ABSTRACT
This chapter discusses the Hitotsu-minesawa landslide, which was a large-scale rockslide that occurred on the ridge topography following the Niigata Chuetsu Earthquake in 2004, and reviews the relationship between the behavior of mountain slopes and the occurrence of landslides during earthquakes based on seismic response analysis using three-dimensional dynamic elasto-plastic FEM. Three-dimensional dynamic response analysis using a simple cyclic loading model that takes into account the shear strength and dynamic deformation characteristics of soil was conducted and revealed that high horizontal acceleration occurred on the mountain tops and high shear stress occurred in the valleys. The landslide that occurred at Hitotsu-minesawa transversely severed a ridge protruding west to westsouthwest. The seismic response analysis using dynamic elastoplastic FEM revealed that high horizontal acceleration and displacement occurred at salient topography such as at the head of the ridge and that, on the other hand, the large shear force influenced the stream part.
