CONTINUUM-DISCONTINUUM MODELLING OF FAILURE AND EVOLUTION MECHANISMS OF DEEP SEATED LANDSLIDES

Deep seated landslides from massive rock slope failure are poorly understood and need be further investigated. The objective should be to gain the necessary confidence for predicting the likely behavior, assess the risk associated, and develop robust recommendations based on the instability scenarios which can be anticipated. This is to be done in view of the many complexities involved which encompass the understanding of the underlying mechanisms, the initial and post-failure behavior, and the different secondary processes resulting from instability. This paper shows that by using advanced numerical modeling methods such as the combined finite-discrete element method (FDEM), one is in position to contribute to such an understanding. To illustrate the potential of the FDEM in the simulation of typical instabilities, the Beauregard landslide, located in the Aosta Valley (NW Italian Alps), is taken as a case study. It is noted that such a landslide impinges on the left abutment of an arch gravity dam and causes some closure of the arch, posing significant hazard to the dam safety and compromising reservoir operations.