Two and three-dimensional numerical analysis of the progressive failure that occurred in an excavation-induced landslide

A finite element approach, in which an elasto-viscoplastic strain-softening model is incorporated, is used to analyse a landslide that occurred after deep excavations had been carried out for the construction of several buildings at the toe of the slope. The soils involved in the landslide were characterized by a pronounced strain-softening behaviour with the shear strength that abruptly reduces as plastic strain increases. As is well-known, a progressive failure may be triggered in these soils by excavation and it can cause the collapse of the slope after some time. The numerical approach used in the present study allows this phenomenon to be properly simulated. Results from both two-dimensional (2D) and three-dimensional (3D) analyses of the landslide are performed. The results from these analyses confirm the occurrence of a progressive failure within the slope. However, the 2D analysis does not completely account for the failure process that occurred, because of the 3D nature of this process that propagated in both upward and lateral directions. A more realistic simulation of the slope failure is achieved by performing a 3D analysis.