Research On Initiation Mechaniam And Risk Assessment Of Mine Debris Flow In Yinchang Gully Luding County Sichuan Province

Debris flow is a typical mountainous geological disaster. Due to the features of huge chunk, loose stacking, large porosity, rich slag and centralized accumulation place, the slag debris flow which is mostly caused by the illogical piling of the slag is usually serious harm, Though investigating the Yinchang gully’s mine debris flow, such as topographical conditions, material conditions and hydrogeological conditions, this paper investigates the starting conditions and the initiation mechanism of the mine debris flow preliminarily, and assesses its risks. The main contents and achievements are listed as follows:(1) Based on wild investigation, demonstrating the geological environment background of the Yinchang gully’s mine debris flow, including topography and geomorphology, formation lithology and mineral resources.(2) The analysis of initiational qualifications about Yinchang gully’s mine debris flow. Summarizing the initiation area, circulation area and accumulation area of debris flow; channel condition and water sources respectively. Analysesing the characteristics of different kinds of metrials and the corresponding dynamic reserves were assessed.(3) The research of the characteristics about Yinchang gully’s mine debris flow. The characteristics of channel erosion and deposition in different locations are identified. Analyses were conducted on the particle characteristics and stacking relationship of the debris. A comprehensive systems analysis and research about the triggering factor was also conducted in the aspect of engineering geology.(4) The mechanism of mine heap and the prognostication of its dynamic reserves. FLAC3D was used to analysis stress distribution and stability of slag accumulation body in natural and rainstorm conditions. PFC2D was used to simulate the whole process of deformation and failure about the slag accumulation body. Considering the result of its destruction and field investigations, the dynamic reserves of slag provenance was assessed.(5) Weighted mean of indicator value is used to assess the risk of Yinchang gully’s mine debris flow outbreak. Based on 4 essential conditions (geological, morphological, meteorological and historical),9 factors are used to establish the evaluation system.