Stability analysis of existing slopes considering uncertainty

This paper describes a technique that can be used to handle soil parameter uncertainty in the stability analysis of slopes. The basic idea of this technique, called the vertex method, is to `discretize' uncertain soil parameters, expressed as fuzzy numbers, into a set of intervals. By replacing fuzzy numbers with intervals, the analysis with uncertain parameters reduces to a series of interval analyses that use only conventional mathematics. This approach, capable of handling parameter uncertainty, is deterministic, rather than probabilistic. PCSTABL, a popular PC-based computer program for slope stability analysis is used in conjunction with the vertex method to analyze slopes in the present study. A case study is presented to demonstrate this approach. The presented methodology is shown to be effective in handling parameter uncertainty in the stability analysis of slopes.