An analytical approach to reduce mesh dependency in the numerical simulation of landslides involving brittle rocks

This paper focuses on the numerical simulation of the deformation processes occurring in the slopes when soft rocks with strain-softening behaviour are involved. In these circumstances, a progressive failure may occur with the consequent motion of the unstable rock mass in the post-failure stage. This problem can be only solved using advanced numerical techniques capable also of accounting for the occurrence of large deformations. However, the solution is generally mesh dependent and may be affected by lack of convergence. In the present study, the material point method (MPM) is employed to simulate the occurrence of large deformations, in conjunction with a strain-softening Mohr-Coulomb constitutive model in which the shear strength parameters are reduced with increasing strains. To reduce the effects of the mesh dependency on the numerical solution, a simple analytical procedure based on the results of direct shear tests is adopted. This methodology is completely analytical and requires few parameters with a clear physical meaning and of simple experimental determination. Some simulations are performed to assess the reliabil-ity of the used procedure.