Dynamic Stiffness of Foundations on Saturated Poroelastic Soils

Abstract

A boundary element model is presented for the computation of dynamic stiffnesses of strip foundations resting on or embedded in soils that are fluid-filled poroelastic and may also have single-phase viscoelastic zones. The two-phase behavior of the porous medium is represented according to Biot's theory. The interaction between the porous medium and the foundation or the zones of the soil that are viscoelastic is rigorously represented. The contact conditions between the soil and foundation can be pervious or impervious, welded or smooth. The technique is applied to the computation of dynamic stiffnesses of foundations on a saturated poroelastic half-space and on a saturated poroelastic stratum based on rigid or compliant bedrock. Stiffness components are computed and compared with existing results for a half-space and for a stratum. The effects of the properties of the porous medium, the kind of contact between soil and foundation, the depth of the porous stratum, and the compliance of the bedrock on the dynamic stiffnesses are examined. The technique presented in this paper is able to represent more general properties and geometries of the soil than do the existing approaches.