Study on evaluation of behavior for slope stability and failure during earthquake for using seismic risk of NPP

摘要

Fukushima Daiichi nuclear power plant lost the external power source by collapse of the power transmission steel tower which originated in the slope collapse by the 2011 off the Pacific coast of Tohoku Earthquake. It is important to evaluate the influence of the slope collapse behavior on a facility in a nuclear power plant, although emergency power was also lost and it resulted in the major accident by tsunami, when performing the risk assessment of a nuclear power plant. As for the effect of slope, it is also important to perform stability assessment of a slope. In order to evaluate not only the stability assessment but also the collapse behavior, the seamless evaluation from the nonlinear behavior to the collapse behavior is required. MPM is a kind of a particle method and is useful to evaluate the behavior numerically. A series of shaking table tests for the slope models of various scales were carried out to verify the usefulness, and comparison with the result was performed. As the simulations by MPM, a extensive soil deformation based on the elasto-plastic constitutive law was considered. Here, the super/subloading yield surface Cam-clay model (SYS Cam-clay model) was adopted. As a result, it is found that the behaviors obtained numerically by the MPM are similar to the experimental behaviors.