Effect of soil-structure interaction on the peak acceleration of multi-story buildings under wind loads

Abstract

This paper investigates the influence of soil-structure interaction (SSI) on the peak acceleration of multi-story buildings under wind loading, through consideration of the interaction among the soil foundation, pile-raft foundation system, and the superstructure. Numerical analysis results indicate that soil stiffness, expressed through the shear wave velocity Vs, is the most influential parameter on the peak acceleration of the structure; the acceleration decreases significantly as Vs increases and asymptotically approaches the value corresponding to the fixed-base condition. The SSI effect is most pronounced in soft soil conditions, where neglecting this interaction may lead to inaccurate estimates of the dynamic response of multi-story structures. The pile spacing in the pile-raft foundation system has a significant influence on the peak acceleration under soft soil conditions, while the pile slenderness ratio has a minor effect on the peak acceleration under both soft and stiff soil conditions. The raft thickness plays a negligible role in the peak acceleration within the investigated range. The findings of this study may serve as a reference for estimating peak acceleration and for the practical design of multi-story buildings subjected to wind loading under various soil conditions.