Based On Risk Management Theory Stope Roof Fall Accident Analysis Spalling

Casualties and property losses are always brought by the unstable ore-rock emerged during the process of underground mining.Roof fall nicking accident is one kind of dangerous accidents with the highest accident rate among all the accidents happened at underground mines. So that, it’s always been a unpreventable problem persecuting the work safety.There are various mining methods and crafts in non-coal mine. The miners always work in the exposure stope for a longtime with the downhole rock drill which are used in most of the mining methods. The roof fall nicking accident happens a lot in the shallow mining slop.Based on the risk management theory, the way and reasons causing roof fall nicking accident in stop of Dahongshan Iron Mine where the iron mined in short-hole pillar and stall method are discussed in this paper. The analysis and evaluation on roof fall nicking accident are also made by a method integrating qualitative analysis with quantitative analysis. Some measures are correspondingly proposed to provide references for preventing accidents in short-hole pillar stop.The structure of the paper is as follows.(1)First, starting from the unsafe state of object and the people’s unsafe behavior, a system identification about the reasons leading to roof fall nicking accident is made based on the orbit intersecting theory and risk management theory.(2)Second, according to ETA, event tree about roof fall nicking accident is built by listing the causes of the accident. The Success-Tree is also built to determine the minimal radius set. The accident causes and the incidence of each cause to the top event are clear after the qualitative analysis on the structure importance of each elementary event.(3)Third, with FLAC-3D, the stress state, displacement and plasticity areal distribution of the worked-out stope is analyzed in accordance with result quantitative analysis of simulation on the short-hole pillar stop and the probability of large-area inbreak are well-founded analyzed. (4)Then, with LECD and Semi-quantitative analysis method, the Danger (the risk grade of miner working in the short-hole stop) is computed by valuing the L (likely hood) and C (consequence).(5)The last but not the least, considering the results of risk identification and risk analysis, four hierarchical risk control measures, that is, preventability, maintainability, usualness and complementariness, are put forward in accordance with principle of risk control by different level which provides references and basis for the mine safety management.