TITLE PAGE
Civil Design Basis
Contents
Chapter
Title
1.
Introduction
2.
General
3.
Codes and Standards
4.
Material Specification
5.
Loads
6.
Environmental Conditions
7.
Load Combinations
8.
Analysis
9.
Nominal Cover to Reinforcement Including Links
10.
Method of Design
11.
Design Basis
12.
Roads and Paving
13.
Design of Masonry works
Page
Civil Design Basis
1.
Introduction
This document forms the Engineering Design Basis for Civil & Structural Works. The contents of these documents form the guideline for engineering and to provide information to the other disciplines concerned.
2.
General
2.1
Customer
:
2.2
Plant
:
2.3
Location
:
3.
Codes and Standards
3.1
Brick, Hollow Block and Bituminous Compounds
IS-1077 : 1992
:
Common burnt clay building bricks
IS-2212 : 1991
:
Brick work
IS-4860 : 1968
:
Acid Resistant Bricks
IS-2185 Part I : 2005
: :
Cement Concrete Block Hollow and Solid Concrete Blocks
Part II : 1983
:
Hollow and solid light weight concrete blocks
Part III : 1984
:
Autoclaved cellular Aerated concrete blocks
IS-4457 : 1982
:
Ceramic Unglazed Vitreous Acid Resisting Tiles
IS-1346 : 1991
:
Water Proofing of Roof using Bitumen felts
IS-1580 : 1991
:
Bituminous Compounds for waterproofing and caulking purposes
IS-4365 : 1967
:
Application of Bitumen Mastic
IS-7198 : 1974
:
Damp proofing using bitumen felts
IS-9510 : 1980
:
Bitumen Mastic - A.R. Grade
3.2
Cement and Fine & Coarse Aggregates
Civil Design Basis IS-12269 : 1987
:
53 grade Ordinary Portland Cement (OPC) IS-
455 : 1989
:
Portland Slag Cement
Part I
:
Portland Pozzolana Cement (PPC) fly ash based
Part II
:
PPC Calcined clay based.
IS-8112 : 1989
:
43 grade Ordinary Portland Cement (OPC) IS-
12330 : 1988
:
Sulphate Resisting Portland Cement
IS-383 : 1970
:
Coarse and Fine aggregate
IS-456 : 2000
:
Plain and Reinforced Concrete
IS-458 : 1988
:
Pre-cast concrete pipes
IS-2645 : 1975
:
Integral cement waterproofing compounds
:
Design of Liquid retaining structures
IS-4971 : 1968
:
Industrial floor finishes
IS-4990 : 1993
:
Plywood for concrete shuttering work
IS-1893 - Part I : 2002
:
Earthquake resistant design of structures
IS-4326 : 1993
:
Code of practice for earthquake resistant design & construction of building.
IS-13920 : 1993
:
Ductility detailing of RCC Structure subjected to seismic forces
IS-800 : 1984
:
General Construction in Steel.
IS-806 : 1968
:
Use of Steel tubes in general building construction.
IS-1489 : 1991
3.3
Concrete Design
IS-3370 Part I : 2009 Part II : 2009 Part III : 1967 Part IV : 1967
3.4
Steel Design
IS-1363 : 2002
Hexagon Head Bolts, Screws and Nuts of Product Grade `C' Part I : Hexagon Head Bolts (Size Range M 5 to M 64)
Part II
Hexagon Head Screws (Size Range M 5 to M 64) Part
III
Hexagon Nuts (Size Range M 5 to M 64)
IS-1364 : 2002
Part I
:
Hexagon Head Bolts, Screws and Nuts of Product Grades A and B Hexagon Head Bolts (Size Range M 1.6 to M 64) Part II Hexagon Head Screws (Size Range M 1.6 to M 64) Part III
Civil Design Basis Hexagon Nuts, Style 1 (Size Range M 1.6 to M 64) Part IV
Hexagon Thin Nuts (Chamfered) (Size Range M1.6 to M64)
Part V
Hexagon Thin Nuts - Product Grade B (Unchamfered) (Size Range M 1.6 to M 10)
Part VI
Hexagon Nuts, Style 2
IS-2062 : 2006
:
Steel for general structural purpose IS-
4000 : 1992
:
High strength bolt in steel structures IS-
5624 : 1993
:
Foundation Bolts
IS-1080 : 1985
:
Design and Construction of shallow foundation on soils
IS-6403 : 1981
:
Determination of bearing capacity on shallow foundations.
