Predicting crosswind response of tall buildings: Base isolation and nonlinear aeroelastic effects

Abstract

This study introduces an analysis framework to evaluate the crosswind response of tall buildings under the influence of base isolation and nonlinear aeroelastic effect near the vortex lock-in wind speed. The motion-induced and buffeting forces are determined based on those in a building with a fixed base. The primary focus is on modeling the motion-induced force in tall buildings with base isolation, where no pre-existing model exists. The fundamental modal displacement is used to describe the building motion relative to the base. The Bouc-Wen model is employed to capture the hysteresis in the relation of shear force and displacement of the isolation system. Through response history analysis, the response statistics of a 65-story building with a square cross-section are determined and compared with those of a fixed-base building. An investigation is conducted to examine the impact of different isolation layer parameters on building response. Additionally, this study explores how the motion-induced force model influences the building response. The findings indicate that base isolation effectively mitigates nonlinear aeroelastic effects, leading to a significant reduction in crosswind response.