Structural. STRUCTURAL. STRUCTURAL. INTRODUCTION
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.
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.
The self weight of the various elements are computed based on the unit weight of materials as given below:
As per BS:6399 (Part 1)-1996 the building is classified as Public Assembly building.
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:
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
Load Combinations with the following parameters as per cl 2.2 BS:6399 (Part2)-1997
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.
ANALYSIS METHOD with the following parameters as per cl 2.2 BS:6399 (Part2)-1997
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.
The design life of the structure is considered as 50 years. This requirement is not applicable for replaceable materials.
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.
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.
CONCRETE with the following parameters as per cl 2.2 BS:6399 (Part2)-1997The grade of concrete and type of cement adopted for the various structural
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.
The relevant Standard codes, as given below, have been followed for structural design