Study of the stability analysis of rock slopes on the alps

The paper reports the described methodology applied to a case study of stability evaluation of a rock slope at high elevation (Monte Bianco) where instability phenomena where observed. Stability analysis were performed using both Limit Equilibrium Method (LEM) and Distinct Element Method (DEM) in 3Dimensional field based on accurate non contact surveys. The surveys are supported and validated by traditional in situ measurements of the discontinuity orientation and other rock mass features. The required discontinuity shear strength has been validated by direct shear tests performed in laboratory on specimens taken on the slope. Furthermore, the paper presents some considerations on the influence of climate changes on the rock mechanical features and examines the effect of temperature variation on the stability conditions of rock slopes; this is done by means of several parametrical analysis of the Aguille Marbrèe rock outcrop carried out modifying the rock discontinuity saturation, persistence and frequency, shear strength etc.. These analysis are showing how a different water regime in the rock mass, caused by climate variation, can strongly influence the stability condition of the slope; on the other hand, the DEM analysis are used to better understand the complex and progressive instability phenomenon that was observed on site. The comparison between the shape of the unstable blocks and their volume as computed by DEM and those measured on site at the base of the slope, validate the DEM results.