Design Calculations for Structure

DESIGN CALCULATIONS FOR THE RECTANGULAR SHADE STRUCTURE I.

General 1. Design Philosophy The purpose of this calculation is to design the shade structure for its integrity, strength and stability verification. The result of this conclusion is that the structure considered adequate in meeting the required of design criteria. 2. Unit of Measurement Unit of measurement in design shall be in Metric system.

II.

Design Calculations 1. Design Code and reference: BS 5950: Structural use of Steel. Code of practice for steel design BS 8110: Structural use of Concrete. Code of practice for concrete design Wind loads as per CP3 STAAD – Structural Program for calculations. 2. Materials Steel Columns - Pipes of OD 168mm with 4mm thick Horizontal, Curved and Connecting members, Steel Pipes of OD 60mm with 3.2mm thick Small Vertical Pipe of OD 48mm with 3.2mm thick The modulus of elasticity of steel – E = 210000 N/mm2 Ultimate Bending stress steel – Po - σ = 275 MPa = 275 N/mm2 Ultimate Tensile Stress steel – Pa = 435 MPa = 435 N/mm2 Ultimate Shear Stress steel – Pv = 0.6X Po = 0.6X275 = 165 MPa = 165 N/mm2 All bolts used shall be grade 8.8 or high yield. 3. Loading Dead Load – Self weight is considered Dead Load – Fabric Load (350 gm/Sqm) Wind loads (WL) calculated as per CP3: ch.V The canopy is located at a height of 3.0m. Basic wind speed assumed as 45 m/s. Basic wind speed V = 45.0 m/sec Design wind speed Vs = V x S1 x S2 x S3

Where, Topography factor, S1 = 1.0 For the calculation of S2, ground roughness, building size and height above ground, factor S2 = 0.74, as per CP3: Chapter V: Part 2, Clause 3 (Country with many wind breaks; small towns; outskirts of large cities), class C for 10m average height. Statistical factor, S3 = 1.0 Design wind speed Vs = 45.0 x 1.0 x 0.74 x 1.0 Design wind speed Vs = 33.3 m/sec Wind pressure q = k Vs2 K – constant = 0.613 Wind pressure q = 0.613 x (33.3)2 Wind pressure q = 680 N/m2 or 0.68 KN/m2 Wind Pressure q = 0.68 KN/m2 The maximum and minimum pressure co-efficients are, Cp = +0.7, and -0.7, Net wind uplift Pressure = Cp X q Net wind uplift Pressure = -0.70 X 0.68 = 0.476 KN/m2 Net wind Pressure = Cp X q Net wind Pressure q = 0.70 x 0.68 = 0.476 KN/m2 4. Load Combinations Design & Ultimate factors are considered. as per BS standard, UL = 1.40 DL + 1.4 WL UL = 1.0 DL + 0.8 WL 5. Design Method

The shade structure with a span of 8.0m and width is considered and as shown and the average centre to centre spacing between the pipes is considered as 8.0m. Loads are calculated on the spacing between the structures which are as follows: Dead Loads: a) Self Weight to be checked from the program Dead Load = 0.035 X 8.0 = 0.28 KN/m Wind Loads: a) Uplift wind load = 0.476 X 8.0 = 3.81 KN/m b) Downward wind load = 0.476 X 8.0 = 3.81KN/m To check the maximum length of the canopy structure against all the above loading combination and to be on factor of safety (see attached calculations made by the structural program STAADPRO). 6. Conclusion: All the materials used in the shade structure for all spans are structurally sufficient and meets its intended purpose.