An MPM-FDM coupled simulation method for analyzing partially-saturated soil responses

A Coupled MPM-FDM Analysis Method for Multi-Phase Elasto-Plastic Soils

“…The computational grids for the MPM formulation can be chosen arbitrarily, and the same grids are used in the FDM formulation. The displacement is deˆned at each node of the computational grid and the pore water pressure is allocated at the center of the grid (Higo et al, 2009). With regard to the arbitrary properties of the computational grids, it is fair say to that the FVM is compatible with the coupling with the MPM.…”

“…For analyzing the mechanical behaviors of unsaturated soils, the governing equations for solid, water and air phases considering the interactions among the three phases are formulated by the u-p method based on the theory of porous media (Ehlers et al, 2004). In the formulation, a simpliˆed three-phase method is used in which the compressibility of air is assumed to be very high, whereas the soil particle and the pore water are incompressible as compared with the air (Oka et al, , 2008a; Kato et al, 2009aKato et al, , 2009bHigo et al, 2009); namely, the three-phase method can be simpliˆed into the soil-water coupled two-phase mixture theory. The solid phase is considered as an elasto-plastic body modeled by a cyclic elasto-plastic constitutive equation for sandy soil proposed by Oka et al (1999).…”