Earthquake and rainfall are two major disasters in a lot of mountainous areas in the world. Previous studies have found that despite earthquake-induced cracks on the slope surface, the slopes could remain stable after earthquake. However, it was the post-earthquake rainfall that led to the final failure of those slopes. The findings suggested the detrimental effect of earthquake-induced cracks on the slope stability during rainfall, but the detailed study of the mechanism has not yet carried out. In order to investigate the behavior of slopes with earthquake-induced cracks under rainfall, this study carried out a series of centrifuge tests on unsaturated slopes subjected to earthquake and rainfall. The slope models were placed on the shaking table in the geotechnical centrifuge, where the earthquake was simulated by the excited shaking and the rainfall was simulated by small water droplets produced from nozzles above. Test results demonstrated that earthquake-induced cracks occurred near the shoulder of the slope and the presence of these cracks significantly affected the deformation and failure of slope during the following rainfall. The failure pattern of the slope subjected to post-earthquake rainfall was found considerably different from that of the slope subjected to rainfall without previous earthquake. For the slope with earthquake-induced cracks, rainfall accelerated the failure of the slope, resulting in the rapid and massive landslide.

Centrifuge test,Slope,Deformation,Failure,Earthquake,Rainfall