IS-8009
:
Code of Practice for Calculation of Settlements of Foundations
3.5
Foundation Engineering
Part I : 1976
Shallow Foundations Subjected to Symmetrical Static Vertical Loads
Part II : 1980
Deep Foundations Subjected to Symmetrical Static Vertical Loading
IS-2911 Part I:1979
Design and Construction of Pile Foundation in-Situ Piles)
IS-2911 Part IV :1985
Load Test on Piles.
3.6
(Bored Cast
Reinf orcement
IS-1786 : 1985
:
High strength deformed steel bars
IS-2502 : 1963
:
Bending and fixing of bars for concrete reinforcement
IS-5525 : 1969
:
Recommendation for detailing of reinforcement in concrete works.
:
Code of practice for Design loads.
3.7
Loading Standards
IS-875 Part I to V : 1987 IS15498 : 2004
3.8
Guidelines for improving the cyclonic resistance of low rise buildings and other Buildings and Structures
:
Design Aids
SP-7 : 1983
:
National Building Code of India
SP-16 : 1980
:
Design aids for Reinforced Concrete to IS-456
SP-34 : 1987
:
Handbook on concrete reinforcement and detailing
SP-38
:
Handbook of typified design for structures with steel roof trusses.
Civil Design Basis 3.9
IRC - Code
IRC:6 : 2000
:
Loading
IRC:15 : 2002
:
Code of practice for construction of RCC Paving.
IRC:58 : 1988
:
Design of Rigid pavement for Highway.
Latest revisions of IS codes will b e used for engineering purpose.
4.
Material Specification
4.1
Minimum Concrete Grade
Footing / Equipment foundation/Piles/Pile Caps
fc :
M-30
Plinth beams / Cable trenches
fc :
M-25
Super structure
fc :
M-25
Water retaining structure
fc :
M-30
Grade slabs
fc :
M-25
PCC for wall footing
fc :
M-10
Lean concrete below RCC Footings (100 mm thickness)
fc :
M-10
fy :
415 N/mm² & 500 N/mm²
fy :
250 N/mm
4.2
Reinf orcement Bars
High tensile bars conforming to IS 1786
4.3
Structural Steel
Structural steel
4.4
2
Cement
Sulphate Resistant cement shall be used for sub-structure & Ordinary Portland cement shall be used for super structure.
Civil Design Basis
5.
Loads
5.1
Dead Load
Plain concrete
:
24 kN/cu.m.
Reinforced cement concrete with normal aggregate
:
25 kN/cu.m.
Brick walls with plaster
:
22 kN/cu.m.
Aerated concrete blocks
:
10 kN/cu.m.
Solid concrete block with plaster
:
24 kN/cu.m.
Structural steel / cheq. plate/grating
:
78.5 kN/cu.m.
Rubble masonry
:
26 kN/cu.m.
Cement Mortar / concrete screed 100mm thick over floors
:
2.4 kN/sq.m.
Cement based water proofing over roof slab avg. 150 thk including brickbat coba.
:
3.5 kN/sq.m.
Floor finish up to 50mm thick
:
1.25kN/sq.m.
G.I Sheet roofing
:
0.13 kN/sq.m.
AC Sheet roofing
:
0.12 kN/sq.m.
False Celing ( including mechanical / Electric cables in Office areas) Toilets (European Water Closets are considered) raised by 200 mm.
:
1.0 kN/Sq.m ( Can be taken as nil if Live load is taken as 5.0kN/m2) 0.2 * 19.2 = 3.84 kN/m² ~ 3.90 kN/m ²
:
Civil Design Basis 5.2
Live Load
Add floor wise live load as per IS 875.
Apart from the specified live load, any other equipment load or the actual loads of the equipment/panels or weight of contents/water inside equipment/vessel or possible overloading during construction/maintenance shall also be considered in the design. 5.3
Impact & Vibratory Load s
5.4
Traffic
Load
Roads / culverts on trenches across roads
: :
IRC Class - AA Loading Precast cover
IRC Class - AA Loading Trench and pit covers
installed flush with paving shall be designed for wheel load as above.
5.5
Other Loads
Any other relevant stresses imparted to the structure due to variation in daily and seasonal temperature, water table, erection and maintenance loads, creep, shrinkage etc. considered as applicable.
6.
Environmental Conditions
6.1
Rainfall
Maximum annual rainfall
:
1000 mm
Maximum rainfall in 24 hrs.
:
400 mm
Maximum Intensity of rainfall (For SW Drain Design)
:
100 mm/hr.
6.2
Exposure Condition
6.3
Wind (As per IS-875
:
Moderate (As per Clause No. 8.2.2 of IS 456)
Location
:
Basic wind speed
:
Risk coefficient (k1)
:
Terrain, Height & Structural Size factor (k2)
:
Civil Design Basis Topography Factor (k3)
:
Cyclonic factor
:
Earthquake (As per IS: 1893)
6.4
Zone
:
The design horizontal seismic coefficient Ah shall be as follows: Ah :
Where
Z
= I
=
R
=
Sa
=
g
Civil Design Basis
7.
