Camille Perraudin: Characterization of Montset rock slope instability in Hérémence valley.

Camille Perraudin
Supervisor: Prof. Michel Jayboyedoff
Experts: Dr. Marc-Henri Derron, MSc. Dario Carrea

The study focuses on the characterization of Montset rock slope instability in Hérémence valley. The first part of the work aims to determine, on the basis of geomorphological and geometrical characteristics, what kind of instability is that of Montset, which at first looks like a Deep Seated Gravitational Slope Deformation. The next step is to determine its level of activity, i.e. if the movement can be measured and / or observed, and, if necessary, to locate them. Signs of activity, in terms of surface and deep instabilities are detected by field observations and also from the information obtained with LiDAR. This provides a series of measurements of high density accuracy for the creation of a point cloud of the topography. The detected instabilities are described and their susceptibility to failure is evaluated. A hazard map for rockfall in the study area has been created. Following this, a model of instability is constructed. This model incorporates field observations, displacement measurements, information from the geological map and subsurface data. These data were acquired during the visit of a hydraulic gallery underlying the eastern part of the Montset. Finally, based on the synthesis of information from the study, assumptions about the history of instability and the reasons that led to its development are proposed.