Application of the material point method in the modeling of arching effects behind retaining walls with active movements

Numerical modeling of problems with large deformations is one of the main challenges in computational mechanics. Conventional numerical approaches cannot accurately model large deformations. Recently, the material point method (MPM), which comprises advantages of Eulerian and Lagrangian descriptions of movement, has been developed to solve complicated numerical problems such as large deformations. In this paper, the MPM method is employed to model the behavior of a soil mass behind a rigid retaining wall during active movement. It is the first time that the accuracy of the MPM method has been evaluated in the modeling of retaining walls with active movements. The accuracy and efficiency of the MPM are measured using two small-scale physical modeling tests and an analytical approach (for translational motion). In addition, a comparison between the results of the MPM and conventional FEM is provided. It is shown that the MPM can model the arching effect in the soil media better than the FEM; however, the material point method leads to smaller stresses on the wall compared to experimental results. It is demonstrated that the employed MPM can accurately model arching effects on the soil media behind the retaining walls with active movement. For transitional movement, arching effects lead to the upward movement of the resultant horizontal force on the wall, which occurs higher than 1/3H (H is the height of the wall). The achieved results indicate that the traditional methods can lead to overestimated designs without considering arching effects.