ELASTIC AND ELASTO-PLASTIC WAVE PROPAGATION IN SATURATED AND MIXED-PHASE GROUND

Abstract

The solid and fluid phases in the soil-water mixtures interact with each other through complex internal couplings. To handle the fluid-solid interaction associated with a high frequency, a finite element method using overlapping meshes (known as the ADPC method) has been developed based on Biot¿s u-U formulation. In this method, the prevailing viscous and constitutive couplings are accounted for by means of dashpot-style connector elements and user-defined subroutines. The method is validated using four published 1-D linear-elastic analytical examples and further extended to 2-D and 3-D problems involving non-uniform elements and material nonlinearity. Following the first study of an idealized mixed-phase problem, two fully-coupled 3-D elasto-plastic studies were presented: one with an impulsive loading on the surface akin to that of dynamic compaction in mixed-phase ground and the other simulating a buried explosion in a fully saturated ground. Reasonable results have been obtained by comparing the empirical and centrifuge results.