Time domain boundary element formulation for partially saturated poroelasticity

Based on the Mixture theory and the principles of continuum mechanics, a dynamic three-phase model for partially saturated poroelasticity is established as well as the corresponding governing equations in Laplace domain. The three-dimensional fundamental solutions are deduced following Hِrmanderʹs method. Based on the weighted residual method, the boundary integral equations are established. The boundary element formulation in time domain for partially saturated media is obtained after regularization by partial integration, spatial discretization, and the time discretization with the Convolution Quadrature Method. The proposed formulation is validated with the semi-analytical one-dimensional solution of a column. Studies with respect to the spatial and temporal discretization show its sensitivity on a fine enough mesh. A half-space example allows to study the wave fronts. Finally, the proposed formulation is used to compute the vibration isolation of an open trench.