Modeling Using Coupled FEM-SBFEM for Three-Dimensional Seismic SSI in Time Domain

Abstract

For soil-structure interaction (SSI) problems, accurate modeling of the unbounded domain is an important issue. This paper deals with the three-dimensional seismic SSI analysis based on the substructure method by coupling the FEM and the scaled boundary FEM (SBFEM) approaches. The entire analysis is performed in the time domain making the proposed approach capable of dealing with nonlinearity of soil. To verify the developed program, the results from the present analysis are compared with those available in the literature. This verification has been performed for both externally applied dynamic load and seismic load. The effect of boundary conditions on the SSI response is evaluated. The numerical study performed indicates that the SBFEM can act as a computationally efficient boundary when compared with the conventional viscous dashpots. Next, application of the FEM-SBFEM for SSI problems is demonstrated. A dam-foundation interaction analysis is carried out, and the effect of the inhomogeneity of the foundation soil on the dynamic response of the structure is evaluated. In addition, seismic SSI analysis of a building is carried out for a real earthquake excitation. The effects of the dynamic characteristics of soil and structure on the dynamic SSI response are analyzed.