and loss of structural integrity when and where appropriate. This objective will be met by complying with the design criteria which has already been set as part of the 7C-LOA and is also described in this report. By conforming to the codes and standards that the construction will be expected to achieve to reach the design intent.
2
S COPE
This report has been prepared as part of the detailed design documentation for the MahaNakhon project, the scope of the project is the Tower and the Hill and other provisions. This report will cover the following aspects: •
Project and project team details and information
•
Design criteria
•
Loading requirements
•
Load combinations
•
Structural system design
•
Description of system behavior
•
Construction materials and properties
•
Operational and performance requirements
The detailed design shall comply with the design criteria documented herein as a minimum. The document is maintained with the latest information available for design of the structure.
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3
P ROJECT AND PROJECT TEAM DETAILS AND INFORMATION
MahaNakhon is a 73-storey mixed used development tower situated in Narathiwat-Ratchanakarin Road, Chongnonsi BTS Station in Bangkok. The total area of the development is 150,000 m2 and comprises of residential, hotel and retail areas. The development is split into two areas, the Tower and Hill as one area and the other area is the Cube. The Tower comprises of most of the development and houses the residential and hotel areas. The Hill mostly houses the facilities for the residence and hotel, including the lobby, restaurants, swimming pool, fitness and other building amenities. The Cube which is not part of our scope of works will house the main retail area for the development. The surrounding area of the new development is in the commercial district consisting of urban development in all directions of the site such as office towers, residential buildings and hotels.
The parties involved in the project are provided in the organisation chart in Figure 1.1
Client PACE
Project Manager
Client Appointed Structural Engineer Review
Archetype
CPI
Design Architects Hok Lok Siew Co. Ltd and Palmer & Turner
ID, Façade & Landscape Architects
Main Contractor
Mechanical Engineer
Cost Consultant
Façade Consultants
Bouygues-Thai
P&T Bangkok
LangdonSeah
Façade Associates
Buro Ole Scheeren
Independent checker
Structural Engineer
Robert Bird
Warnes Associates Co., Ltd.
Figure 1.1 The Consortium
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4
D ESIGN C RITERIA
The information provided below were set as part of the “7C-LOA Structural Deign Criteria” and presented here as a reference.
4.1
Codes
This section describes the codes, and references used in the preparation of the design criteria and the methods of analysis for the structural design of the building. The standards, codes and references are used in our structural design and analysis as appropriate, and are listed as follows:
4.1.1
International Building Code (IBC 2006)/ASCE 07-05 for seismic design (in ref with the local response spectrum, seismic assessment Civil Park, June 2009.)
4.1.2
ACI 318-99: Building Code Requirements for Structural Concrete detailing)
4.1.3
AISC 2005 & AWS: for design and detailing of structural steel members & joints
4.1.4
AWS: American Welding Society
4.1.5
BS 6472 or ISO-10137 or ISO-6897 for vibration and human comfort
4.1.6
DPT 1311: for wind load on building and effects
(RC design &
4.1.7 CEB-FIB 900 or Equivalent: for relative shortening of vertical components & compensation 4.1.9
4.2
CTBUH 2008-Recommendations for the Seismic Design of High-rise Building: for performance based seismic design/evaluation of the tower- Appendix-B, which shall prevail (overwrite) all conflicting clauses of IBC 2006 (see Sec 4.1.1)
Design Data •
Wind Tunnel Test report from Civil Park International and TU-AIT WT Lab Bangkok, March 2009
•
Site Specific Seismic Hazard Study by CPI, June 2009
•
Safe barrette capacity = 2,500 Tonnes per barrette “for factor of safety per barrette = 2”
In case of conflict between the above Codes (of same use), Thai regulation will be referred.
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4.3
Analysis Software
The analysis and design will be carried out using commercial software, in-house spreadsheets and manual calculations. The following software that will be used is described in Table 4.1.
Table 4.1 Structural software Software
Use
ETABS V9 or SAP2000 V14
Overall 3D Analysis and Design Except for the detailed design of including requirements of CTBUH mat foundation and special 2008, Appendix-B elements
SAP2000 V14
Advanced modeling and Analysis
To supplement the limitations of ETABS
Design of Slab system (RC/PT)
Entire floor model shall be used
SAP2000 or Sofistik V23
Design of Mat Foundation
For final design of mat
CSI Column or PCA Column
Design of Column and Shear wall
If used, time and manual input aspects to be re-considered.
PLAXIS 3D Foundation
Design and study of foundation
To supplement the design and study of the mat
SAFE or CEDRUS
4.4
ADAPT
or
Remark
Design Peer Review
All the important items including but not limited to the overall design approach, design criteria (additional), methodology, procedure, parameters, modeling, analysis, design, detailing & performance checks shall be reviewed by BTL’s internal peer reviewer before formally submitting to Employer’s Technical Team (ETT) for independent review and consensus.
4.5
Time Frame
Mutually agreed time frame shall be set for preparation, review, feedback and necessary action.
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5
L OADING R EQUIREMENTS
5.1
Dead Load (D)
Dead loads are the vertical load due to the weight of all permanent structural and non structural components fastened thereto or supported thereby, including fireproofing and insulation.
•
Reinforced Concrete density
:
2,400
kg/m3
•
Steel density
:
7,850
kg/m3
•
Soil density
:
1,800
kg/m3
•
Water density
:
1,000
kg/m3
•
Wood density
:
900
kg/m3
5.1.1 Structural Self Weight The self-weight of structural elements will be calculated based on the member geometry and material densities.
5.2
Superimposed Dead Load (SDL)
Superimposed dead loads are the gravity vertical load due to the weight of permanent structural and non structural components fastened thereto or supported thereby, including fireproofing and insulation. •
Ceiling & Services
:
50
kg/m2
•
Screed/Finishes
:
120
kg/m2
•
Partition – Hotel*
:
200
kg/m2
•
Partition – Retail*
:
150
kg/m2
•
Partition – Apartment*
:
250
kg/m2
•
Roof/External Finishes
:
400
kg/m2
•
Façade-Glazed
:
100
kg/m2 of facade
•
Façade Concrete
:
360
kg/m2 of facade
*These partition loads could be replaced by linear loads where appropriate
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5.3
Live Load (L)
Live loads are all movable loads including personnel, tools, miscellaneous equipments, movable partitions, part of dismantled equipments and temporary stored materials. •
Inaccessible Roof (Not Concrete)
:
50
kg/m2
•
Accessible Roof/ Shade (Concrete)
:
100
kg/m2
•
Hotel & Apartment
:
200
kg/m2
•
Hotel, Apartment & Office: Lobby, Corridor & Staircase :
300
kg/m2
•
Retail & Restaurant: Lobby, Corridor & Staircase
:
500
•
Retail, Restaurant, Bar & Hotel Function Room
:
400
kg/m2
•
Kitchen (Restaurant)
:
500
kg/m2
•
Car Park
:
400
kg/m2
•
Storage & Fitness
:
500
kg/m2
•
Office
:
250
kg/m2
•
Fire engine and truck access – Uniform
:
*2000 kg/m2
•
Pool/Jacuzzi
:
Based on water depth
•
Water/Surge Tanks
:
Based on water depth
•
MEP Plant Rooms**
:
250 – 1500 kg/m2
•
Helipad Zone
:
500 – 1000 kg/m2
•
Balcony Landscape Area
:
kg/m2
Based on soil depth
* Uniform load **Where applicable except on the slab edge and cantilever
5.3.1 Area Reduction Area reduction is applicable to live load and will be applied as permitted by the Ministry of interior, Building Act 6, B.E. 2527, section 19.
5.4
Soil and Water Pressure (H)
The active and/or passive pressure exerted by soil (He) and water (Hw) shall be considered when its effect to the foundation and structure design is not negligible. Type of earth pressure, i.e. passive or active, shall be selected as appropriate in design.
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5.5
Wind Load (W)
The design wind load shall be based on High Frequency Force Balance (HFFB), Wind Tunnel Test (WTT) carried out by Civil Park International and TU-AIT WT Lab Bangkok, March 2009.
The objectives of the wind tunnel study were: •
To provide wind loading information for the overall structural design
•
To determine the wind induced accelerations at the higher levels
This development has the following special characteristics •
Close spacing of many high-rise buildings
•
The irregular geometry of the floor area
Figure 5.1 Wind Zone Map of Thailand with corresponding wind speed design
5.5.1 Design Wind Speed for Strength Consideration According to the DPT Standard 1311-50 the reference velocity pressure, q, for the design of main structure and cladding shall be based on a probability of being exceeded in any one year of 1 in 50 (50-year return period) corresponding to reference wind speed of 25 m/s at the height of 10 m in open terrain. Because the proposed building is located in the Central Bangkok with heavy concentrations of tall buildings, the exposure C (center of large cities) was applied in this study, and the typhoon factor = 1.0. Then design wind speed is 25 m/s, and corresponding to design wind speed of 36.65 m/s at 310.0.5m (According to - BKK Chongnonsi Architectural Drawings, For Coordination, Hok Lok Siew Design Co., Ltd, 31st August 2012) roof height in exposure C.
For strength consideration with V50 (i.e. high return periods of wind velocity and high stress levels), three natural frequencies (0.8 fo, fo, and 1.25 fo) of studied buildings in each direction of motion, and two damping ratios (0.01 and 0.02) were considered.
