FLOW DOWN AND COLLISION BEHAVIOR OF UNSATURATED SOIL USING DISCRETE ELEMENT METHOD WITH COHESION

Abstract

Slope failures may occur under unsaturated conditions before the surface soil reaches saturation due to rainfall. Countermeasures may be installed at the slope toe to prevent the sediment from flowing into the road or railway. In order to select an economic countermeasure, it is necessary to clarify the mechanism of flow down and the generation mechanism of impact force of unsaturated soil. This study aims to elucidate these mechanism not only by experiment but also by numerical simulation.

In this paper, the applicability of the DEM simulation which introduced the simple cohesion model considering the effect of cohesion to the slope flow and collision behavior of unsaturated soil was examined. As a result, it was shown that the relationship between the condition of the collapsed soil and the maximum impact force obtained by the impact experiment can be roughly reproduced by proposed DEM model. In addition, numerical experiments were conducted on the assumption of full scale, and it was shown that the collapsed soil deposited on the wall may play a role as a shock absorber for the continuing impact of the collapsed soil.