Structural
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STRUCTURAL
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STRUCTURAL
INTRODUCTION
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Structural
The proposed cricket stadium is located in Providence, Guyana
and shall be constructed as per the ICC norms for the World Cup to be
held in 2007. The stadium of 15,000 capacity is to be constructed
under the Ministry of Public Works and Communications with a grant
from the Govt of India. This design basis report is drawn only for the
structural design of the works in the stadium complex project.
As listed in the Architectural basis, there are various buildings in
the complex, which serves the requirement for the intended capacity.
The report tends to highlight the general design philosophy adopted in
the structural design of the elements and also gives an overview of the
basis of structural analysis and design adopted to arrive at the estimate.
The report also highlights the various methods and loads assessed for
the purpose of structural design of elements. It also brings out the
reason for adopting various principles chosen for design and gives a
comprehensive list of the codal provisions chosen. At the end the list of
codes adopted for design is furnished. All materials shall be as per the
Indian standards and design shall comply with BS standards as listed
below. The Indian Standards are also listed for clarity.
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DESIGN PHILOSOPHY
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Structural
The main buildings in the stadium complex are the stands, members and player's pavilion block, venue operating
centre, media centre and landscaped seating stand apart from service buildings and underground structures.
The structural system adopted for the buildings are concrete/structural steel framed conventional beam slab and
column structures on pile caps over bored cast-in-situ concrete piles/pre-cast concrete piles/green heart timber piles. The
slabs are proposed in composite construction with concrete on profiled metal decking (serving as reinforcement). The
stands are designed with pre-cast bleachers on raker beams in concrete/structural steel. The roof covering the stands are
designed with structural steel elements in profiled sections to match the architectural form. The columns in cast-in-situ
concrete/structural steel have insert plates/base plates to seat the roof-supporting member. The structures are analysed
for dead load, live load and wind loads as per the codal provisions. Waterproofing on concrete surfaces exposed to
atmosphere is done with reinforced modified bituminous membrane and is protected by cement concrete tiles. The
waterproofing of sunken slabs in toilets is also achieved with the same material. All structural steel surfaces are protected
from corrosion with anti-corrosive paint.
DESIGN LOADS
Dead Loads
The self weight of the various elements are computed based on the unit weight of materials as given below:
Unit Weight kN/m 3
Material
Steel
78.5
Plain Cement Concrete
24
Reinforced Cement Concrete
25
Cement Concrete Screed
24
Soil
20
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Imposed Loads
As per BS:6399 (Part 1)-1996 the building is classified as Public Assembly building.
Structural
The superimposed loads or otherwise live load is assessed based on the occupancy classification as per BS:6399(Part 1)1996 for assembly building. The imposed loads (in kN/m2) considered are as listed below:
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Occupancy Classification Load (kN/m 2 )
a) Assembly areas:
1) with fixed seats
4.0
2) without fixed seats
5.0
b) Kitchens, laundries
3.0
c) Stages
7.5
d) Corridors, hallways, stairs
4.0
e) Dressing rooms
2.0
f) Areas for equipment
2.0
g) Toilets and bathrooms
2.0
On flat roofs, sloping roofs and curved roofs with slopes up to and including 10 degrees, the imposed loads due to
use or occupancy of the buildings and the geometry of the roofs are given below:
As per cl 6.2, BS:6399 (Part 1)-1996
a) For roofs with access provision
1.5
b) For roofs without access provision
0.75
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On sloping roof of slope greater than 10o, as per clause 6.3 of BS:6399(Part1)-1996 the imposed loads (kN/m2 of the plan
area) that are likely to act permanently are as follows:
1.5
(On roof / terrace)
Partitions
1.0
(wherever applicable)
False ceiling
0.5
wherever applicable)
Structural
Waterproofing*
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Structural slab shall be sloped suitably to avoid achieving requisite slopes with screed/brick bat coba
Bleachers are designed to resist a horizontal force applied to seats of 3.0 kN per linear meter along the line of seats and
1.5 kN per linear meter perpendicular to the line of seats.
Wind Load
The wind pressure is calculated based on the data furnished below and as per the provisions laid in BS:6399 (Part 2)-1997
Basic Wind speed
= 50m/sec
Maximum gust
= 30mph (13.5m/sec) As given
Mean probable
= 50 years
(As assessed from UBC)
DESIGN LIFE OF STRUCTURE
Building Type factor Kb
= 1.0
Ground roughness category
= town
Built up areas with an average level of roof tops at least Ho
=5m above GL
Dynamic Augmentation Factor Cr
=0.03
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Directional Factor Sd
= 1.0
Altitude Factor Sa
= 1.0
Seasonal Factor Ss
= 1.0
Probability Factor Sp
= 1.0
Site Wind Speed Vs
= Vb x Sa x Sd x Ss x Sp
= 50 x 1 x 1 x 1 x 1 x 1
Structural
Static Simplified method is used for design for wind loads with the following parameters as per cl 2.2 BS:6399 (Part2)-1997
= 50m/sec
Effective Wind Speed = Vs x Sb
Where Sb is the terrain and building factor obtained from cl 2.2.3.3 of BS:6399(Part2)-1997
Earthquake Load
Guyana is not within the earthquake belts and also does not figure in the places listed in the seismological active zones. It
has been mentioned that Guyana experiences tremors every 5-10 years. Earthquake loads are not considered for analysis
and design. With the given conditions it is assumed that the wind load on the structure would be sufficient for the lateral
loads that would be generated during the tremors.
