Modeling the Effects of Soil-Structure Interaction on a Tall Building Bearing on a Mat Foundation

The interaction of a building, its foundation and the underlying soils may have important effects on the behavior of each of these components as well as on the overall system behavior. For example, the relative stiffness of a building structure, its mat foundation and the soils that support the foundation will influence the stresses and displacements of both the structure and soil. Soil-structure interaction (SSI) effects are sometimes neglected by the use of a structural model supported on a fixed base. Other simple models assume an ideally flexible or infinitely rigid foundation on an elastic subsoil. An investigation of the effects of SSI on the stresses and displacements in the structure and the soil of a model fifty-story steel frame structure with a concrete mat foundation bearing on a deformable soil was undertaken as a means of best understanding how to perform and apply SSI analyses. The study included investigating the effects of the stiffnesses of the building, its mat foundation and an elastic subsoil on the stresses, internal forces and displacements of the building, foundation and subsoils. The soil-structure model also considered the effects of foundation embedment.