Use of a genetic algorithm to perform reliability analysis of unsaturated soil slopes

This paper describes the development of a probabilistic design approach to analyse the stability of unsaturated soil slopes. Instability of unsaturated soil slopes is caused by the downwards progression of a wetting front, which reduces the near-surface suctions, increases the weight of soil in the failure zone and reduces the soil strength. Assuming the slip surface forms parallel to the slope surface (at a depth equal to the wetting front depth) the probability of failure is determined in this paper through the reliability index determined using a computationally efficient genetic algorithm method.