A macro-element to simulate dynamic Soil-Structure Interaction

This paper presents a macro-element to simulate dynamic Soil-Structure Interaction (SSI). This new numerical tool is suitable for dynamic (seismic) loadings on structures with shallow foundations. It takes into account the plasticity of the soil, the uplift of the foundation, P – θ effects and the radiation damping. The foundation is supposed infinitely rigid while its movement is entirely described by a system of global variables (forces and displacements) defined in its center. The nonlinear behavior of the soil and the uplift of the foundation are reproduced using the classical theory of plasticity. Uplift and plasticity are combined using the theory of multi-mechanisms. Failure is described by an interaction diagram of the ultimate bearing capacity of the foundation under combined loads. The performance of the macro-element is validated using the experimental results of the structure Camus IV. Furthermore, a parametric study on the behavior of a seven-story building shows the capability of the macro-element to consider different types of soils. Based on the results obtained it seems now possible to use this approach to investigate numerically the behavior of a wider variety of configurations.