Earthquake-Triggered Violent Landslides

摘要

Activated by the M_w 7 1995 Kobe Earthquake, the Nikawa landslide involved about 100 m displacement of a large wedge of an originally rather mild slope. The surprisingly large and rapid in nature runoff of the soil mass, motivated several researchers to interpret the sliding process. There is still no consensus as to which were the actual causes of those two catastrophic events. The goal of the paper is to study: (i) the landslide triggering and propagation, and (ii) the mechanism of material softening inside the shear band responsible for the accelerating movement of the two slides. To this, a model is utilised considering two mechanically coupled substructures: (a) the accelerating deformable body of the slide, and (b) the rapidly deforming shear band at the base of the slide. It combines features of an extended Savage-Hutter approach, with (a) Mohr-Coulomb failure criteria, and (b) Bouc-Wen hysteretic stress-strain relationship, and exploits the concept of grain crushing-induced instability. The method successfully interprets the studied landslide.