Stability of Rock Slopes, A Three-Dimensional Study

The stability of a rock slope or foundation is analyzed in terms of sliding along geological surfaces of separation. The proposed method considers rock volumes limited by three internal plane surfaces and the natural ground surface. The applied forces are weight, external loads, pore pressure. The resistance to sliding is due to friction on the internal planes of separation. The equilibrium is three-dimensional. Geometry, kinematics, and statics are first described, assuming that movement can only be translation. The traces of forces and planes on a unit sphere are used for an exhaustive discussion of the problem. It is thus possible to compare the weight of the different parameters covering equilibrium, a comparison which has more meaning to the engineer than the computation of a so-called factor of safety.