Design of large cuttings in jointed rock

The article presents a stability study on a very high cutting in a granitic gneiss, as part of the construction of a bypass in the French Pyrenees. The preliminary study highlighted questions as to the most appropriate method of designing the rock cuts, as such methods are not standardized in France. A temporary stop in the roadworks allowed a second study to be carried out based on a statistical analysis of the discontinuities of the site and better-developed modeling tools, including Resoblok. A comparative analysis of these methods and their results in terms of bolt sizing is presented, taking into account the difficulty of use of each method.