ABSTRACT
Slope failures have occurred frequently due to heavy rains. Causes of the failures are considered as reduction of strength due to rise in pore pressure and increase in the degree of saturation, and increase of self-weight due to water absorption. However, the detailed failure mechanism has not been elucidated. To elucidate the mechanism, this study conducted deformation and failure simulations of unsaturated slopes in rainfall model tests using a soil-water-air coupled elastoplastic finite deformation analysis code considering inertia force. As a result, we succeed in reproducing the deformation-to-failure behavior of the model slope due to rainfall infiltration. The soil element on the slip surface exhibits “softening behavior with plastic volume expansion” above the critical state line in p’ – q skeleton stress space. In addition, we reproduce deformation and failure patterns according to rainfall intensity.
