Research And Application On Discrimination Method Of Mined-out Area Stability In Underground Metal Mine

Abstract:The stability of mined-out area in underground metal mine has a big effect on the normal operation of mine enterprise and the recovery of mineral resources. Research work on goaf stability has the important practical significance. According to the multiformity, complexity and fuzziness of mined-out area evaluation system of underground metal mine, relying on the National "Twelfth Five-Year" Plan for Science&Technology Support "three-dimensional laser scanning spatial information modeling and dynamic monitoring goaf technology research"(2012BAK09B02-05) and combining the project practice of Fankou Pb-Zn Mine, experimental study and theoretical analysis methods were used to the stability analysis of underground metal mines goaf, aiming to discriminate the stability of mined-out area from the global and local levels.The main research contents and achievements are as follows:(1) Stability Analysis indexes and hierarchy process analysis system of mined-out area were set based on theoretical analysis of failure mechanism and instability of goaf surrounding rock combining with the engineering practice of Fankou Lead zinc mine. And the weight determination of each index through IFAHP method lays the foundation for goaf stability analysis.(2) The improved TOPSIS method which is suitable for stability multi-attribute analysis of mined-out area was formed base on analysis its shortcomings and causes of classic TOPSIS method.(1)Closeness degree algorithm was improved and introduced auxiliary reference distance, thus, indiscernibility of TOPSIS method was avoided.(2) Change of ideal point caused by change of projects amount was avoid by absolute ideal point, and the reverse phenomenon of TOPSIS was improved, and calculate the positive and negative ideal solution of goaf stability multi attribute analysis OPSIS in underground metal mines.(3) Grade division and analysis quantization index on mined-out area stability achieved based on closeness degree calculated by five groups of objects which formed through different instability degree interval threshold value of mined-out area analysis index and mined-out area stability was discriminated by the improved TOPSIS method.(3) Qualitative discrimination index of the goaf was described by intuitionistic fuzzy numbers of the interval value. Operation of the coexistence of the real and intuitionistic fuzzy numbers of the interval value was solved by citing the score function to make the mean transformation of intuitionistic fuzzy numbers of the interval value. The improved TOPSIS was used to make stability analysis of the ten metal ore goafs. And the practice has proved the measure has applicability and engineering application.(4) The research of realization of point safety factors under the common used principle like Mohr-Coulomb and Mohr-Coulomb was realized by FISH language. Goaf2#,4#having been made the stability analyze of Fankou metal ore were researched to make numerical analysis and point safety coefficients. The correctness of the TOPISIS stability analysis was tested by analyzing displacement and stress analysis in the plastic zone. Point safety coefficient within the scope of the investigation was counted. Local security trends and minimum value were presented by point safety coefficient curve of the gob roof and both sides of the boundary line to realize the further analyze of the stability of mined area from the local level.