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5.5.2 Design Wind Speed for Service Consideration For the serviceability design, the reference velocity pressure, q, shall be based on 10-year return period corresponding to reference wind speed of 20.25 m/s at the height of 10 m in open terrain. Therefore, corresponding design wind speed is 29.69 m/s at 310.05m (According to - BKK Chongnonsi Architectural Drawings, For Coordination, Hok Lok Siew Design Co., Ltd, 31st August 2012) roof height in exposure C. Figure 5.2 and 5.3 illustrates how the wind loads per 7C-LOA WTT HFFB were entered into ETABS and used in the model.
Figure 5.2 Static load cases for ETABS
Figure 5.3 Values for wind loads
Refer to Appendix E for all wind load graphs for both 10 years and 50 years.
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5.6 Seismic Load The earthquake load shall be entered using the outcome of the Site Specific Seismic Hazard Study by Civil Park International (June 2009).
The earthquake load has been applied as a response spectrum curve with a damping ratio of 5% with our own interpretation of the study and to confirm with the LOA addendum and table 9.1. It is assumed that Appendix B of the CTBUH guidelines applicable fore regions of low seismic activity will be adopted for the analysis and design of Mahanakhon Tower. The guidelines require the seismic hazard to be based on the man 2475 year maximum direction spectrum for response-spectrum analysis in which the damping ration in any mode associated with the first 90% of the reactive mass in no greater than 2%. Accidental torsion need not to be considered in the analysis. It further goes on to state that the literature (e.g. ASCE 7, Eurcode 8) provides equations and tables to transform a 5% damped spectrum to a more lightly damped (e.g. 2%) spectrum. Eurocode provisions for response spectra and damping correction uses a formulae. Thus the value of the damping correction factor η can be determined by the expression:
, where ß is the value of the viscous damping ratio of the structure, expressed in percent. If for special studies a viscous damping ratio different from 5 % is to be used, this value will be given in the relevant Parts of Eurocode 8. See Appendix A for more information.
ASCE 07-05 provides the relationship between 2500 and 500 year seismic events as 1.5 which is consistent with the CPI response spectra in their report (refer to the MahaNakhon Structural Design Schematic stage 100% - Phase II (CPI, Jan 15, 2010). However there is no relationship provided for the 50 yr return period in that document and the values quoted in the Structural Report are from the New Zealand seismic code that provides a comprehensive set of relationships. For this project the values given in the CPI reports for 2500 yr return need to be adopted and also a way determine the 50 yr return to satisfy Appendix B CTBUH requirements. Thus the use of the New Zealand code values, the codes provided the relationship between the various return periods.
The seismic hazard is based on the mean 2475-year maximum direction spectrum; however the return period has been taken at 2500 years. The relation between the seismic load of 2500 and 500 years return period can be followed in the New Zealand code: •
The response spectrum value of 2500 yrs return period is 1.5 x 500 yrs return period given in the study.
•
The response spectrum value of 50 yrs return period is 0.35 x 500 yrs return period given in the study.
For the reduction factor, damping ratio and other parameters, refer to table 9.1. The 2500 years was used for the ultimate and the 50 years was used for the service, which are in accordance with IBC/ASCE. The response spectrums for these two scenarios are shown below in figure 5.4 and 5.5:
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Figure 5.4 Response spectrums for 50 yr return period
Figure 5.5 Response spectrums for 2500 yr return period
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The building has been analyzed for four basic response cases as shown in the figure 5.6. There are two cases for each direction, in the x-direction and in the y-direction. •
Primary x-direction
•
Primary x=direction plus 30%
•
Primary y-direction
•
Primary y-direction plus 30%
Figure 5.6 Response spectra
Figure 5.7 Response spectrum function definition
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Figure 5.7 illustrates how the translation of information was inputted into ETABS to model the building.
The CQC method was used to combine modal responses, shown in figure 5.8. The effect of multidirectional earthquake loading was considered thus the simultaneous application of the maximum spectrum (30% maximum spectrum) was used along each principal axis of the building as described above.
Figure 5.8 Response spectrum modal combinations
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6
D ESIGN L OAD C OMBINATIONS
Load combinations will be developed with appropriate load factors for the determination of maximum loads on foundations and the design of structural members following the code stated below: •
ACI 318-99: Building Code Requirements for Structural Concrete strength combination
•
BS8110 for the PT design
Table 6.1 Load Nomenclature Load Nomenclature D L W H
Description Dead Load (including self-weight of the structure) Live Load Wind Load as confirmed in The wind tunnel test study report Soil and water pressure
Table 6.2 Load Combination for serviceability of the structure, piling and steel design Case
Load Combination
1
D+L
2
D +L+H
3
D+L+W
For load combinations subjected to temporary loading, the material strength shall be increased by 33.33% for allowable stress design method.
Table 6.3 Load Combination for reinforced concrete design Case
Load Combination
1
1.4 D + 1.7 L
2
0.75( 1.4 D + 1.7 L + 1.7 W )
3
0.9 D + 1.3 W
4
1.05 D + 1.28 L + 1.4 E
5
0.9 D + 1.43 E
6
1.4 D + 1.7 L + 1.7 H
7
0.9 D + 1.7 L + 1.7 H
8
1.4 D + 1.7 H
9
0.9 D + 1.7 H
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Table 6.4 Load Combination for post tension design (BS8110) LOAD TYPE Load Combination
Dead
Imposed
Earth and water Wind Adverse Beneficial Adverse Beneficial pressure
1. Dead and imposed (and earth and water pressure)
1.4
1.0
1.6
-
1.4
-
2. Dead and wind (and earth and water pressure)
1.4
1.0
-
-
1.4
1.4
3. Dead and wind and imposed (and earth and water pressure)
1.2
1.2
1.2
1.2
1.2
1.2
Table 6.5 Serviceability Load Combination Load Nomenclature D+L D+W
Load combination
SDL
1.0 D + 1.0 L
SDW1
D + 1.0 W
SDW2
D - 1.0 W
Table 6.6 Ultimate Load Combination Load Nomenclature D+L
D+W
D+L+W
Load combination
UDL
1.4 D + 1.6 L
UDW 1U
1.4 D + 1.4 W
UDW 2U
1.4 D - 1.4 W
UDW 2L
1.0 D - 1.4 W
UDW 1L
1.0 D + 1.4 W
UDLW 1
1.2 D + 1.2 L + 1.2 W
UDLW 2
1.2 D + 1.2 L -1.2 W
Note: The load combinations can be found in Appendix D, which will be applied in the ETABS model.
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7
S TRUCTURAL S YSTEM D ESIGN
7.1 General description and geometry
Sky bar/restaurant
High-rise residential floors
The Tower
Residential floors
Hotel floors
The Hill
Figure 7.1 MahaNakhon and its components
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7.1.1 The Tower The Tower is a 73 storey structure. It comprises of a 7 storey podium and 1 storey basement (more detail in 7.1.2). The tower building itself consists of 10 storeys of hotel space and residential accommodations are provided on the 53 storeys above with the top 3 storeys being a sky bar/restaurant. It has a regular rectangular floor plate with a central square reinforced concrete core. However, on the residential floors, some of the floor plate are recessed this is due to the architectural concept called a pixelation effect. This pixelation starts at floor 20 and finishes at the roof deck. The building core steps in at 2 locations, at levels 20 and 52 creating larger floors spans for the residents. The floor plates to be considered in the design are shown in Figure 7.2, 7.3 and 7.4.
Cantilever slab with a nominate span of 8770mm.
Figure 7.2 Levels 11 to 19 (Hotel floors)
The hotel and apartment building will provide five star accommodations for the project. The key design considerations which contributed to the development of the structural scheme were: •
Designing columns which did not impact the room layouts
•
Providing large open spans for the hotel and apartments
•
Providing a floor system with good sound insulation qualities
•
Ensuring the structural depth of the floor system was kept to a minimum
•
Ensuring the proposed solution can be constructed in a safe, efficient manner which allows the Contractor to meet the construction programme
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Cantilever slab with a nominate span of 8770mm.
Figure 7.3 Levels 20 to 50 (Residential floors with a recessed core and pixelation)
Cantilever slab with a nominate span of 8770mm.
Addition transfer columns for the high-rise apartments.
Figure 7.4 Levels 50 to roof (Residential floors with a recessed core and pixelation)
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The floor plates in the tower will consist of a two concepts. The first concept uses post-tension band beams (2000mm x 450mm) and RC slab which incorporates the use of RC corner columns which will be supported below by the transfer levels to shorten the cantilevering corners. The other concept is to use deeper post-tension band beams (2000mm x 600mm) with RC slabs so that the cantilevering corners are freestanding without the support of the corner columns. Instead of the RC columns, vibration control damping struts will be used. These struts will be either concrete or structural steel. The corner will have to be free standing because there is no support accessible from the transfer levels due to the pixilation of the building. Figure 7.5 demonstrates the two different concepts.
The red line represents the RC corner columns that are supported by the transfer level below.
The blue line represents the vibration control damping struts.
The pixilation of the building creates gap between floors which in turn makes it difficult to have supports The diagram illustrates that there is no supported from the transfer level
The transfer level
Figure 7.5 The different corner supports
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7.1.2 The Hill The Hill comprises of one basement level and 7 podium level, refer to Figure 7.6 for an elevation of the Hill.
Figure 7.6 The Hill – section drawing
The basement level will have park for both hotel guests and residents along with other services, back of house facilities, MEP and storage areas. The podium areas consist of the facilities for the residence and hotel, including the lobby, restaurants, swimming pool, fitness and a 7 storey car park among other amenities. The Hill will span very large areas which will be supported by reinforced beams and slabs.
