Mechanisms Of Slope Instability And The Starting Of Debris-Flow Under The Complex Function Of Rainfall And Earthquake

Debris flow is a common mountain natural disaster, which is attention by people for its sudden and strong destructive power. Earthquakes are common in our country, and after the earthquake with rainfall often cause debris flow hazards. On May 12, 2008, wenchuan county, sichuan province occurred the 8.0-magnitude earthquake.After the earthquake, the county suffered rainstorm, influence by the heavy rain, the losed eluvial and stack layers slump in large areas,at last,caused this sudden debris flow.Therefore, it is great significance to study the starting mechanism of debris flow which caused by the complex function of earthquake and rainfall. This study also can f provide theoretical guidance to the disaster prevention and mitigation of earthquake.In this paper, regard the debris flow area soil in wei jia gully of the HouShan middle school in old beichuan as the research object. Through the indoor dynamic triaxial test to study the strength decay laws of the slope surface soil under the complex function of rainfall and earthquake, explore the starting mechanism of debris flowunder the complex function of earthquake and rainfall. Take the slope in wei jia gully as an example,through FLAC numerical simulation to study the effect of slope angle, raininess, soil property, initial soil moisture content and soil uniformity to slope instability and the starting of debris. Further, study the starting mechanism of debris-flow caused by instability of slope accumulation body under rainfall,first through the indoor artificial rainfall testing to study the confluence situation and the starting mechanism of debris-flow caused by instability of slope accumulation body under rainfall,further using the particle flow to study the starting process of debris flow caused by the increase of moisture content to saturation of slope accumulation body under rainfall preliminarily.