Seismic soil–structure interaction in buildings on stiff clay with embedded basement stories

Abstract

The increasingly popular performance-based design approach requires that soil–structure interaction (SSI) analysis become an integral part of the seismic evaluation. This is particularly important for structures with substantial embedment. The primary objectives of this study are twofold: (i) evaluate the SSI effects for buildings with a basement and (ii) evaluate the ability of two analytical methods to account for SSI effects in seismic design — an analytical solution for kinematic SSI and a nonlinear finite element model. Scaled model shaking table tests were performed on a model building with an embedded basement founded in a synthetic stiff clay deposit enclosed in a laminar soil container. The model structure used in this study comprised a simple single-degree-of-freedom structure with a modular box foundation designed to permit consideration of structures with different basement embedment depths. The experimental results showed that the ratio of effective period of the soil–structure system to that of the structure ([Formula: see text]) decreased for the long-period structure and increased for the short-period structure, with increasing embedment. The results confirm the ability of the analytical techniques to predict with reasonable accuracy the SSI effects for buildings with embedded parts.