Dynamic Analysis of Tall Buildings Considering Different Plan Aspect Ratio

The number of high-rise buildings has increased significantly over the last 50 years. Companies have traditionally used high-rise buildings as office space, but residential use is growing in popularity. Due to the increased demand for new construction, there is a limited supply of land that can be used for construction. As a result, it is necessary to construct a structure using the resources at our disposal. This study focuses on the behavior of tall buildings under different aspects of wind loading. As per guidelines of Indian standards, the tall buildings plan aspect ratio should not be greater than 5. This study investigates the effect of different plan aspect ratios of tall buildings exposed to wind and seismic loading. Previous research has shown that the longer side of the building will be more affected by wind loading. Therefore, using CFD Analysis, dynamic wind analysis is performed for tall buildings and Different parameters are compared to study wind behavior in both along and across directions of the building. A gust factor is evolved to determine the along-wind and across-wind forces on the building. The result obtained was used in software to analyze and design the building. Five different plan aspect ratios (1:4, 1:5, 1:6, 1:7, 1:8) were considered for the study. The results from CFD analysis show that as the plan aspect ratio increases from 1:4 to 1:8, the parameters like Suction velocity (15.74%), Eddy Viscosity (12.6%), Turbulence Kinetic Energy (12.87%), Negative pressure on the leeward side (7.49%), Maximum positive pressure on the building face (12.32%) and Reattachment Length of wind flow (29.22%) have also increased by the corresponding percentage. The pressure coefficient also varies depending on the behavior of the wind and flow separation at different points along the building height.