A u-p Formulation for Fully Coupled Dynamic Analysis of Flow and Deformation in Unsaturated Soils

Abstract

A u-p formulation based on the mixture theory is presented for describing the dynamic flow and deformation behaviour of unsaturated soils. In the formulation proposed, the solid displacement, pore water pressure, and pore gas pressure are considered as primary variables. The spatial discretization of the governing equations is achieved using finite element method, whereas the time integration is conducted using the Newmark technique. The coupling between solid and fluid phases is enforced according to the effective stress principle taking suction dependency of the effective stress parameter into account. Numerical examples and comparisons with known analytical solutions are presented, demonstrating the performance of the proposed approach.