An architectural movement joint will be provided to divide the Tower and the Hill structure into parts (see figure 7.7). The location of the architectural movement joint will have to be coordinated with the architects to ensure minimal impact to the floor finishes. For more information refer to the movement joint report, 30th October 2012.
Figure 7.7 Structural movement joint (left)
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7.2
Structural System Summary
The structural system design is categorized into the sub-structure, super-structure and the transfer structures. Below in table 7.1 it describes the different categories and its components with brief description and comments. Each of them will then be explained further in the sections thereafter.
Table 7.1 Structural System Summary Main Components
Subcomponents
Description
Remarks
Pile Foundation
Barrette pile system 1.2m x 3m (tip 65m) and bored piles 0.8m & 1m diameter (tip -65m)
Constructed prior to this design analysis. The contractor guarantees the loads at 2500 tonnes. (Not in scope of works)
Mat Foundation
A proposed system (4.5m–9.0m deep); Reinforced concrete
Refer to table 11.1
Sub-Structure
Diaphragm Wall
Type A: 0.8m THK (tip - 18m) Type B: 0.8m THK (tip - 16m) pile legs are only around the Hill
Core Wall
Reinforced concrete with a maximum thickness of 1000mm
Columns
12 No. square reinforced concrete columns Hotel Floors (level 8 – 18) Post tensioned band beams and reinforced concrete slabs
SuperStructure Floor Slabs
Residential Floors (level 20 – 68) Post tensioned band beams and reinforced concrete slabs/PT slabs (in development) Sky Bar/Restaurant (level 69 – 73) Post tensioned band beams and reinforced concrete slabs/PT slabs (in development)
Transfer Structures
Outriggers
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3 No. outriggers on levels 20, 36 and 52. Comprising of 3000mm x 600mm deep beams.
25
Constructed prior to this design analysis. (Not in scope of works)
The columns realign on level 19.
Large cantilevers of 9 m. large spans of up to 12 m. Pixilation causing resizing floor plates thus removing structural columns on high rise floors
Used to help vertical axial shortening and provide a stiffer structure.
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7.3
Structural System
Note: All structural changes will need to be coordinated with the relevant parties.
7.3.1 Sub-Structure The Tower is founded on a nominally 4.5m thick barrette supported mat. At the mat foundation, reinforced concrete will be placed at different depths to compensate for the barrette cut off level. The mat foundation has a haunch under the tower core and goes to a depth of 9m while the rest is at 4.5m (see figure 7.8). The raft is supported on 1.2m x 3m reinforced concrete barrettes with a tip of 65m.
The Hill will sit on a 4.5 thick bored pile supported mat. This part of the mat is supported on 0.8m & 1m diameter reinforced concrete 2500 tonnes capacity with a tip of 65m.
The mat foundation is still under development and the cellular core in the central region is being considered as an option to reduce the massive volume of concrete and the resultant heat of hydration. Note: Refer to Foundation Check and Design Report, 24th October 2012 for more detail
7.3.1.1
Barrettes, bored piles and Diaphragm Wall
Barrettes and bored piles were designed previously on the project, by consultant Civil Park, and installed by SEAFCO. Warnes Associates have based their analysis of the current foundation system with the available information as follow: Soil Report – Subsurface investigation for BKK Chongnonsi project at Narathiwas Road Bangkok, dated March 13, 2009, from STS Instruments Company Limited Report on Static Pile Load Test on an instrumented test pile barrette size 1.20x3.0x66.0m (Test panel #33), August 2011, from STS Instruments Company Limited Report on Static Pile Load Test on an instrumented test pile barrette size 1.20x3.0x56.0m (Test panel #BP19), August 2011, from STS Instruments Company Limited Report on Static Pile Load Test on an instrumented test pile barrette size 1.20x3.0x65.76m (Test panel #BP1A-09), January 2012, from STS Instruments Company Limited Barrette As-built drawings, by SEAFCO, received by BTL on August 14, 2012
It is to be noted that Bouygues Thai Limited requested additional information about the barrette and D-wall design, as per RFI 15, and the answer was that the above information were enough to assess the raft design. So, the installation, inspection, quality control records, relevant design and analytical information, and expert reviews relating to the foundation system were not made available to Bouygues thai Limited and Warnes Associates at contract and afterwards.
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The work described in this report was initially carried out to get the pile reactions to design the Mat footing. Preliminary analysis described in below section (Piglet/ADAPT) were done in a view of getting these pile reactions. When Warnes Associates discovered that the piles were above safe loading limit, it was then necessary to make a more detailed analysis that would give more defined results and maybe prove that the first approach was wrong and that the safe loading limit was not overpassed.
Figure 7.8 The barrettes, bored piles and the d-wall pan
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7.3.1.2 Mat Foundation (Provisional) As that the barrettes, bored piles and the d-wall have been installed previously, SEAFCO have explained that the working load to be at 2500 tonnes. This is portrayed in the soil report: STS job No. 12474, March 13 2009. However no design consultants/geotechnical engineers for the project verified and certified the work by SEAFCO. There has been limited information and reports provided to the principal contractor for review. Referring to the MahaNakhon Structural Design Schematic stage 100% - Phase II (CPI, Jan 15, 2010) section 5.1.3 has provided some indication of the previous mat foundation. The analytical method being used presently is based on this CPI report. While a preliminary design of the mat footing was carried out during the tender period, it is only after date of LOA that a detailed analysis, including foundation check, was performed. The “shape” of the mat was very much controlled by constrained by the existing diaphragm wall toe level, as well as Basement 1 structural level did not allow for a perimeter mat thicker than 4.5m. Several sensitivity studies were done with different shapes for the mat foundation, in order to understand the relationship between the mat and the foundations, and the best shape to use so as to spread loading evenly onto the piles. The detail of these studies is presented in the below section “Sensitivity studies”.
The final design shape of the Mat Footing resulted from the combination of the following constraints, in order of importance: Constraint of Basement 1 structural floor level (-4.50m) and the level of the deeper barrette (14.50m) – this gave the maximum volume the mat could have. Constraint from the Diaphragm Wall length (-18m) which cannot hold deep excavation. One pile wall has already been added to counteract the soil/water pressure during excavation. The objective was not to add an additional pile wall. This gave the triangular shape of the mat with deeper excavation only in the middle (where necessary for elevator pits). Below sensitivity studies to find the best final shape.
The result is a mat foundation that is: 4.5m deep under the podium areas and the surrounding of the Tower 9.0m deep in the central/core area No post tension is necessary as rebars can counteract shear and moments
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Figure 7.9 Mat foundation (East – West Section)
Figure 7.10 Mat foundation (North – South Section) The Tower & Hill raft is supported on 1200mm x 3000mm reinforced concrete barrettes that extend 65m below the base of the mat.
The detail design of the raft foundation will be described in another report. In order to mitigate the risks, the following factors will be taken in consideration: Interaction with barrettes and bored piles Interactions with diaphragm wall Short and long term settlement Tilt Strength and stability The lateral force analysis of the superstructure is not yet completed, this report is still based on the gravity force only but it is believed that this case likely to be governed almost every case. When the
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superstructure analysis is finished then all the load cases can be checked. However the revision will be only minor. Since the gravity case shall govern most of the case.
7.3.1.3 Analysis Method Warnes Associates have carried out this study using the basic information available with advice from geotechnical experts of high academic standing with knowledge and experience of foundation conditions in Bangkok.
The investigations included the following: Rationalisation of super structure gravity loads that would be transferred to the foundation system. First approach on foundation check with Piglet/ADAPT analysis (primary analysis software), that showed that further investigations were necessary Full 3D non linear analysis using iterative approach between ETABS / Plaxis 3D / SAP 2000 giving exact results for soil behavior, stiffness ratio, settlements and pile reaction.
So that the following analysis could be run: Foundation - structure interaction study using the barrettes that have been installed to date. The study included several iterations using raft and superstructure stiffness as variables to redistribute the pile loads. For the results of this analysis refer to Foundation Check and Design Report, 24th October 2012 in section “Existing Foundation Analysis results”. The study showed that a significant number of barrette reactions exceeded the safe load capacity of 2500 tons specified by the installers. Foundation- structure interaction study using additional barrettes to limit the reactions to the specified safe load capacity of 2500 tons. The study revealed that 23 additional barrettes and 11 additional bored piles were required to meet the limiting criteria. For the results of this analysis refer to Foundation Check and Design Report, 24th October 2012 in section “Analysis results for piles under 2,500T”. Foundation- structure interaction study using additional barrettes with enhanced safe load capacity of 2900 tons. The study revealed that 14 No additional barrettes and 2 No. additional bored piles were required to meet the enhanced limiting criteria. For the results of this analysis refer to Foundation Check and Design Report, 24th October 2012 in section “Option 1 – Analysis results for pile capacity 2,900T”.
The analytical techniques used in this study are based on well established design practice for foundation systems and they have been subject to expert review. At this stage the study is limited to gravity load effects and further analytical work will be carried out to evaluate the impact of lateral loads induced by wind and seismic effects.
