P. Mirhashemian - Tarbiat Modares Unaiversity
N. Khaji - Tarbiat Modares Unaiversity
H. Shakib - Tarbiat Modares University

This study proposes a new formulation for modeling soil-structure interaction (SSI) problems. In this direct time-domain method, the half-space soil medium is modeled by spectral element method (SEM) which is based upon a conforming mesh of two-dimensional quadrilaterals, and the structural frame components are modeled by finite element method (FEM). Formulation and various computational aspects of the proposed hybrid approach are thoroughly discussed. To the authors' knowledge, this is the first study of a hybrid SE/FE method for SSI analyses. The accuracy and efficiency of the method is discussed by developing a two-dimensional SSI analysis program and comparing results obtained from the proposed hybrid SE/FE method with those reported in the literature. For this purpose, a number of soil-structure interaction and wave propagation problems, subjected to various externally applied transient loadings or seismic wave excitations, are presented using the proposed approach. Each problem is successfully modeled using a small number of degrees of freedom in comparison with other numerical methods. The present results agree very well with the analytical solutions as well the results from other numerical methods.

Soil-Structure Interaction, Hybrid Approach, Spectral Element Method, finite element method, Elastodynamics