MATERIAL POINT METHOD FOR HYDRO-MECHANICAL PROBLEMS AND ITS APPLICATION TO SEEPAGE FAILURE ANALYSES

In this study, a fluid-soil coupled MPM algorithm based on Biot's theory is proposed for solving hydro-mechanical problems of soil including large deformation problems. The proposed algorithm can be computationally efficient for dealing with the large deformation problems since it uses an Eulerian background mesh for solving the equation of motion of soil in a similar manner as the conventional FEM using physical quantities such as effective stresses and pore water pressures introduced from Lagrangian particles which consist of solid and liquid phases. In order to examine the numerical stability and accuracy of the method, simulations of one-dimensional consolidation test were carried out and the results were compared to the analytical solution. The effect of mesh size and particle number per mesh on the accuracy of the proposed algorithm was also discussed. In order to show the capability of the proposed method, an experiment on a large scale levee failure due to seepage was simulated. The computed large displacements and the behavior of the failed levee matched well with those from the experiment. The effect of change of pore water pressures due to seepage to the effective stress paths in the levee was also discussed.