Abstract
This paper deals with the dynamic stiffness (i. e., the complex stiffness) under rigid rectangular foundations resting on an elastic two-layered medium. This is a problem belonging to mixed boundary value problems which are not easily solved by an analytical approach. To overcome the difficulties of analysis the authors employ a numerical method, in which the contact area of the foundation is divided into a finite number of rectangular sub-regions, and a system of linear simultaneous equations with respect to the unknown contact pressures is derived by introducing the influence functions. In this paper the authors mainly investigate the effects of the layering on the dynamic stiffness and the difference in the dynamic stiffness between the relaxed and welded boundary conditions on the contact plane.
