Evaluation approach for long term stability of expansive soil slope

Groundwater level usually changes with the rainfall or some other environmental factors, which may induce alternate wetting and drying to part of a slope. This is especially harmful for the stability of an expansive soil slope. Upper bound limit analysis on slope stability is only applicable for proportional loading. In case of alternate loading and unloading, a shakedown analysis is necessary for its long term safety evaluation. In this paper, an upper bound shakedown analysis based on strong version of Koiter's theorem is presented to analyze slope stability which subjected to such an alternate load. Safety factor is defined by shear strength reduction of the materials. A simple example is adopted to verify the availability of this method.