Effect of strain softening behaviours on run-out distance of a sensitive clay landslide

Abstract

Reliable prediction of landslide triggering threshold and landslide run-out distance is essential for hazard risk assessment. The paper focuses on studying slides in sensitive clays, which represent a major geohazard in many countries including Norway, Sweden and eastern Canada. Large deformation finite element (FE) analyses were performed using the Coupled Eulerian-Lagrangian (CEL) method in Abaqus, which allows for capturing of the full progressive failure mechanism (initiation, propagation and breakoff) involved in a sensitive clay slide. The 1984 slide in Vestfossen, Norway, was chosen as problem case of progressive failure in sensitive clay to be back-calculated by using the CEL FE-model. It is found that the failure mechanism predicted by the FE-analysis agrees reasonably well with the historical failure mode observed at Vestfossen. A parametric study has been performed on the remoulded shear strength as well as the rate of strain softening of the sensitive clay in order to evaluate their effects on the landslide run-out distance.