Dynamic responses of a tapered tall building to wind loads

Many investigations for mitigating wind-induced excitations of tall buildings have been carried out. The aerodynamic modification of a building shape changing the cross-section with height through tapering, which alters the flow pattern around the building, could reduce wind-induced excitations of tall buildings. The fact that a tapered tall building might spread the vortex-shedding over a broad range of frequencies makes more effective for reducing acrosswind responses has been established. In this paper, to investigate the tapering effect for reducing wind-induced responses of a tapered tall building, high-frequency force-balance test was conducted. Four types of building models which have different taper ratio of 5%, 10%, 15% and one basic building model of a square cross-section were tested under the two typical boundary layers representing suburban and urban flow environment. The effect of wind direction was also considered.