Material point method for dynamic analysis of saturated porous media (III): two-phase material point method

Under the framework of the original material point method (MPM), a two-phase MPM (tMPM) is proposed to predict the dynamic response of saturated porous media. Because the saturated porous media are composed of solid skeleton and pore fluid, two sets of material points are invoked in the tMPM, which represent the deformation of solid skeleton and pore fluid flow respectively. Based on the u-U form governing equations for saturated porous media, the discrete form of the tMPM is derived explicitly. Adopting the same time integration scheme as that used in the original MPM, the tMPM simulates the coupling behavior of saturated porous media successfully. Compared with the reference solution of the conventional FEM, the validity of the tMPM is demonstrated by the good agreement shown in numerical examples.