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Load Combinations
Structural
Primary loads are combined in accordance with relevant stipulations in BS:8110(Part 1)-1997. The combination that
produces the most unfavourable effect in the building, foundation or structural member concerned is adopted for design.
Load Type
Load
Comb.
Dead
Adverse
Imposed
Beneficial
Adverse
**
Wind
Beneficial
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c
1
1.4
1.0
1.6
0.0
2
1.4
1.0
-
-
3
1.2
1.2
1.2
1.2
1.2
1.0d
c
1.2
1.0d
c
1.2
1.0d
—
1.4
1.2
**Eartha and Waterb Pressure
1Dead and Imposed (and earth and water pressure)
2Dead and Wind (and earth and water pressure)
3Dead and Imposed and wind (and earth and water pressure
aThe
earth pressure is that obtained from BS:8002 including an appropriate mobilisation factor. The more onerous of the
two factored conditions should be taken.
bThe
value of 1.2 may be used where the maximum credible level of the water can be clearly defined. If this is not
feasible, a factor of 1.4 should be used.
cUnplanned
excavation in accordance with BS:8002, 3.2.2.2 not included in the calculation.
dUnplanned
excavation in accordance with BS:8002, 3.2.2.2 included in the calculation.
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ANALYSIS METHOD
Structural
The analysis of the structure is carried out using the STAAAD Pro-2003. Appropriate loads and its
combinations, as per relevant clauses in BS codes as described in this report are chosen for analysis and design.
Precast elements are analysed manually for handling, transportation and service stresses.
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DESIGN LIFE
The design life of the structure is considered as 50 years. This requirement is not applicable for replaceable
materials.
DESIGN METHODOLOGY
All structural elements shall be designed according to the Limit State Method as specified in BS:8110 for
reinforced concrete elements and BS:5950 for structural steel elements.
FOUNDATION
As per recommendations of the soil investigation report, only piles are considered as foundations. The
various types of piles considered for supporting load-bearing columns/structures are bored cast-in-situ concrete
piles, pre-cast concrete piles and green heart timber piles. The vertical capacity of the pre-cast concrete piles of
20m length is 34mT and that of 23m green heart timber piles is 18mT.
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Concrete item
Grade
Max size of
Type of
aggregate (mm )
cement
Pile Concrete
C35
20
OPC
Pile Caps
C40
20
OPC
Column
C40
20
OPC
Slabs and beams
C35
20
OPC
Retaining walls
C35
20
OPC
Precast Elements
C50
20
OPC
Structural
CONCRETE
The grade of concrete and type of cement adopted for the various structural
REINFORCEMENT
For all structural RC elements steel reinforcement used shall be of Fe 415 grade conforming to IS:1786-1985 or equivalent.
NOMINAL COVER TO REINFORCEMENT
The cover to concrete shall be as per the guidelines laid in cl 3.3 of BS:8110 Part 1-1997. The cover shall also
satisfy the requirements of 2h fire rating.
DESIGN STANDARDS
The relevant Standard codes, as given below, have been followed for structural design
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Codes
Description
BS:648-1964
Schedule of weights of building materials
BS:4449-1997
Specification for Carbon Steel Bars for
Structural
British Standards
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Reinforcement of Concrete
BS:4461-1978
Specification for Cold Worked Steel Bars for the
Reinforcement of Concrete
BS:6339 Part-1-1996 Code of practice for Dead and Imposed Loads
BS:6339 Part-2-1997 Code of practice for wind loads
BS:6339 Part-3-1988 Code of practice for Imposed Roof Loads
BS:8002-1994
Code of Practice for Earth Retaining Structures
BS:8004-1986
Code of practice for Foundations
BS:8110 Part-1-1997 Structural Use of Concrete-Code of practice for
design and construction
BS:8110 Part-2-1985 Structural Use of Concrete-Code of practice for
special circumstances.
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Codes
Description
BS:8110 Part-3-1985
Structural
British Standards
Structural Use of Concrete-Design charts for singly
reinforced beams, doubly reinforced beams and
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Rectangular columns.
BS:8102-1990
Code of Practice for Protection of Structures
against Water from the Ground
BS:5950 Part 1-2000
Structural Use of Steelwork in Building-Code of
Practice for Design in Simple and Continuous
Construction: Hot Rolled Sections
BS:5950 Part 2-1994
Structural Use of Steelwork in BuildingSpecification for Materials, Fabrication and
Erection: Hot Rolled Sections.
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Codes
Description
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IS: 456-2000
Code of Practice for Plain and Reinforced Concrete
IS: 800-1984
Code of Practice for General Construction in Steel
IS: 808-1989
Dimensions for hot rolled steel beams, columns,
Structural
Indian Standards
channels and angle sections
IS:875-1987(Part-1) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
Dead Loads — Unit Weights of Building Materials
and Stored Materials
IS:875-1987(Part-2) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
Imposed Loads
IS:875-1987(Part-3) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
Wind Loads
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Codes
Description
Structural
Indian Standards
IS:875-1987(Part-5) Code of Practice for Design Loads (Other than
Earthquakes) for Buildings and Structures.
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Special Loads and Load Combinations
IS:1786-1985
Specification for High Strength Deformed Steel
Bars and Wires for Concrete Reinforcement.
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