Field model experiments to determine mechanisms of rainstorm-induced shallow landslides in the Feiyunjiang River basin, China

Abstract This paper investigates rainfall infiltration processes and the failure mechanisms of slopes in the Feiyunjiang River basin. Field model experiments were conducted on a selected residual soil slope next to the Fuao landslide, which was about 30 m long and 25 m wide, and failed along the interface between soil and bedrock during typhoon Megi. The results indicated that rainfall infiltration over the slope surface had little impact on pore water pressure and deformation of the slope, while the coupled action of slope surface infiltration and preferential infiltration through an artificial ditch at the back of the slope caused rapid saturation near the interface between the residual soil and bedrock, resulting in significant displacement along the interface. Other preferential infiltration channels on slopes in the Feiyunjiang River basin include tension cracks, water impoundment and intrusive dykes and their weathered layers. The conclusions derived from this study are helpful in understanding rainstorm-induced soil landslides in the Feiyunjiang River basin in China, and possibly in other similar slope settings under comparable climate conditions.