A modified geotechnical simulation model for landslide motion

Based on the previous work of geotechnical simulation on the motion of landslides conducted by Sassa (1988), a modification is made on the shear resistance item, and the simulation model is improved. The landslides are considered to be with two-layer structure, i.e., debris layer and sliding zone. After sliding for a certain distance, the soil at sliding zone reaches steady state, and the shear resistance mobilizes to the minimum value. In the sliding process, the thickness of the debris layer always changes its thickness, and results in the change of the apparent friction angle. Based on this consideration, changing model of apparent friction coefficient is built, and then applied to Sassa’s simulation model. Finally, a case study is carried out on the Sumikawa landslide occurred in Akita Prefecture in 1997, and the simulation results of areal prediction show a good correspondence to the deposit distribution of the actual landslide.