ANALYSIS OF WIND EFFECT ON FLAT ROOF AND PYRAMIDAL ROOF STRUCTURE USING ETABS

The present study investigated the comparative wind behavior of flat roof and pyramidal roof high-rise reinforced concrete structures using ETABS software according to IS 875 (Part 3): 2015 provisions. A G+20 RCC building having a total height of 70 m was analyzed under wind loading conditions. Based on the analysis results, it was observed that roof geometry significantly influences the aerodynamic behavior and structural response of high-rise buildings. The pyramidal roof structure demonstrated improved performance in terms of displacement, drift, and base shear compared to the conventional flat roof structure. The maximum storey displacement in the flat roof structure was observed as 188.67 mm in the X-direction and 304.07 mm in the Y-direction, whereas the pyramidal roof structure showed reduced displacement values of 179.75 mm and 289.53 mm respectively. This indicates a reduction of approximately 4.70% in the X-direction and 4.78% in the Y-direction. Similarly, the maximum storey drift values also showed slight improvement in the pyramidal roof structure. The maximum storey drift in the X-direction reduced from 0.004500 to 0.004482, while the Y-direction drift reduced from 0.007306 to 0.007275. This indicates improved lateral stability and aerodynamic performance of the pyramidal roof structure under wind loading conditions. The base shear values also reduced in the pyramidal roof structure. The maximum base shear decreased from 8450 kN to 8015 kN in the X-direction and from 9120 kN to 8675 kN in the Y-direction, resulting in approximately 5.14% and 4.87% reduction respectively. Overall, the study concludes that pyramidal roof systems improve aerodynamic efficiency and reduce wind-induced response in high-rise buildings. Therefore, pyramidal roof configurations may be considered more effective and structurally efficient compared to conventional flat roof systems for buildings located in wind-prone regions.

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