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First approach: Piglet / ADAPT Analysis Piglet software is used for preliminary calculation check. Our analysis has estimated an average spring stiffness using the PIGLET software (pile group analysis). This stiffness is then entered in an ADAPT structural model. A first calculation calibrates the soil parameters against the load test results. The result gives the applied load and the calculated settlement of the pile. Then a second calculation models all barrettes without consideration of the raft slab above. The result gives the reactions for each barrette and the overall settlement. Total applied load / settlement gives the average stiffness of the barrettes considering the group effect. The settlement is about 10cm. These data are input into a ADAPT model that gave a first assessment of the barrette reaction. The third calculation was to input the reaction distribution from previous ADAPT run with high barrette stiffness. The first assessment of the barrette reaction, assuming all springs have the same stiffness, was that many of them were loaded more than 4,500T. The result gave more reaction in the centre and more deflection in the centre.
Figure 7.11 Extract of ADAPT results – vertical deflection
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Figure 7.12 Pile reactions from Piglet/ADAPT analysis – see Appendix C
It is true that the assumption that “all springs with same stiffness” is not accurate, but it enables the designer to get a first check on the structure. In our case, this is the reason why, Warnes Associates have decided to go in further analysis with complex 3D non-linear analysis in order to refine the results and if possible assess that the existing foundations could hold the Tower and Mat, while the reaction of them kept under 2,500T.
3D non-linear analysis of foundation – ETABS / Plaxis 3D / SAP 2000 The proposed technique for 3D analysis is to carry out a non-linear soil-structure interaction analysis using finite element software such as PLAXIS. This method uses the soil characteristics from the geotechnical report and the barrette load test reports, which are appropriately calibrated together and input into the programme. This particular process can be used to provide a set of linear spring stiffness values (K) for the analysis and design of the raft. This program also provided estimation of the behavior of the pile group effect or dishing effect. The process of this study starts with the design of the ETABS model to produce the gravity loads of the building. The working load is used to check the reaction of the pile and the ultimate load is used to check the pile section along with the mat foundation reinforcement design. These load are then used in the Plaxis 3D to analyze the pile group behavior and pile spring stiffness. The spring stiffness will be input to SAP 2000 in order to analyze the stress and force of the Mat foundation and barrettes. The detail of each step of this analysis is provided below:
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Figure 7.13 Process flow chart
Step 1: Input all the geometry and force into ETABS – run program and recheck Step 2: Input the soil profile, pile layout and loading from ETABS. Plaxis will calculate the effect of pile group; which will provide stress and settlement of each node around the piles. By using Excel to obtain the average stress it will result in getting the reaction and settlement, from this the pile spring stiffness can be calculated Step 3: Input the original pile layout with the K-value and run the program, this will show where the overloaded piles are. Piles will be added and program rerun, adjust the pile location until the pile reaction meets the requirement pile capacity. Step 4: Input the column and core settlement into the ETABS. The result will present new reaction on mat foundation Step 5: Input the new load into SAP 2000 to see if there is any effect on pile design after settlement, if so, adjust the pile design accordingly. If the final settlement does not exceed the previous model by 10%, the analysis will be completed.
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Plaxis analysis Each layer of soil is represented into finite elements, with its own characteristics.
Figure 7.14 Soil layers and characteristics input in PLAXIS
The analysis on PLAXIS is a process where many operations are necessary to get the stiffness of each pile. First, it is necessary to input the soil profile, pile layout and loading from ETABS results. After the program calculates the effect of pile group, and gives the stress and settlement of each node around the piles. The long process is then to input all information at each node, coming from all adjacent 3D finite elements to gather the final result. This is done in Excel, where all reaction and settlement are input to obtain the average stress in every node. At this stage, the average stress value is re-input in the model, so that it can calculate the pile spring value to use in next step analysis (with SAP). Each iteration or change of design uses about one week to proceed.
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Figure 7.15 3D views of the model with layers of soil hidden to see the barrettes
Figure 7.16 Example of output of spring stiffness by PLAXIS
Due to the limitation of PLAXIS program on the amount of degree of freedom, the following simplifications were made: •
Mat foundation is modeled at ground level not -10 to -15.00 m
•
Soil parameter have been input from 0.00 to -80 meter, we have run the design check to verify the difference between piling behavior of -80 and -90 meter and found very insignificant difference (1mm different)
•
Line load from the diaphragm wall and ground floor, applied at the edge of Mat foundation are estimated at 100 T per running meter.
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SAP 2000 results The technique adopted uses SAP 2000 (a finite element analysis program) to simulate the soil structure interaction with elastic springs. The springs represent the pile reactions. The raft foundation is intended to re-distribute the pile loads based on their axial stiffness characteristics as a group. Therefore the assumption is that when a single pile is overloaded it will shed its load to the adjacent piles via the raft, which needs to have the strength and stiffness to transfer the load. The analytical technique is an approximate simulation of a more accurate non-linear soilstructure interaction analysis.
Figure 7.17 SAP 3D finite element analysis of the mat foundation
The load is redistributed by the combination of interacting soil-pile layers and the raft. The springs simply represent the foundation and ground response to the superstructure loads distributed by the raft. In this technique several iterations are required with variable foundation spring stiffness values in order to obtain a distribution that limits the pile loads. The group action and consolidation effects are captured by appropriately softening the springs to suit the pile group efficiency. The raft is then designed to suit the resulting curvature induced moments and shear forces.
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Figure 7.18 Example of output of raft settlement with SAP
Figure 7.19 Example of output of pile reaction with SAP
In the first results that we got from the analysis, the pile reactions indicated that the system does not adequately redistribute the pile loads. This is due mainly to the eccentricity of gravity load in relation to the pile reactions. The next step in this exercise has been to change the elastic spring stiffnesses to follow the load pattern instead of changing the raft thickness as the soil-pile stiffness is likely to be higher than that of the raft. This can be achieved by reducing the spring stiffness in the regions where the high pile reactions are experienced from the initial values.
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Eccentricity An eccentricity of center of gravity from the barrettes and from the tower has been found and measures around 3m. Eccentricity of centers of gravity and reaction can cause tilting of the foundation system. However eccentricity is unavoidable and 3 meters in this instance over the extent of this raft is relatively small and is unlikely to cause significant tilt. It will show up in the PLAXIS analysis and the numerical impact on the tower verticality can be verified. Moreover this will occur while the tower is getting built and will get partially corrected with surveyed alignment corrections progressively. The tilt effect is a result of the soil pile stiffness and load distribution and not based on the safe load capacity as long as the load settlement behavior is within the linear elastic range. Once again the magnitude of settlement and tilt can be determined form the output of the PLAXIS analysis and the settlement contours.
Sensitivity study During the study, it was necessary to check the behavior of the pile reaction with the mat foundation design. In order to design the most time and cost effective design for foundation, a sensitivity analysis was carried out to measure how the load distribution could be improved by a stiffer mat footing.
Seven calculations were carried out, with loads on one of the most heavily loaded barrette and on one of the least heavily loaded barrette hand calculated from the “user-unfriendly Plaxis output”. Short term and long term concrete E values were used.
0) Benchmark scenario: E-short term / 4.5m thick perimeter mat / 9m thick plain central mat. Max load over 4000t, min load below 1000t. The easternmost row of barrettes are quasi useless.
1) Comparative scenario (using E-short term except noted otherwise) 4.5m / 18m: results not significantly improved 4.5m / 4.5m: results a bit worse than benchmark 4.5m / 9m cellular (with 50% x concrete density input): results similar to 4.5m / 9m plain 4.5m / 3m: results are much worse than any others 6.25m / 9m: results are marginally better than with 4.5m perimeter raft
2) Benchmark with long term E (E-short term x 50%) to simulate creep effect on mat and barrettes: Results are marginally better than benchmark short term
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The conclusion of the sensitivity analysis is: The marginal benefit of a 6m thick perimeter raft could not balance the much higher construction risk (D-wall instability), An 11m deep cellular raft (central part) and 4.5m thick plain raft (perimeter part) were the best raft design, under the constraint created by the existing diaphragm wall, to distribute gravity loads onto the existing barrettes, Existing barrettes were insufficient to support MahaNakhon tower, at the specified safe working load of 2,500T
7.3.2 Super-Structure The 73 storey mixed use tower will provide the centre piece for the development. As such it was imperative that the structural design solution was sympathetic to the architectural design intent as well as providing an efficient, buildable structure. The key design considerations which contributed to the development of the final structural scheme were: •
Ensuring the self weight of the building was kept to a minimum to reduce the axial loads on the vertical support elements
•
Keeping the core wall thickness to a minimum through the provision of an efficient lateral stability system
•
Ensuring the column sizes are kept to a minimum to minimise impact to the lettable floor area
•
Ensuring the proposed solution can be constructed in a safe, efficient manner, accounting for availability of materials, construction techniques which allows the contractors to meet the construction programme
The main objective and design intent will be the development of an optimized functional scheme and an analytical model in relation to the gravity and lateral loads. This will be split into two parts:
Gravity load system • • •
Load paths and balancing (figure 7.20) Control of tower deflection under gravity load The differential axial shortening will be controlled by the outrigger
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Central Core
The loads in the building are transferred down the building thru the columns and core.
Outrigger floors Where there are outriggers, some the load from the columns shifts into the core. Perimeter columns
Transfer floor
Mat foundation Figure 7.20 Vertical load paths
The load is concentrated in the core causing more loads to be dispersed into the central areas of the
Lateral load system • • •
Resisting wind and seismic forces Performance requirements for deflection (see section 7.1) Occupant comfort (incl. vibration and acceleration)
This section will also include provisions for: • •
Requirements of the transfer structure Outrigger system (see below)
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7.3.2.1 Core Walls There are a several possible load reductions in the core walls by replacing some of the structural walls to non-structural dry walls, optimising the structure. Also the thickness of the structural walls will be reduced in width as much as possible without hindering the stability of the structure. This has been realized in the following areas.
