On the pseudo-coupled winkler spring approach for soil-mat foundation interaction analysis

Abstract

Analysis of the interaction between mat foundations and the supporting soil is often performed with the soil being represented by vertical translational springs. This study sheds light on what must be the distribution of spring stiffness coefficients under a mat in order to get the same mat deflections and bending moment diagrams as in the case of a mat resting on a three-dimensional linear elastic continuum. For this purpose, the spring stiffness coefficients were directly back-calculated at each mat node from the results of finite element analyses that treat the soil as a 3D continuum. Parametric runs are performed to investigate the influence of the soil elastic properties, slab geometrical characteristics and column load configurations on the back-calculated spring stiffness spatial distributions. The computational results of the present study indicate that spring stiffness distributions often assumed currently in practice may lead to a significant underestimation of the mat bending moments.