Centrifuge modeling of failure behaviors of sandy slope caused by gravity, rainfall, and base shaking

This study focused on slope stability behaviors under different conditions, including gravity, rainfall, and earthquake. The slope models were prepared by mixing sand (80%) and clay (kaolinite, 20%) and compacting at optimum water content. Under the gravitational condition, the model tests were performed with three different directions of a gravel layer embedded into the slope. During the test, the artificial acceleration was gradually increased until slope failure occurred to observe the slope behaviors under rainfall and earthquake. The results indicated that the direction of the gravel layer affected the distribution of water content. Additionally, it was found that the inclination angle was a key factor influencing slope stability. Rainfall intensity played an important role in infiltration water. With regard to the failure wedge, among the three conditions examined, the earthquake condition generated the most significant effect on slope stability. Herein, for evaluating the stability of slopes, the Bishop's method incorporating an inclination angle of a gravel layer and apparent cohesion is introduced.