Numerical investigations of retrogressive failure in sensitive clays: revisiting 1994 Sainte-Monique slide, Quebec

Retrogressive slope failure is ubiquitous in regions of abundant sensitive clays with its mechanism yet to be understood comprehensively. This study gives numerical investigations of retrogressive slope failure with a focus on the 1994 Sainte-Monique slide, Quebec, using a large deformation finite element method. Failure mechanisms and post-failure behaviours including the global kinematics and retrogression distance are highlighted with controlling factors discussed in parametric studies. Key features of post-failure behaviours of the 1994 Sainte-Monique slide are reproduced with the configuration of sliding mass deposits comparable to the site investigations. Post-failure kinematics and retrogression distance are sensitive to sensitivity, brittleness and viscosity of soils and riverbed geometry. Parametric studies may contribute to assess potential retrogression recurrence in the region and its retrogression distance upon current set of in situ parameters.