Back-Analysis of the Post-failure Stage of a Landslide in Sensitive Clays

The landslides involving sensitive clays are generally characterized by very high velocity and long run-out distance. These landslides have captured the interest of the geotechnical community since the pioneering works by Skempton and Northey [1] and Bjerrum and Landva [2] inspired by the impressive events occurred in Norway. However, the unavailability of suitable methods of analysis has been one of the main obstacles to the advancement of knowledge about the kinematics of these natural disasters. In the present study, the Material Point Method (MPM) is used to simulate the run-out process 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 analyze the kinematics of landslides in sensitive clays, requiring also a limited number of conventional geotechnical parameters as input data.