Load Combinations
7.1
Load combination for design of steel structures (Working stress method)
7.2
7.1.1
1.0DL + 1.0LL
7.1.2
1.0DL + 1.0LL ± 1.0WLx
7.1.3
1.0DL + 1.0LL ± 1.0WLz
7.1.4
1.0DL ± 1.0WLx
7.1.5
1.0DL ± 1.0WLz
7.1.6
1.0DL + 1.0LL ± 1.0ELx
7.1.7
1.0DL + 1.0LL ± 1.0ELz
7.1.8
1.0DL ± 1.0ELx
7.1.9
1.0DL ± 1.0ELz
Load combination for design of RCC structures (Limit state)
7.2.1
1.5DL + 1.5LL
7.2.2
1.2DL + 1.2LL ± 1.2WLx
7.2.3
1.2DL + 1.2LL ± 1.2WLz
7.2.4
1.5DL ± 1.5WLx
7.2.5
1.5DL ± 1.5WLz
7.2.6
1.2DL + 1.2LL ± 1.2ELx
7.2.7
1.2DL + 1.2LL ± 1.2ELz
7.2.8
1.5DL ± 1.5ELx
7.2.9
1.5DL ± 1.5ELz
7.2.10
0.9DL ± 1.5ELx
7.2.11
0.9DL ± 1.5ELz
Civil Design Basis 7.2.12
0.9DL ± 1.5WLx
7.2.13
0.9DL ± 1.5WLz ( X & Z denotes horizontal directions)
8.
Analysis All structures are analysed by stiffness method using Staad Pro software package.
9.
9.1
Nominal Cover to Reinforcement Including Links Footing
Pile Foundation
:
Bottom
:
50 mm
:
Sides
:
50mm
:
Pile
:
50mm
:
Pile cap
:
50mm
9.2
Columns & Pedestals
:
Sides
:
40 mm
9.3
Beam
:
Bottom
:
30 mm
:
Top
:
30 mm
:
Sides
:
30 mm
9.4
Slab
:
Bottom / Top
:
25 mm ( Table-16 Note-2 IS456 :2000)
9.5
For water retaining structure
:
Bottom Raft
:
50 mm (Bottom)
Wall contact with soil face
:
50 mm
Wall contact with liquid face
:
30 mm
Top Slab
:
30 mm (Bottom)
35mm (top) ( Table-16 Note-2 IS-456 :2000)
Civil Design Basis
10. Method of Design RCC footings ,Piles & Pile Caps
:
Limit state Design
RCC columns
:
Limit State Design
RCC floor beams/tie beam, slabs and Walls
:
Limit State Design
Equipment foundation.
:
Limit state Design
Structural steel columns and beams
:
Working stress Roof
trusses
:
Working stress
RCC water retaining structures
:
Working Stress with Uncracked sections
Retaining walls
:
Working stress
11. Design Basis 11.1
Foundations
11.1.1
Net safe bearing capacity of soil
11.1.2
Types of Foundation For buildings and structures For equipment’s
:
As per Geotechnical Report
: :
Pile foundation / Isolated spread foundation Pile foundation / Isolated spread foundation
Boundary Wall 11.1.3
11.1.4
11.1.5
Open foundation
Allowable increase in soil bearing capacity in event of - Wind
:
25%
- Earthquake
:
25%
- Overturning
:
1.4
- Sliding
:
1.4
- Buoyancy
:
1.1
Factor of safety against
As a general rule following features will be adopted, unless decided otherwise in a specific or exceptional case: 11.1.5.1
Top of footing will be horizontal and flat.
11.1.5.2
Minimum depth of footings shall be as s per Geotechnical Report
11.1.6 Pile Load Capacities
Civil Design Basis 11.1.6.1 Bored cast-in-situ piles Load carrying Capacity of Bored cast-in-situ piles shall be as per Geotechnical report based on location of pile.
11.2 11.2.1
11.2.2
Pipe racks Materials of Construction 11.2.1.1
Pile foundations and column/pedestals
11.2.1.2
RCC for pipe sleepers
11.2.1.3
Steel for superstructure
Loads 11.2.2.1
Vertical Load Vertical load due to piping and cables shall be assumed as per data provided by the piping, electrical and instrumentation departments after due study and discussions and shall be considered as a part of dead load.
11.2.2.2
Longitudinal forces Frictional forces shall be assumed as 0.15 times the maximum operating vertical loads. Wind loads shall be calculated as per IS: 875.
