Centrifuge Model Simulations of Rainfall-Induced Slope Instability

Abstract

This study focused on landslides resulting from heavy precipitation, such as rainfall from hurricanes. A series of centrifuge model simulations were performed with reference to a landslide that occurred during Typhoon Nabi in Japan in 2005. The procedures of simulation on the slope using a sand-clay soil mixture were illustrated. The rainfall event was simulated by applying precipitation in increments to the slope surface until it exceeded that of the field measurements. The instability was examined using an infinite slope analysis, and the mechanism of rainfall-induced failure was discussed. For this particular study, the results showed that incremental rainfall of less than 200 mm led to local failures, whereas total accumulation of 400 mm resulted in a global slope failure. A reduction in apparent cohesion in the soil combined with an increase in pore pressure because of infiltration was responsible for the slope instability during rainfall.