TWO-DIMENSIONAL LARGE DEFORMATION FINITE ELEMENT MODELLING OF SENSITIVE CLAY LANDSLIDES

Many large-scale landslides have been observed in sensitive clays. Based on post-slide investigations, the failure patterns can be primarily classified into flowslide, spread, compound, and could be undefined in some cases. The failure pattern depends primarily on soil properties, geometry, topography and loading conditions. In Norway, most of the retrogressive landslides are flowslide. However, in eastern Canada, many spread type failure occurred. The failure mechanisms of the complete process of a large landslide cannot be properly explained using traditional limit equilibrium methods or Lagranginan-based finite element analyses because the former cannot model progressive failure and the latter cannot handle the large deformation due to mesh distortion. In this presentation, the modelling of sensitive clay landslides using a Eulerian-based finite element technique will be presented. The potential factors that change the failure pattern from flowslide to spread, and retrogression and runout distances will be discussed. The simulated failure mechanism might help development of better land-use guidelines in sensitive clay slope areas.