ABSTRACT
An original field characterization protocol coupling stress measurements and acoustic logging in a borehole was conducted in order to improve site geomechanical properties and potential instability estimations. This chapter presents an overview of the research site and objectives, as well as some preliminary results collected from subsurface investigations and an assessment of the knowledge gained at this stage. Rockfall is a slope failure mechanism for which both the preparatory and triggering processes are poorly understood. The basal portion of the Pilot Site Laboratory is at an elevation of 900 m and the top of the slope culminates at an elevation of 2,254 m. At the end of 2005, a 19 metres deep sub-horizontal over-cored borehole was sunk in a compartment block of interest, underlying a large planar failure flagstone to measure stresses, obtain samples and run surveys for refined characterization of the rock fabric.
