Abstract
In this study, we performed the box shear test and the cyclic tri-axial test in order to make clear the mechanism of slope failures due to rainfalls after the earthquake. As a result, the cohesion of the soil decreased by the cyclic loading and the degree of saturation rising with the submergence. These mean that the soil shear strength was decreased because the skeletal structure of the soil was destroyed by the seismic motion and decreasing of the shear strength was generated additionally by increasing of the degree of saturation due to the rainfall after the earthquake. This is one of mechanism that many slope failures occurred by rainfalls after the Kobe earthquake.
