Metal Mine Gob Hazard Identification And Risk Assessment Studies

Mined-out areas are caused by the exploration of underground mine.Because of the difference of mining method and management, its shapesand structures could be of various kinds, which could result in disasterssuch as rib fall, roof fall, mine earthquake, rock burst, water inrush, groundcollapse, ground subside and crack. At present, the mined-out area hasbeen one of main disaster sources of underground mine. Based on thestudy of documents both at home and abroad, the study progress, theachievements, existing problems and development were analyzed andsummarized directions in this paper, and based on System EngineeringTheory, Risk Assessment, Theory Reliability Theory, and Principles ofEconomics, hazard identification and risk assessment in mined-out areawere studied.Firstly, the relevant concepts of risk assessment in mined-out areawere identified and defined. Through the analysis of the composition ofrisk assessment, framework model of risk assessment system wasconstructed, and meanwhile, the process of hazard identification and riskassessment were made clear.Secondly, a theoretical analysis of mechanical state and stability ofthe rock in mined-out area was made, and with the help of fault treeanalysis, the accident-caused mechanism of roof fall in mined-out area wasanalyzed. The main factors relating the safety of mined-out area wereknown, and the hazards types and influencing scope of mined-out areawere summed up.Thirdly, by the study and analysis of hazard, vulnerability and damagein mined-out area, and by the adoption of energy conservation and transfertheory, the energy transfer accidents cause model was established, bywhich the hazard of mined-out area could be quantitatively analyzed. Inaddition, on the basis of hazard analysis, we made a value evaluation and asocial and economical vulnerability analysis within its influencing scopeand the calculation of damage losses in mined-out area, so vulnerabilityand damage were worked out. And by doing this, the risk assessmentsystem of mined-out area was established, and the corresponding risk control measures are made through risk degree got in risk assessment. Onthe mentioned above, a fairly perfect theory and methodology of hazardidentification and risk assessment of underground mined-out area wereformed in this paper.With the theory and methods of risk assessment above, the riskassessment of mined-out area No. 42 of R-pit of copper ore No.92 were incoincidence with the actual situation.