In the past few decades, dynamic soil–structure interaction (SSI) has been the subject of numerous research studies, with a variety of approaches being developed that are capable of tackling the SSI problem from different points of view. Furthermore, the modeling of structures which exhibit linear or nonlinear behavior has been well developed with numerical methods. Despite the volume of publications and research, dynamic SSI still remains one of the most challenging subjects.
In this study, the application of the time-history response of inelastic structure supported by soil-foundation systems is discussed, using some simple tools and considering a maximum number of parameters to best represent the nonlinear behavior of the soil-structure system. So, 1) based on the substructure method, an approximate 3D impedance function was evaluated through a computational model based on the 2D boundary element method (BEM) and a thin layer method (TLM) Green's function. Horizontal dashpots were incorporated into the soil in plane strain so as to represent the wave propagation toward the perpendicular direction from a slice of the soil. 2) In general, soil-foundation systems show various frequency-dependent impedance characteristics. For the sake of simplification, the lumped-parameter (L-P) model with frequency-independence was used to express the impedance functions in the time domain. The L-P model is usually composed of additional, springs, dashpots and masses. 3) The building (superstructure and L-P model) was modelled by using commercial finite element method (FEM) software. The inelastic time-history response was obtained for the fixed base model and the soil structure system model for the sake of comparison.
Keywords: Boundary Element Method, Thin Layer Method, Lateral dashpots, frequency-dependent impedance, inelastic behavior of the soil-structure system