Influence of Ground-Motion Characteristic Period on Reductions in Peak Dynamic Shears Owing to Base-Slab Averaging

Abstract

The relatively high story shears observed in inelastic dynamic analysis of shear wall buildings are attributed to higher mode effects. At the same time, soil-structure interaction can alter the frequency content of incident ground motions. This study examines the effect of base-slab averaging on peak story shears for an eight-story reinforced concrete shear wall building. Base slab averaging was found to reduce peak story shears. The reduction in peak story shears was found to be a function of the characteristic period of the ground motion; the largest percentage reductions are found for ground motions having the smallest characteristic periods.