This paper presented a case history of a plane-torsion rockslide occurring on an oblique bankslope where the dip direction of foliated rocks intersects the dip direction of the slope. Because of the varietyof favorable bounding discontinuities,its movement is accompanied by counterclockwise rotation along a fault-controlled plane that dips moderately towards the valley. In this case the local restriction of sliding arisingfrom the locked flank causes a slender rock mass to spin about a hinge at the point where sliding is impeded.As a result,its failure mode can be generalized as a rock cantilever. By means of the Rayleigh-Ritz energymethod,an equation of elastic deflection-load of the rock cantilever with cracks is established,and its ultimatebeating capacity is established using the criterion of stress intensity factors in fracture mechanics. Consequently,a criterion for the stability of the rockslide is deduced. The criterion is proved to be feasible in engineering design.
展开▼
