Study of soil-structure interaction effect on ground movement using a laminar box

Abstract

In current design practice, the response of a structure subjected to earthquakes is estimated using the free-field ground motion records. During an earthquake the superstructure interacts with the supporting soil and thus alters the excitation characteristics. Hence, depending on the degree of soil-structure interaction (SSI) a consideration of the seismic action of structure using free-field ground motion may not be appropriate. This study focuses on the determination of more realistic excitation experienced by the superstructure during earthquakes. The difference between ground motions under two configurations, i.e. soil with and without the structure, will be discussed. A laminar box that allows shear deformation of soil was utilized in a series of shake table tests. The excitation applied to the laminar box was simulated based on the Japanese design spectrum. The structure considered represents a scaled model of a multi-storey building. Wireless accelerometers were embedded within the sand to measure the response of the soil during shaking for the two considered configurations. The effect of SSI on the ground excitation of the structure will be discussed.