Simplified analysis of layered soil-structure interaction

The interaction of an arbitrary structure with its foundation soil is treated by representing the stratified soil with the end of a linear elastic half space model with specific geometrical and elastic properties for its layers. The proposed procedure is based on a purely analytical treatment of the underlying soil model, as well as on the use of a structural model with fictitious supports inserted at the contact nodes of the foundation elements with the soil surface. The availability of a general purpose finite element program is a prerequisite in order to carry out the analysis of the structural model. The analysis for an arbitrary static loading is performed by using the stiffness matrices of the soil surface and of the structure with respect to their contact nodes. This approach provides a flexible framework to perform parametric studies to include the variability of soil properties. Three numerical examples are presented and the results are compared with those based on Winkler's assumption of modulus of subgrade reaction.