An Experimental Study on Slope Failure Caused by Rainfall

On the mechanism of failure at the foot of slope

Abstract

Slope failure is occured by seepage water and often begins from the partial failure. We investigated experimentally the relation between the hydraulic gradient of ground water and the partial failure at the foot of the slope. An experimental equipment has a length of 3 meters, a width of 1.5 meters and a depth of 0.3 meters. It is supported at the angle of 30 degrees. Soil was uniformly filled up in it. The rainfall was supplied on it with the intensity of 50mm/h. The ground water of four different hydraulic gradient was occured by changing drainage conditions at the lower end of the equipment.
The results and comments are summarized as follows.
1) The partial failure at the foot of the slope was caused by the seeping of the ground water, and the more the ground water had the steep hydraulic gradient, the more the partial failure extend rapidly upper part.
2) It was found that the ground water affecting the partial failure at the foot of the slope could be theoretically approached by applying Dupuit-Forchheimer assumption to the inclined impermeable layer.