Study on Features and Genetic Mechanism of Debris-Bedrock Interface Landslide

The debris-bedrock interface landslides are widely distributed in the southwest and northwest region of China, but the features and genetic mechanism are not revealed thoroughly in the existing researches. On the basis of analyzing the futures of debris-bedrock interface landslides from literatures and the potential geological disasters investigation in Langao County, Shaanxi Province, this paper generalized the features of debris-bedrock interface landslides. According to laboratory tests results, the physical and mechanical properties of soil-rock mixture materials and rock-soil interface are discussed. It is found that the soil-bedrock interface is the weak structural plane which leads to the debris-bedrock interface landslide by comparison the strength between soil-rock mixture materials and soil-rock interface. Taking the Zushimiao landslide in Langao County which is a typical debris-bedrock landslide, the genetic mechanism is revealed based on site investigation, laboratory test and numerical simulations. It is thought that: the soil-bedrock interface as weak structural plane is controlling factor, the surface water infiltrating and groundwater seeping are triggering factors, and the debris-bedrock interface landslides occurred by combination of the two factors.