Structural load bearing wall All the walls in this design are structural load bearing walls. The core acts as two or four separate cores instead of one complete unit
Figure 7.21-A Original Core Structure
Structural load bearing wall Non-load bearing wall In the new design the core acts as one core with the use of deep link beams between the floors. The wall widths have been optimised for their actual use for the building. Special care will be taken when designing the deep link beams (lintels) so that it will provide optimal support for the core. Also selection of internal wall and joints will need to be taken in careful consideration.
Figure 7.21-B Optimised core structure
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Colour
Width (mm) 11 December 2015
1000 900 725 500 300 150
In the original design there were too many thick walls because it was design as 4 separate cores instead of one, thus the need of thick inner core walls. In addition the walls inside the core did not take that much load compared to the perimeter wall
Figure 7.22-A Original core wall sizes
Colour
Width (mm) 1000 500 400 300 180
In the new design the outer core wall are thicker, adding to stiffness thus the inner walls can be reduced in thickness and in addition, not all of them have to be load bearing walls.
Figure 7.22-B Optimised core wall sizes
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The core is very important and part of it had to be designed early so that an accurate load could be calculated. Currently only the beam and slab have been designed to support the non-structural load bearing walls. Now that the design has changed by replacing some of the structural wall with nonstructural with beam supports. This was to optimise the core and reduce the overall weight. The details of reinforcement for each beam are not provided in this report. Figure 7.15 and figure 7.16 illustrate the non-structural wall detail (needs to be coordinated with other parties) and the floor slab detail. The non-structural wall detail follows on from figure 7.12-B where it shows the position of these walls.
Figure 7.23 Non-structural Wall Detail
Figure 7.24 Floor slab detail (inside the core)
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7.3.2.2 Columns From an ETABS analysis it demonstrated that the magnitude of the axial loads acting on the columns was very high, meaning that designing reinforced concrete columns would be the most efficient solution; concrete strength can be seen in Table 7.2. The columns are located on the perimeter of the floor plate around the core wall and are square in shape. The shape of the columns was dictated by the requirement to maximise the view through the façade glazing whilst minimising the depth which the columns protrude in to the floor space. These columns change sizes throughout the elevation of the building. The changes in column sizes are shown in Table 7.2.
Table 7.2 Mega Column Sizes Floor B1 - F7 F8 - F19 F20 – F30 F31 – F40 F41 - F51 F52 - Roof Transfer columns (F58 –Roof)
Concrete strength (ksc) 600 600 600 500 400 400
Column sizes (mm) 1800 x 1800 1600 x 1600 1400 x 1400 1200 x 1200 1000 x 1000 900 x 900
Main rebar ratio (%) -
400
800 x 800
-
In addition to the change in sizes of the columns, at one transfer level the columns incline closer to the core. The reason for this is that the core itself recess as the building goes up in height and by inclining the columns it will reduce the spans of the floor plates. The inclining columns can be seen in Figure 7.25.
Figure 7.25 Inclined columns at level 19 transfer level
With the inclining columns it will create horizontal and lateral forces and this will have to be countered by the outrigger system on level 20 and extra PT in the floor slabs on level 19. This will be a one-off floor design because of the special case of the inclined columns.
To optimise the core wall and floor plates the thickness of the wall in the core and on the slabs were reduced in the most appropriate areas from the original design to reduce the overall weight which will travel to the foundation. As that SEAFCO guaranteed the pile capacity at 2500 tonnes, the objective for the vertical supports was to carry less load. The other reason for the change was to balance the creep stress deformation. The DL and SDL must produce the uniform stress distribution at the same level of the core wall to prevent long term horizontal deformation from the creep stress.
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7.3.2.3 Floor Plate System The floor plates will be an optimised system to support the M&E equipment and architecture for both the hotel and residential floors in the building. This includes optimizing transfer structures, columns transitions, staircases, lift shafts, large cantilevers and post-tension concept. The optimized floor plate will reduce the impact of the deflection and vibration at the edges in the most appropriate fashion.
The main structural constraint for both the hotel and the residential floor plates are: •
The large cantilever corners (approx 9m)
•
The pixilation of the floor plates
•
The removal of structural columns
•
Recessing of core wall
•
MEP openings (columns and band beam lines)
•
Jacuzzi and swimming pool at floor plates cantilevers
As with the core walls the floor slab was either increased or decreased in thickness during the detailed design where it was necessary to carry the loads and also span the distances that were needed. This was done where it would optimise the structure and also help with building vibration. The changes in floor thicknesses are shown in Table 7.3.
Table 7.3 Slab Thickness Optimisation Floor B1 - F7 F8 F9 - F18 F19 F20 - F34 F35 F36 - F50 F51 F52 - Roof
Original floor thickness (mm) 200 200 250 250 250 250 250 250
Optimised floor thickness (mm) 150 – 250 250 (MEP) 200 – 250 250 (MEP) 200 – 250 250 (MEP) 200 – 250 250 250
The podium, the residential floors and the sky bar floors, respectively, will be further discussed in the next few sections.
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Podium The podium floors which make up the first seven floors of the building, level 1 to level 7 are going to be an RC slab and beam system. As that these floors are RC then they have been designed using structural software and manual calculations.
Figure 7.26 SAFEv12 model of Level 1
Figure 7.27 Reinforced Concrete Slab and Beams The 3D model demonstrates the frame work of the podium levels. As you can see there will be a large network of beams to support the floor plate.
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Hotel Floors The floors of the hotel which only house the rooms occupy only lower ten floors of the building form level 8 – 18. The floor plates will consist of post-tension band beams (2000mm x 450mm) and reinforced concrete flat slabs. Post tensioning will be kept only in the band beams so that construction can separate the two floor system easily. In Figure 7.28, it shows the post tension tendons going along the length of the floor plates; this helps with the profile because effective stressing of the tendons can be achieved. This is further illustrated in 3D in Figure 7.28.
The areas which are highlighted in red show reinforced concrete columns at the cantilever corner edges to help control the deflection and vibration of the floor plate.
Sufficient and appropriate pre-camber will have to be provided
Figure 7.28 ADAPT builder model
This development, as stated above will follow the American code, ACI-99 but for the post-tension it will follow British standard, BS8110. The PT will be classified as Class 3 with a crack width of 0.1mm to 0.2mm. This will be in coordination with the post-tension contractor.
The RC columns which are at the corner of the floor plates will be supported from the bottom by deep beams on the transfer levels; this will be explained in more detail in the transfer and outrigger structure section (below).
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Figure 7.29 3D ADAPT model
A finite element software program, ADAPT, was used for the analysis and design of the PT concept for the hotel floors. Material properties and imposed loads were entered, to get the deformed shapes of one level, for illustration purposes. The PT and the tendon profiles were modeled to see what the deflection outcome would be, for both service and ultimate load combinations (Figure 7.30-A and 7.30-B). There are 7 – 12 tendon ducts in the band beams which can be seen in Figure 7.28; the floor plate will be RC slabs (200mm THK).
Figure 7.30-A Service load deflection
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Figure 7.30-B Ultimate load deflection
From figures 7.30-A and 7.30-B it shows that the deflection are not symmetrical, this is mainly because at one corner of the floor there are no column supports and in addition the floor has different drop panels, recess and openings. However deflection is kept under the control limits which are stated in table 9.5b of ACI318-99.
Currently at levels 8, 9 and 10, the floor plates are not completely square and therefore the columns corners for the corner highlighted in red cannot be supported and thus cannot support the higher floor because there is no transfer deep beam in that corner on level 8. Therefore a transfer beam maybe needed on level 11, but this will have to be discussed at a later date with all consultants. It would be mutually beneficial to have these floors completely square also.
Figure 7.31 Hotel levels which do not have a square floor plate (right)
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Residential floors At the residential floors, which start at level 20; architectural features starts to come into play with the structure of the building. These features include the pixilation concept, large overhanging balconies, cantilevered Jacuzzis and additional staircases for the duplex condos. At these levels, the core wall has also been recessed one step in order to create more floor area for the condos; thus causing larger spans between the core wall and columns. As a result, the floor thickness or reinforcement required has to be increased.
The floor plates will consist of post-tension band beams and reinforced concrete flat slabs or PT slabs; this is still in development to produce the best option for the structure. If the first option is chosen then the post tensioning will be kept only in the band beams so that construction can separate the two floor system easily. However these floors are still in development and the option of mixing the two systems in the slabs (instead of separating them by band beam and slab) may have to be considered. This is because the balconies have a 200mm drop which cuts into the band beams and other drop panels, thus losing a lot of its support between the columns (see Figure 7.32). Additional staircase which creates a void, thus the lower floor plates will have to carry the load of the façade which spans two storeys.
Some balconies in certain condos are cutting into the line of the band beams, which are creating problems with the structure.
The pixilation concept along the edge and corners of the floor plates which recesses into the slab.
Figure 7.32 Pixelation floor plates
As stated, the RC design will follow the American code, ACI318-99 but the post-tension will follow British standard, BS8110. The PT will be classified as Class 3 with a crack width of 0.1mm to 0.2mm. This will be in coordination with the post-tension contractor. The deflection for the floor plates will be controlled using the formulas stated in table 9.5b of ACI318-99.
