Non-Linear Seismic Soil-Structure Interaction Analysis of Structures Based on the Substructure Method

In this paper, a numerical model for wave induced vibrations in buildings is developed based on a substructure method by using original Matlab software developed by the authors. A dynamic analysis of the structure subjected to an incident wave field, is performed using the subdomain formulation. The structure is analysed with a finite element method and the unbounded soil domain is computed with a boundary element method using the Green''s functions of a layered halfspace.The problem of eigenfrequencies for embedded foundations in the frequency range ofinterest for seismic wave induced vibrations is addressed. A weakly singular boundaryintegral equation in elastodynamics for heterogeneous domains is presented, whichcombines the boundary integral equations in terms of the displacement and its normalderivatives. Based on an extensive parametric study, general conclusions are drawn forpractical range of dimensionless parameters. Insight in the effect of soil-structure interaction and the determining factors for seismic wave induced vibrations is obtained from the results of parametric study. The influence of the type of foundation (rigid or flexible, surface or embedded, slab strip or box foundation) is specially emphasized.