| After mining for years,the jiaojia gold mine mainly possesses those problems at present,for example,small drift size of the upward drift stoping with backfilling,low production efficiency and poor mining safety.To solve this major production technology problem,the method of expanding drift size with anchor cable support was come up with through consulting lots of related reference at home and abroad and combining with the actual situation of the jiaojia gold mine.the drift stability was analysed on the different condition of directly expanding drift size and doing with the anchor cable support,which demonstrated the appropriate size and the feasibility of expanding drift by the method of numerical simulation.The test stope was Selected to make industrial field test,and the test results were summarized and analyzed.The method was put forward based on the combination of AHP and fuzzy comprehensive evaluation,which make the safety evaluation on the stope roof after expanding drift size to make sure that the mining was economic and efficient The major research results and conclusions are as follow:1) According to detailed investigation and analysis,and read domestic and foreign reference,the method of expanding the drift size by anchor cable support was put forward,which could make sure the safety of mining and improve mine production efficiency.2) The stability was analysed by numerical simulation software ANSYS on the condition of directly expanding drift size and doing with anchor cable support.the results showed that the stope roof was stable when the drift was first-step mined.the tensile safety factor was respectively 1.34 and 2.77 when the drift was second-step mined and the span was expanded to 3.5m,and the tensile safety factor was respectively 0.75 and 1.63 when the drift was second-step mined and the span was expanded to 4m.in contrast,it could be seen that the tensile safety factor of the roof had been significantly improved and the roof was stable.therefore,the span of drift would be expanded to 4m when the stope roof was supported by anchor cable.3) The 81124 stope was selected for the test stope in -270m middle part,in which it done the industrial field test expanding the span of drift by anchor cable support.the drawing force of the anchor cables had been installed were detacted,which showed that the drawing force met the design requirements and the quality was good.according to the statistics,the efficiency of mining and the production capacity improved above 30% after the drift size was expanded,which brought 15 million ton profits every one year for Jiaojia gold mine and the economic efficency was very obvious.4) The stope roof stability was evaluated by the method combining AHP with fuzzy comprehensive evaluation.the weight vector of all index factors was determined according to Analytic Hierarchy Process.comprehension evaluation vector of stope roof stability determined by fuzzy comprehensive evalution was [0.0004 0.7607 0.2208 0.0115 0.0067].therefore,according to the maximum membership principle,the stope roof was stable after the drift was expanded,which achieved better results. |
