Vertical vibrations of circular flexible foundations on layered media

The paper presents the analysis of vertical oscillations of a flexible circular plate on the surface of an elastic half-space and an elastic layered system by the 'ring method'. The matrix of influence coefficients for the layered system is evaluated based on the stiffness matrix approach, and numerical integration is used to perform the inverse Hankel transforms. The plate discretization is achieved by the finite difference energy method. Vertical oscillations have been analyzed to determine the displacement and soil reaction distributions at the soil-plate interface, and the impedance functions. The results indicate that the response of a flexible plate strongly depends on the material and geometrical properties of both a soil system and a plate, and the load distribution on the plate. In most cases the behavior of a flexible plate differs significantly from the behavior of a rigid one.