Vertical vibrations of a rigid disk embedded in a poroelastic medium

This paper considers the steady-state vertical vibrations of a rigid circul ar disk embedded at a finite depth below the free surface of a poroelastic medium. Biot's elastodynamic theory for porous media is used in the analysi s. General solutions for axisymmetric poroelastic fields are obtained by us ing Hankel integral transforms. Analytical solutions for influence function s corresponding to four types of buried axisymmetric excitations are derive d. The embedded disk problem is formulated in terms of a set of coupled int egral equations for unknown traction and pore pressure jumps across the dis k. The kernel functions of the integral equations are the influence functio ns corresponding to buried vertical, radial and pore pressure ring loads. T he system of integral equations is solved numerically by discretizing the d isk into several concentric annular rings. Selected numerical solutions for displacements, vertical stress and pore pressure due to a buried fully fle xible disk (uniform pressure) are also presented. The vertical compliances of a rigid disk are examined for different depths of embedment, poroelastic materials and hydraulic boundary conditions. Solutions for traction and po re pressure jumps are also examined. The present results are useful in the study of dynamic response of embedded foundations and anchors in poroelasti c soils. Copyright (C) 1999 John Wiley & Sons, Ltd.