Different from the hotel floors, where there will be RC columns supporting corners of the floor plates (these columns, in turn, will be supported by deep beams on the transfer levels - this issue is to be
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explained in more detail below in the transfer and outrigger structure section), the residential floor has recessed floor plates because of the pixilation effect and therefore these RC columns will not be able to support the corners at every floor. Therefore, to support the free-standing cantilevers, another structural concept is chosen to take precedence - which is to have deeper band beams (2m x 0.6m), this will be in accordance with VSL and coordination with other consultants. After construction, to help these corners further with vibration and deflection, it is intended to install supporting struts from concrete or structural steel members. However the main concept is to have the cantilevers free-standing.
High Rise Residential Floors/Sky Bar At the highest floors, namely levels 53-73, the continuation of the pixilation effect causes the core wall to recess one more step. From level 53-57, due to the increment in the span between the core wall and the outer columns, it is proposed to introduce a second row of inner transfer columns to support the floors. From level 58 to roof, also as a result of the pixilation effect, the changes in shape of the floor plates would cause two rows of structural columns to be gradually removed. During this process of going upwards, there would be a few one-storey-span transfer columns to be installed to support the slabs.
A second row of inner transfer columns (level 53-57) is proposed to be introduced in order to support the floor span due to the core wall recession. From level 58 to roof, structural columns will be gradually removed also as a result of the pixilation effect.
The continuation of the pixelation concept along the edge and corners of the floor plates which recesses the core wall
Figure 7.33 Pixilation floor plates
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Column removed when the structure moves up from Level 57 to Level 58.
Figure 7.34 Removal of structural columns at Level 57-58 due to pixilation effect
To be consistent with the design concept of the rest of the tower, the RC elements on these floors are to follow American code ACI318-99 while the PT elements are to follow British standards BS8110. The structural concept thus far is to adopted RC flat slab supported by PT band beams and RC columns. However similar to the lower residential floors where there is no corner supports another structural concept to make the slab corners free standing, such as full PT band beam and slabs.
The increment of the inter-storey heights on these levels (from 3.7-3.9m at lower floors to 4.4m) would require more stringent observations on all serviceability requirements, which include the deflection of the cantilevered floor plates, the crack width/deflection of PT beams, the inter-storey drift as well as the overall drift of the tower.
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7.3.2.4 Outrigger and Transfer Structure The floor plates on the transfer levels will be double height MEP rooms with an outrigger system which are shown in Figure 7.35, located exactly where transfer/outriggers are.
Transfer/outrigger level at floor 51-52
Transfer/outrigger level at floor 35-36
Transfer/outrigger level at floor 19-20
Transfer System at floor 8 Figure 7.35 Transfer Structure locations
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The purpose of the outrigger floors are 4 folds: •
Assist against differential axial shortening in the columns for the creep deformation compared to the core wall where most of the building load is, thus balancing the settlement of the vertical supports
•
It also compensates for the shrinkage of the core wall, trying to balance it to the columns
•
Help against lateral loads such as wind and earthquakes thus providing a stiffer structure
•
Provide transfer deep beams for the corner columns and central columns at the higher floors of the building
Stability is provided by the central reinforce concrete core, the columns and reinforced concrete outrigger floors. There are deep link beams (lintels) which at the mezzanine levels which will make the building more rigid; this will help against the lateral loads as well as the vertical loads.
At floor 9 there is no outrigger system but a transfer system for the corner columns for the hotel floors. The transfer beams will be deep beams and the dimension are 600mm x 2000mm (red) and 600mm x 1000mm (yellow) and will be supported by the columns, see figure 7.36-A.
Figure 7.36-A Floor 9 framing of the deep transfer beams
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Figure 7.36-B Floor 9 framing of the deep transfer beams
At floor 20, 36 and 52 there are outrigger system which will act as transfer beams which will support the corners columns and at floor 52 there are additional transfer beams to support the central columns because as elevate to the higher floors the perimeter columns gets removed and thus the transfer columns comes into play and they also help with the large floors spans. The dimension of the beams that will be used for the outriggers are 600mm x 3000mm (red, pink and grey respectively) and 600mm x 1000mm (yellow). The framing of outrigger system can be seen in the figures below for level 20, 36 and 52.
Figure 7.37-A Floor 20 framing of outrigger and transfer system
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Figure 7.37-B Floor 20 framing of outrigger and transfer system
Figure 7.38-A Floor 36 framing of outrigger and transfer system
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Figure 7.38-B Floor 36 framing of outrigger and transfer system
Figure 7.39-A Floor 52 framing of outrigger and transfer system
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Figure 7.39-B Floor 52 framing of outrigger and transfer system
The outrigger systems have been modeled using ETABS to find the most effective frame for the deep beams. The concept shown above are the framing plan and the 3D model represented in ETABS. The forces that are being exerted on the outrigger levels have been calculated from the ETABS model of the Tower and Hill. ETABS program is being used for the outriggers because it can calculate the whole the building and the load interactions can be reviewed.
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8
D ESCRIPTION OF S YSTEM B EHAVIOR
8.1
Deflection control
Vertical deflection will follow the table 9.5b of ACI318-99, In addition, cantilever element will respect •
L/240 for the live load (L)
•
L/360 for incremental deflection (Long term total deflection – instantaneous deflection) (Where L = Span of Cantilever)
Lateral deflection on the wind load will be as follows: •
Overall maximum deflection is to be less than H/500 with 10 year return period wind.
•
Inter-storey drift limit is to be less than h/300 with 10 year return period wind. (Where H = building height & h = storey height)
Lateral deflection on the seismic load will follow the table 12-12-1 of the ASCE07-05
8.2
Floor Vibration
Criteria are quoted in terms of response factor (R). A response factor of 1 is intended to represent the threshold of human perception (i.e. the level of vibration that you can just perceive) and is defined formally in BS 6472. Depth of the band beam could be increased in order to respect this criterion.
8.3
Human Comfort
Allowable peak resultant acceleration at top floor: •
Once per year event = 12 milli-g
•
Once per 5 years event = 19 milli-g
With minimum damping ratio of 1.5% (refer to DPT 1311 section 3.5)
According to the DPT Standard 1311-50 [5], the recommended serviceability design for human comfort criteria for the studied building is that the peak acceleration under a 10 year return period should be less than 15 mg and 25 mg for residential buildings and commercial buildings, respectively. To verify the building under human comfort, the results from the ETABS model will be sent to a wind engineer, Dr. Nakorn, to asses the building accelerations by using the existing wind tunnel results. By following this procedure it will provide clear information on occupant comfort.
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8.4
Lateral stability
The initial lateral stability system in the tower comprises a centrally located reinforced concrete core. The shape of the core has been dictated by the shape of the floor plate and the location the lifts required to service all floors. The building has a pixilation effect along its height and the core is setback at two locations up the tower.
The structural arrangement for an outrigger system consists of a main core connected to exterior columns by relatively stiff horizontal members commonly referred to as outriggers. The way in which the outriggers operate is that when the building is subjected to lateral loads, the column restrained outriggers resist the rotation of the core, causing the lateral deflections and moments to be smaller than if the freestanding core alone resisted the loading. The moment is now resisted not by bending of the core alone, but also by the axial tension and compression of the exterior columns connected to the outriggers. As a result the effective depth of the structure is increased when it flexes as a vertical cantilever, by the development of tension in the windward columns, and by compression in the leeward columns.
8.5
Building behavior
The behavior of the building for the structural arrangement under the combined effect of the loading conditions (gravity and lateral loads) is explained below:
8.5.1 Serviceability In all tall structures it is imperative that the lateral stability system used ensures that the deflections along the height of the tower are kept within codal serviceability limits. The profile which the core wall steps in at 2 locations up the eight of the building in the y-direction dictates that it is the building drift in the same direction which will govern the serviceability design.
In order to control the drift in the y-direction the lateral stability is provided by the central core and the three outrigger levels, which also forms the stability system in the x-direction. The lateral stability system ensures the drift in both x and y-directions are kept within the limits.
The dynamic analysis of the structure has been carried out and is included in the ETABS threedimensional finite element model. Figure 8.1 and 8.2 shows the parameters considered in dynamic analysis. The response spectrum analysis uses dynamic characteristics of the building which in turn can be expressed through the mode shapes. As the structure is located in a low-seismic area, the results of the dynamic responses are not utilized in load combinations directly, but the responses of the dynamic analysis including model mass participation, mode frequency and etc, are submitted to the wind tunnel testing consultant to cater for the dynamic response of the structure under wind loads. The results from the wind tunnel testing including the effect of dynamic analysis are obtained and utilized for design.
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Figure 8.1 Dynamic analysis: Eigenvectors analysis is carried out in ETABS to determine the different modes shapes of the tower.
Figure 8.2 The P-Delta effects are included in the ETABS model to capture the secondary effects on the frame elements. Figure 8.2 shows the relevant P-Delta parameters used in design of the elements.
Refer to Appendix E for the 12 mode shapes as highlighted in figure 8.1
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8.6
Modeling and Analysis
In order to analyze the lateral stability of the Tower, ETABS software has been used to accurately model the structure and apply the different loading conditions.
In order to ensure the results from all software models are accurate the results have been checked with hand calculations, use of in-house spreadsheets and simpler software packages, where possible.
