A MULTIPHASE COUPLED 2-POINT MPM FOR SIMULATING LARGE DEFORMATION OF UNSATURATED SOIL

Abstract

The Material Point Method (MPM) is a kind of particle method, which is advantageous for large deformation analysis because it avoids mesh tangling as grid methods normally encounter. In multiphase geotechnical analysis, it is necessary to consider the advection between phases when the relative motion between solid and liquid phases is large, such as during large deformation of highly permeable ground. In this study, a new formulation and discretization of the solid-liquid-gas three-phase 2-Point MPM is proposed. In this study, we propose a new formulation and discretization of the solid-liquid-gas three-phase 2-Point MPM, which can take into account the advection between the solid and liquid phases. The formulation of the proposed method is a u-U formulation, and thus it is not necessary to use advection term between the solid and liquid phases by using Lagrangian particles for the two phases. Small and finite deformations of the one-phase and two-phase systems are verified through numerical analysis. Finally, dynamic liquefaction analysis of embankment in solid-liquid-gas three phases was conducted to confirm the applicability of the method to large deformation phenomena with significant relative motion between solid and liquid phases.