Three-dimensional ridge collapse mechanism for narrow soil slopes

Three-dimensional analysis of stability is carried out for slopes with the failure mechanism confined to a narrow space. A curvilinear cone failure surface is modified by removing a slice from its central portion, to make the failure mechanism fit in the narrow space. The resulting surface is no longer smooth, and it is referred to as the ridge mechanism for a distinct ridge in the failure surface. The analysis of narrow slopes based on the ridge mechanism appears to yield lower stability factors than the mechanisms used in geotechnical engineering thus far. Kinematic limit analysis utilized in calculations provides an upper bound to the true stability factor solution, hence the newly proposed mechanism delivers a more accurate solution.