The model will provide the following: Building response analysis •
Modal Analysis Summary
•
Global reaction
•
Building Time Period & Frequencies
•
Building Mode Shape Plots
•
Modal participating ratios
•
Storey shears and overturning moments
•
Storey displacements
•
Storey Drifts
Long term analysis and design •
Columns differential shortening
•
Long term horizontal deformations
•
Creep
•
Shrinkage
•
Settlements
After completing the analysis of the building, sizing the members and reinforcement can be defined for the following: •
Core wall
•
Mega columns
•
Mat foundations
•
Retaining structure
•
Slabs and beams
•
Post tension
•
Outrigger floor
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9
O PERATIONAL AND P ERFORMANCE R EQUIREMENTS
The I-modifier (I=sectional moment of inertia) values provided (seen in table 9.1) were the starting values for an interactive analysis. These values are refined after initial analysis to suit the level of stress related cracking that can be anticipated for each limit state. Note that the wind forces from the wind tunnel tests are calculated using the natural frequency and the mode shape generated by the dynamic analysis. Therefore superior dynamic response resulting from higher stiffness will result in lower wind forces and consequently design force effects. A rational assessment in this way will result in optimum reinforcement. The secant modulus will form the bases of the rational assessment. The assumption of a higher degree of cracking can be adopted without a rational analysis in which case the wind forces will need to relate to the appropriate stiffness model that has been assumed. The appropriate practice is to separate the strength models for wind and seismic where the 2500 year return period seismic response results in the formation of plastic hinges, yielding and a higher degree of cracking than that for ultimate wind where the structure responds elastically. The CTBUH/ASCE07-05 design intent for the 2500 yr return seismic effects is "to resist with damage but without collapsing". Therefore it would be unrealistic for the structure to perform similar to ultimate wind at this threshold.
The modulus of elasticity or “Young’s Modulus” is defined as the slope of the stress-strain curve within the proportional limit of a material. For a concrete material, the secant modulus is defined as the slope of the straight line drawn from the origin of axes to the stress-strain curve at the compressive stress of 0.45 fc’ as stated in ACI318-99 section 8.5.1. This is the value most commonly used in structural design.
Figure 9.1 Secant modulus
Note: 50yr return seismic and 10 yr return wind result in very low force effects and the material response in this case with it associated low damping ratio will be dynamic (tangent modulus for concrete). From the figure we can see that the secant modulus is almost same to the tangent modulus obtained at some lower percentage of the ultimate strength.
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Table 9.1 ETABS models used for analysis of the building Model
Elastic Modulus
Reduction Factor for Seismic Load _(R)
I-Modifier
Wind load
Seismic load
Damping Ratio 1.5% (refer to DPT 1311-50 section 3.5) 1.5%
2
2.0%
4 or higher
Comfort and performance (Refer to appendix C)
E= 1.15Esecant
As per ACI section 10.11 (reference to R10.11.1)
10 yrs return period
50 yrs return period
Wind Ultimate (Refer to appendix B)
E = Esecant
As per ACI section 10.11 (reference to R10.11.1)
50 yrs return period
-
Seismic Ultimate (Refer to appendix A)
E = Esecant
As per ACI section 10.11 (reference to R10.11.1)
-
2500 yrs return period
-
To assign “cracked” or “uncracked” condition to the shear-walls should be in accordance with R10.11.1/ACI318-99, stating: “If the factored moments and shears form an analysis based on the moment of inertia of wall taken equal to 0.70Ig indicate that wall will crack in flexure, based on the modulus of rupture, the analysis should be repeated with I = 0.354Ig in those stories where cracking is predicted at factored loads.” “Analyses of deflections, vibrations, and building periods are needed at various service load levels to determine the serviceability of the structure and to estimate the wind forces in wind tunnel laboratories. The seismic base shear is also based on the service load periods of vibration. The magnified service loads and deflections by a second-order analysis should also be computed using service loads. The moments of inertia of the structural members in the service load analyses should, therefore, be representative of the degree of cracking at the various service load levels investigated. Unless a more accurate estimate of the degree of cracking at design service load level is available, it is satisfactory to use 1/0.7 = 1.43 times the moments of inertia given in 10.11.1 for service load analyses.”
An alternative process could be to take internal pier forces from ETABS and calculate stresses using standard rectangular concrete section procedure including the effect of the reinforcement.
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10
C ONSTRUCTION
The contractor is responsible for submitting method statements to the engineer for approval for all elements of the work. These method statements will provide details of the proposed construction sequences.
In order to meet client deadlines a design schedule is needed to be submitted for mutual agreement. Along with the programme the contractor must treat the construction of the Tower as the critical path item.
11
C ONSTRUCTION M ATERIALS AND P ROPERTIES
This section includes design strengths and applicable specifications of the main structural materials used in the design and construction of the building. The material strengths and specifications are as follows: Table 11.1 Concrete Strength Components
Concrete Grade
Mega Columns / Core wall
Level B1 – 30
fc’: 600 ksc
Level 31 – 40
fc’: 500 ksc
Level 41 – 73
fc’: 400 ksc
Floor slabs
fc’: 280 ksc – 350 ksc
Mat foundations
fc’: 280 ksc – 350 ksc
It is anticipated that a dedicated concrete batching plan will need to be set up to achieve the required quality, quantity and strength of concrete for all structural elements.
Table 11.2 Steel Reinforcement Properties Reinforcing Bar
Description
Yield Strength
Diameter
Deformed Bars
ASTM A615, Grade 60 or TIS 24-2527 deformed high yield steel bars
SD 40 – fy ≥ 4,000 kg / cm2
12, 16 and 20 mm
SD 50 – fy ≥ 5,000 kg /
25 mm and higher
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cm2
Round Bars
Wire mesh
Specified Yield Strength of round bar in ASTM A615 Gr.40, TIS 20-2527 SR 24 Specified yield strength of wire mesh
fy ≥2,400 kg / cm2
6 and 9 mm
fy ≥ 5550 kg / cm2
N/A
Table 11.3 Structural Steel
12
Materials
Description
Yield Strength
Steel
Specified Minimum Yield Stress of Steel in A36, JIS G3101 SS400 or equivalent
fy = 2,400 kg / cm2
Welding Electrode
AWS A5.1 E70XX, JIS Z3211 or equivalent
N/A
High Strength Bolt
ASTM A325, JIS B1186 - F8T or equivalent
N/A
Anchor Bolt
ASTM A307 Gr.B, JIS G3101 SS400 or equivalent
N/A
N UMBERING S YSTEM
This project adheres to a project wide document numbering convention. All documents created on the project must be numbered in accordance with the numbering convention defined in Figure 12.1
Figure 12.1 Numbering System used in the design drawings
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13
A PPENDIX A – E XTRACT FROM PUBLISHED LITERATURE THAT COMPARES OTHER RECOMMENDED METHODS INCLUDING ASCE
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14
A PPENDIX B – C ALCUL ATION OF WIND FORCES FOR STRENGTH DESIGN FROM WIND TUNNEL TEST
To determine the wind forces for strength design and comfort criteria based on acceleration which will be adopted for MahNakhon project, has to be taken from the full ETABS model of the building. The results of the model will be given to the Wind Engineering Consultant who is responsible for the evaluation of building accelerations using the output from the wind studies that have been carried out in the model and in collaboration with the consultant. Refer to the Wind Tunnel Test report from Civil Park International and TU-AIT WT Lab Bangkok, March 2009, chapter 4. The example below provides a comparative study of the calculation of wind forces by evaluating the output of wind tunnel studies for a typical tall building for illustration purposes only. Note that three sets of frequencies comprising Analytical, Analytical minus 10% and Analytical plus 10% are used for the sensitivity study at 3 different damping levels. In this example for strength design the forces derived from the analysed value of the frequency with 2% damping has been adopted for the design. The tables and the graphs below show the results of the evaluation and the recommended directional magnitudes and combinations provided by the wind engineers. Table 14.1 – Summary of predicted pear overall structural wind loads. Analysis Configuration
Periods (sec)
Damping (% of Mode Mode Mode Critical) 1 2 3
Moments My (Nm)
Mx (Nm)
Shear Mz (Nm)
Fx (N)
Fy (N)
1
9.27
8.48
2.11
2.0%
1.16E+10 1.53E+10 2.66E+08 3.64E+07 4.92E+07
2
10.30
9.43
2.35
2.0%
1.29E+10 1.91E+10 2.70E+08 4.03E+07 6.03E+07
3
11.33
10.37
2.58
2.0%
1.63E+10 2.34E+10 2.69E+08 5.02E+07 7.41E+07
4
9.27
8.48
2.11
1.5%
1.26E+10 1.68E+10 2.70E+08 3.94E+07 5.40E+07
5
10.30
9.43
2.35
1.5%
1.41E+10 2.13E+10 2.76E+08 4.40E+07 6.67E+07
6
11.33
10.37
2.58
1.5%
1.83E+10 2.64E+10 2.74E+08 5.62E+07 8.90E+07
7
9.27
8.48
2.11
2.5%
1.09E+10 1.45E+10 2.63 +08
8
10.30
9.43
2.35
2.5%
1.20E+10 1.77E+10 2.67E+08 3.78E+07 5.56E+07
9
11.33
10.37
2.58
2.5%
1.50E+10 2.15E+10 2.66E+08 4.61E+07 6.80E+07
3.48E+07 4.61E+07
Note: This is an example to illustrate the method for a sensitivity analysis.
For this project, the analysis needs to consider the total response to wind of the MahaNakhon building, it necessary to combine the individual responses. A conservative approach would be to simply add in vertical form of the individual components e.g. Mx, My and Mz for 36 wind directions. The numbers of load cases are kept to a minimum by considering the high wind load direction. For natural frequency fo, damping ration = 0.02, the recommended load combinations for studied building are shown in the table 14.2.
