Development of Analytical Techniques in Soil-Structure Interaction

Abstract

The development of soil-structure interaction during the last quarter of a century has followed two distinctive paths yielding the Direct and Substructure Methods of analysis. In current state-of-the-art both methods are represented by quite similar models with differences being restricted to the dynamic boundary conditions defined along the boundary of the finite soil region considered. Therefore achieving a common formulation equally applicable to both methods is possible. Within the framework of Substructure Method, the Boundary Element Method has been very effective in handling geometrically irregular conditions at the soil-structure interface. For the stiffness problem of embedded foundations, the determination of Green functions in unexcavated, virgin soil condition and the subsequent subtraction of the excavation zone are the two main steps of the analysis concept called Analytical Excavation. Effective input motions of flexible and rigid foundations are easily obtained once the dynamic stiffness and free-field response of virgin soil are known. Examples presented are the stiffness and damping influence coefficients as well as the components of effective base input motion of a rectangular foundation embedded into a damped half plane.