Numerical Modelling of Permafrost Degradation Effects on Rock Slopes

Rockfalls and rockslides are being observed with increased frequency in high mountains during last decades. Permafrost degradation, driven by global warming, is considered to be the main triggering factor. This paper describes a series of Distinct Element simulations of a selected rock face, where the presence of ice in joints is taken into consideration. These simulations are part of a wider multi-scale approach to modelling of potentially rock slopes. Previous research at the material scale (ice and frozen soil) allowed defining an original failure criterion for continuous and discontinuous rock joints filled with ice. This criterion is now included in large scale DEM model of punta Gnifetti (4554 m asl - Monte Rosa massif) in order to reproducing the actual configuration through back-analysis based on geomechanical investigation, and assessing evolutionary scenarios driven by the increase of persistence and of temperature. Relevant numerical issues, regarding boundary conditions and model generation are preliminary discussed, as well.