A stochastic approach to rainfall-induced slope failure

This paper considers the influence of spatial variability of soil properties on the stability of an unsaturated soil slope during and antecedent to a rainfall event. With water tending to follow a rather tortuous flow path during the infiltration process, slope failures may occur locally due to loss in matric suction with increasing degree of saturation. An elasto-viscoplastic finite element program com bined with random field theory is used to analyse the influence of the heterogeneity of the subsoil, as characterised by the point and spatial statistics of the property values. Using a Monte Carlo framework, the results of multiple realisations have been evaluated in terms of reliability as a function of both global factor of safety and time.

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