Post-failure stage simulation of a landslide using the material point method

Traditional numerical methods such as the finite element method are usually used to analyse the slope response in the pre-failure and failure stages under the assumption of small deformations. However, these methods are generally unsuitable for simulating the post-failure stage of landslides due to the occurrence of large deformations. The material point method (MPM) is a numerical technique capable to overcome this limitation. In the present study, MPM is used to carry out a two-dimensional analysis of the run-out process of the Senise landslide that occurred in Southern Italy, in 1986. Accuracy of the method is assessed by comparing the final geometry of the landslide observed just after the event and the magnitude of the measured displacements, to those provided by the numerical simulation. The calculation results match fairly well the observed ones when two slip surfaces detected by the inclinometers, are accounted for in the analysis. An additional improvement of simulation is achieved taking into account the presence of some buildings and retaining walls existing in that area. Kinematics of the landslide is also investigated. The results show that the Senise landslide was a translational slide moving along two planar slip surfaces located in thin layers of clayey silt. In addition, these results demonstrate that a suitable analysis of the post-failure stage can lead to a better understanding of the complex mechanical processes that characterise some landslides, and thereby help in establishing the most effective stabilization measures.