The Gob Disaster Risk Fuzzy Comprehensive Evaluation

These days, rib fall, roof fall, water inrush, earthquake, rock burst, ground collapse, ground subside, ground crack caused by goaf of underground mining as well as their induced disaster such as landslide, debris flow, surface vegetation demolish etc. which have been the major disaster in underground mine, have resulted in momentous personnel casualty and equipment accident and aroused government and enterprise's intense recognition. Aiming at large amount of unsettled goaf formed by underground Open-stope mining process in Copper filiale of Dabaoshan mining Ltd., this paper put up systematic and deep research to their safety and stability. Main contents are as follows:1. Based on the data offered by on spot technique department and the vast on spot inquisition of underground goaf within mining area which tend towards about 2000m long, we carried through statistical analysis and got distributing density, geometry size, space shape of goaf and distributing status of goaf masses, moreover analyzed past years' goaf disaster accident of this mine.2. We analyzed the breakage mechanism and breakage type of surrounding rock from the view of rock mechanics. Main factors of goaf stability were obtained by analyzing four affecting matters containing geology, hydrology, environment and geometry parameter of goaf.3. Fuzzy integrated assessing theory was used in hard rock mine goaf for the first time and multifactor assessing model for goaf hazard degree was also constituted. We proposed goaf hazard degree index, adopted multi-proportional pairwise comparative method to ascertain the weight of assessing index factor, and four-valued logic zoning method to ascertain subordination function and grade standard. Thereby quantitative analysis of underground goaf disaster hazard degree in Dabaoshan was realized, then 37 statistical goaf were compartmentalized to be extremely high hazard degree, high hazard degree, common hazard degree and low hazard degree, space location and distributing character of various goaf hazard degree were also indicated.4. FTA model of goaf disaster was constructed, the basic eventsleading to accident were found according to analyzing of goaf disaster, and the structure importance of each basic envents were calculated by fault tree qualitative analysis, finally, the possible least path leading to accident and basic approaches for accident prevention were analyzed.5. Stability of goaf 3# and 6§ with high hazard degree were calculated by three-dimension software ANSYS to obtain the main position of breakage.6. Idiographic management measures with feasible technology and reasonable economy were put forward respectively for various hazard degree goaf to offer the leading theory basis and technical instruction.