Analysis of a landslide in sensitive clays using the material point method

Slope movements are generally classified in four different phases: pre-failure, failure, post-failure and eventual reactivation. In engineering applications, the pre-failure and failure phases are usually analysed using traditional numerical techniques, such as the finite element method and the finite difference method. However, these methods are often based on the assumption of small deformations, and consequently are unsuitable for analysing the slope behaviour during the post-failure stage, since this latter is usually characterised by very large deformations. To overcome this shortcoming, the material point method (MPM) is employed in the present study. Specifically, MPM is used to perform an analysis of a landslide in sensitive clays that occurred at Saint-Jude (Québec, Canada) in 2010. To assess the accuracy of the analysis, the final profile and the displacement magnitude detected after the event are compared to those obtained by the numerical simulation. The results provided by MPM are in satisfactory agreement with field observation. The failure mechanism and the development of the failure surface within the slope are also reproduced successfully. These results also show that MPM is an attractive method to predict the kinematics of landslides in sensitive clays, requiring also a limited number of conventional geotechnical parameters as input data.