11.2.2.3
Lateral / Transverse forces Lateral anchor forces shall be assumed as per data provided by the piping department. Lateral wind forces shall be estimated as per IS: 875.
11.2.2.4
All the foundation and independent supporting structure for vibrating machines shall be design in accordance with IS:2974
11.3
Liquid Retaining Structures
11.3.1
Allowable stress in concrete for un cracked section for M30 grade in Direct Tension ( σst)1.5 N/Sq.mm & 2.0 N/Sq.mm Tension due to bending ( σcbt)
11.3.2
Allowable stress in steel Fe 415 = 130 N/sq.mm. (For Tensile stress in member Under direct Tension ,Bending & Shear ) & 140 N/sq.mm. (Compressive stress in column under subjected to direct load) As per IS-3370:2009 Part -2 Table-4 ).
11.4
Storm Water Drain
Storm water drain shall be designed for a maximum rainfall intensity of 100 mm/hr.
11.4.1
Surface runoff
Qr =
Where: 3
11.4.1.1
R = Maximum Rainfall intensity in mm /hr P = Run off co-efficient A = Catchment area in sq.m. Run off co-efficient for various surfaces are as follows : For building roof
: 1.0
P x R x A cu.m/sec. 3600 x 1000
Civil Design Basis
11.4.1.2
For paved areas
: 1.0
For roads and drains
: 1.0
For paved areas
: 0.8
For undeveloped areas
: 0.6
Minimum Velocity for Drain design: 0.6m/s Maximum velocity for Drain Design : 2.4m/s Minimum width of the drain shall be 300mm
All RC hume pipe crossing the roads for storm water drainage shall be NP3 Class pipes conforming to IS 458
Steel Structures
11.5
All structural steel work such as Design, fabrication and erection shall be carried out in accordance with IS 800, IS 806, IS 814 & IS 816,IS 2062.
11.5.1
Permissible Stresses (i)
Permissible stresses in structural members shall be as per IS 800-1984, IS 801, & IS 806. (ii) Permissible stresses in bolts shall be as per IS 800-1984 & IS 801
(iii)
11.5.2
Permissible stresses in welds shall be as per IS 816, IS 814 & IS 801.
Permissible Vertical Deflection: Shall be:
(i)
Gantry girder for electric overhead crane (up to 50T capacity)
- Span/750
(ii)
Gantry girder for electric overhead crane (over 50T capacity)
- Span/1000
(iii)
Gantry girder for manually operated crane
- Span/500
(iv)
Girder/ Beam for supporting dynamic equipment/hoist
(v)
Grating/ Chequered plate ( Two way)
(vi)
Purlins & Girts for Live Load/ Wind Load (elastic cladding)
(vii)
Rafter supporting Profiled Metal Sheeting under Live load /wind load – Span / 180
11..5.3
Span/450 - Short Span/300 - Span/150
(Table 13.6 Arya Azmani) IS:800 -2007 (Table-6) IS:800 -2007 (Table-6)
Permissible Horizontal Deflection: Shall be height/325 for multi-storeyed structure/building. All the structural steel will be painted with one coat of red oxide paint and two coats of superior quality synthetic enamel paint. Cold rolled sections will be painted with Zinc chromate red oxide paint and two coats of superior quality synthetic enamel paint. (One coat before erection and another coat after erection at site ).
11.6
Criteria for Expansion Joint
For R.C.C Structure: - IS: 456-2000 Cl 27.2 ( At Expansion joint twin column with column on common footing ) For Steel Structure: - IS: 875-1984 Cl 3.14
For Liquid Retaining Structures: - IS: 3370-2009 Cl 10
Civil Design Basis
12. Roads and Paving
12.1
Normally all roads shall be asphalted (bitumen macadam) over W.B.M layer on suitable sub base. Main roads shall be 6.0m wide
12.2
All paved areas shall be in concrete mix M15(1:2:4) with suitable base course.
12.3
All drain to be in masonry with open top.
13. Design of Masonry works
13.1
All masonry works shall be designed in accordance with IS 1905, IS 2212, IS 1077 IS 1597 & IS 4326
13.2
All brick masonry walls shall be built with 1st class good quality Bricks having minimum crushing strength of each unit not be less than 3.5 kN/mm2, in cem ent mortar 1:6.
13.3
All external brick walls shall be constructed in 1:5 cement mortars.
13.4
All partition walls shall be 115 mm thick and constructed in 1:4 cement mortar with two numbers of 8 mm dia bars provided at every fourth course properly anchored with cross walls or pillars.
13.5
All block masonry shall be in accordance with IS 2185 Part I, II & III.