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Table 14.2 – Recommended wind load combinations factors intermediate properties, 2% damping Direction (degree)
Equivalent Incoming Wind Direction (Parallel)
Load Combination
My
Mx
Mz
(MN-m)
(MN-m)
(MN-m)
-1
-1
(%)-1
(%)
(%)
-2,408
-1,324
18
(-59 )
( 40 )
( 26 )
-1,678
-3,271
23
(-41 )
( 100 )
( 34 )
-1,678
-1,811
40
( -41 )
( 55 )
( 59 )
1,656
-3,066
-20
( 41 )
( 94 )
(-30 )
4,047
-2,019
-26
( 100 )
( 62 )
(-39 )
2,254
-2,019
-45
( 56 )
( 62 )
(-67 )
2,373
1,345
13
( 59 )
(-41 )
( 20 )
1,620
3,180
18
( 40 )
(-97 )
( 27 )
1,620
1,804
33
1
0
X
2
3
4
90
Y
5
6
7
180
X
8
9 ( 40 )
( -55 )
( 48 )
2,496
1,664
21
( 62 )
(- 51 )
( 30 )
1,593
734
24
( 39 )
(-84 )
( 36 )
1,593
1,932
36
( 39 )
(-59)
( 53 )
1,406
2,544
40
( 35 )
(-78 )
( 60 )
3,104
1,758
46
( 77 )
(-54 )
( 68 )
1,871
1,758
63
( 46 )
(-54 )
( 93 )
10
230
X
11
12
13
280
Y
14
15
1,265
2,401
48
( 31 )
(-73 )
( 71 )
16
290
Y
2,855
1,670
53
( 71 )
(-51 )
( 78 )
1,693
1,670
68
( 42 )
(-51 )
(100)
17
18
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Note: The combinations will be refined through considerations of the structure’s response to various wind directions, modal coupling, and correlations of wind gusts and directionality of strong winds in the local wind climate.
Below shows examples of typical directional wind forces based on sample values from the sensitivity analysis, they are only for illustrating the method to be used for MahaNakhon in collaboration with the wind engineer.
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The following figures show coefficients and acceleration responses that was used in the analysis.
Figure 14.1 Mean Wind Force Coefficients along Each Axis
Figure 14.2 Standard Deviation of Fluctuating Base Moments and Torques about each Axis
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Figure 14.3 Comparison of predicted maximum peak total lateral acceleration responses for two values of return periods of V5 and V10, and four values of damping ratios (natural frequencies 0.8 f0
Figure 14.4 Comparison of predicted maximum peak total lateral acceleration responses for two values of return periods of V5 and V10, and four values of damping ratios (natural frequencies f0
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15
A PPENDIX C – C OMPARISON OF OCCUPANCY COMFORT CRITERIA ( CASE STUDY )
The graphical illustrations in this section show a comparison of the acceleration response and comfort criteria that was assessed for the tall building at various floor levels in relation to ISO, CTBUH, RWDI (Residential) and the AIJ. In this case the study was carried out in relation to 1% and 1.5% damping. The following damping levels were considered as reasonable for strength design and performance assessment for this particular tall building under the action of wind forces.
•
Strength Design
•
Serviceability (Deflection) 1.5%
•
Acceleration Perception
2.0%
1.0%
These values are considered compatible with the assessment threshold for wind effects for strength, serviceability and acceleration. However there are instances in the past when higher values of damping have been used for assessment of acceleration perception and evidence of satisfactory performance by such buildings.
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16
A PPENDIX D – L OAD C OMBINATION ( FULL )
Case
Load Combinations
WU001
1.4 DEAD + 1.4 SDL
WU002
1.4 DEAD + 1.4 SDL + 1.7 LIVE + 1.7 LLT
WU003
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL00C1
WU004
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL00C2
WU005
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL00C3
WU006
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL90C1
WU007
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL90C2
WU008
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL90C3
WU009
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL180C1
WU010
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL180C2
WU011
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL180C3
WU012
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL230C1
WU013
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL230C2
WU014
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL230C3
WU015
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL280C1
WU016
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL280C2
WU017
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL280C3
WU018
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL290C1
WU019
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL290C2
WU020
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT + 1.275 WL290C3
WU021
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL00C1
WU022
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL00C2
WU023
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL00C3
WU024
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL90C1
WU025
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL90C2
WU026
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL90C3
WU027
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL180C1
WU028
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL180C2
WU029
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL180C3
WU030
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL230C1
WU031
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL230C2
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WU032
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL230C3
WU033
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL280C1
WU034
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL280C2
WU035
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL280C3
WU036
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL290C1
WU037
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL290C2
WU038
1.05 DEAD + 1.05 SDL + 1.275 LIVE + 1.275 LLT - 1.275 WL290C3
WU039
0.9 DEAD + 0.9 SDL + 1.3 WL00C1
WU040
0.9 DEAD + 0.9 SDL + 1.3 WL00C2
WU041
0.9 DEAD + 0.9 SDL + 1.3 WL00C3
WU042
0.9 DEAD + 0.9 SDL + 1.3 WL90C1
WU043
0.9 DEAD + 0.9 SDL + 1.3 WL90C2
WU044
0.9 DEAD + 0.9 SDL + 1.3 WL90C3
WU045
0.9 DEAD + 0.9 SDL + 1.3 WL180C1
WU046
0.9 DEAD + 0.9 SDL + 1.3 WL180C2
WU047
0.9 DEAD + 0.9 SDL + 1.3 WL180C3
WU048
0.9 DEAD + 0.9 SDL + 1.3 WL230C1
WU049
0.9 DEAD + 0.9 SDL + 1.3 WL230C2
WU050
0.9 DEAD + 0.9 SDL + 1.3 WL230C3
WU051
0.9 DEAD + 0.9 SDL + 1.3 WL280C1
WU052
0.9 DEAD + 0.9 SDL + 1.3 WL280C2
WU053
0.9 DEAD + 0.9 SDL + 1.3 WL280C3
WU054
0.9 DEAD + 0.9 SDL + 1.3 WL290C1
WU055
0.9 DEAD + 0.9 SDL + 1.3 WL290C2
WU056
0.9 DEAD + 0.9 SDL + 1.3 WL290C3
WU057
0.9 DEAD + 0.9 SDL - 1.3 WL00C1
WU058
0.9 DEAD + 0.9 SDL - 1.3 WL00C2
WU059
0.9 DEAD + 0.9 SDL - 1.3 WL00C3
WU060
0.9 DEAD + 0.9 SDL - 1.3 WL90C1
WU061
0.9 DEAD + 0.9 SDL - 1.3 WL90C2
WU062
0.9 DEAD + 0.9 SDL - 1.3 WL90C3
WU063
0.9 DEAD + 0.9 SDL - 1.3 WL180C1
WU064
0.9 DEAD + 0.9 SDL - 1.3 WL180C2
WU065
0.9 DEAD + 0.9 SDL - 1.3 WL180C3
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WU066
0.9 DEAD + 0.9 SDL - 1.3 WL230C1
WU067
0.9 DEAD + 0.9 SDL - 1.3 WL230C2
WU068
0.9 DEAD + 0.9 SDL - 1.3 WL230C3
WU069
0.9 DEAD + 0.9 SDL - 1.3 WL280C1
WU070
0.9 DEAD + 0.9 SDL - 1.3 WL280C2
WU071
0.9 DEAD + 0.9 SDL - 1.3 WL280C3
WU072
0.9 DEAD + 0.9 SDL - 1.3 WL290C1
WU073
0.9 DEAD + 0.9 SDL - 1.3 WL290C2
WU074
0.9 DEAD + 0.9 SDL - 1.3 WL290C3
Case
Load Combinations
EU001
1.4 DEAD + 1.4 SDL
EU002
1.4 DEAD + 1.4 SDL + 1.7 LIVE + 1.7 LLT
EU003
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT + 1.403 EX
EU004
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT + 1.403 EY
EU005
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT + 1.403 EX30EY
EU006
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT + 1.403 30EXEY
EU007
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT - 1.403 EX
EU008
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT - 1.403 EY
EU009
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT - 1.403 EX30EY
EU010
1.103 DEAD + 1.103 SDL + 1.275 LIVE + 1.275 LLT - 1.403 30EXEY
EU011
0.847 DEAD + 0.847 SDL + 1.43 EX
EU012
0.847 DEAD + 0.847 SDL + 1.43 EY
EU013
0.847 DEAD + 0.847 SDL + 1.43 EX30EY
EU014
0.847 DEAD + 0.847 SDL + 1.43 30EXEY
EU015
0.847 DEAD + 0.847 SDL - 1.43 EX
EU016
0.847 DEAD + 0.847 SDL - 1.43 EY
EU017
0.847 DEAD + 0.847 SDL - 1.43 EX30EY
EU018
0.847 DEAD + 0.847 SDL - 1.43 30EXEY
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A PPENDIX E – 12 MODE SHAPES
Mode 2 – 7.47 seconds
Mode 1 – 7.96 seconds
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Mode 3 – 2.02 Seconds
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Mode 4 – 1.98 seconds
80
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Mode 6 – 1.58 seconds
Mode 5 – 1.70 seconds
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81
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Mode 7 – 1.55 seconds
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Mode 8 – 1.57 seconds
82
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Mode 9 – 0.95 seconds
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Mode 10 – 0.83
83
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Mode 11 – 0.82 seconds
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Mode 12 – 0.77 seconds
84
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18
APPENDIX F – WIND LOAD GRAPHS FOR 10 YEARS AND 50 YEARS (UNIFORM MASS)
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