2012 Volume 128 Issue 7 Pages 463-470
In recent years, localized torrential rain caused by abnormal weather happened frequently, which induced increasing slop collapses in Japan. Failure could happen in some normally stable slopes due to the seepage of rainwater in the ground. In this study, a model experiment investigating the slope failure caused by water seepage was reproduced in numerical simulation by using the coupled stress-flow method. The failure mechanism of slope induced by the increase of underground water level and decrease of effective stress was investigated through the test and simulation results. Case study was carried out by using numerical simulation to estimate the relation of the variation of pore pressure and the distribution of shear strain. Numerical simulation was furthermore applied to a slope that collapsed on July, 2009 in Kyushu Island during the torrential rain to verify the proposed numerical approach. The numerical simulation results agree well with the model experiment and field investigation results. Based on the results of slope deformation and stability analyses taking into account the change in water pressure and cohesive strength, it shows that the excessive pore pressure increases dramatically especially underneath the surface of slope where failure will happen.
