EFFECTIVE STRESS ANALYSIS TO EARTHQUAKE-INDUCED COLLAPSIBLE LANDSLIDES

Abstract

 Earthquake-induced landslides on gentle slopes sometimes cause tremendous damage to human society. They are normally not designated as a steep slope area in danger of failure because of their gentle slopes. Characteristics of such a landslide have been studied by many researchers. However, failure mechanism, especially under dynamic condition, is fully unknown. Based on the field investigation and laboratory test results, the slope of Hanoki-daira in Fukushima Pref., where this type of landslide occurred in the 2011 Tohoku Earthquake, is modeled as one-dimensional FEM model to elucidate the failure mechanism. As a result, it indicates that the balance of shear stress before seismic motion acting and shear strength at slip surface is important for earthquake-induced landslides on gentle slopes.