COUPLED FINITE-INFINITE ELEMENTS MODELING OF

The soil-structure interaction analysis of structures is a complex and broad area of research in structural and geo-technical engineering. It deals with study of mechanics of interaction between foundation, soil and superstructure or its parts buried in soil to investigate the interaction behaviour. In common structural design practice the foundation loads from structure analysis are obtained without considering allowance for soil settlements. The foundation settlements are estimated assuming a perfectly flexible structure. A powerful numerical tool like finite element method can be used to analyze the composite system. The finite element modeling of the domain of the building frame-soil interaction system needs variety of isoparametric elements with different degrees of freedom. The superstructure is discretized with conventional isoparametric elements while the soil mass with coupled finite-infinite elements having different decay patterns to model the far field behaviour. This paper presents the modeling of plane frame-foundation beam-soil system for elasto-plastic interaction analysis considering the entire system to act as a single integral compatible structural unit using finite-infinite elements. The forces in the frame members (beams and columns) and the foundation beam have been evaluated and compared with conventional frame analysis