Slope stability analysis of expansive soil considering the effect of rainfall

Slope stability of expansive soil is analyzed according to rainfall intensities, rain patterns and saturated hydraulic conductivity by the theory of saturated-unsaturated seepage. The results show: 1) the slope stability decreased with the increase of the rainfall intensities; 2) the weathered surface layer has a great influence to slope stability because its high permeability is one of the underlying reasons why the expansive soil slope is prone to have shallow landslides; 3) rainfall concentrated in earlier stage is against the slope stability, while it is one of the outside reasons why the toe of expansive soil slop is most likely to be landslide that the water is pounding at the toe area during rainstorm.