针对某金属矿长期处于大规模充填体下开采的现状,对-300 m各盘区回采期间的稳定性进行了数值模拟,分析不同方案的采场开采过程中顶板应力、位移等指标的变化规律,并综合分析比较了各方案的回采安全性与经济效益。分析结果表明:将E101采场作为永久性连续盘区时,回采至中期采场顶板处产生1.14 MPa的最大拉应力和75 mm的最大位移;开采后期采场顶板处产生2.30 MPa的最大拉应力和92 mm的最大位移;开采后期采场顶板的抗拉安全系数为1.53;整个顶板岩体稳定性较好,确定将E101作为盘区永久矿柱。根据盘区永久矿柱的位置,提出了4种盘区回采顺序,分析比较不同开采方案的顶板、直接顶板、矿壁及充填体稳定性,确定了从矿体中央连续永久盘区矿柱E101采场向两侧分盘区开采的回采顺序。
Based on the present mining situation that a metallic ore under the large-scale backfill body has been mined for a long period of time,numerical simulation on the stability of the stope during mining process at-300 m of each panel zone was made to analyze the changing rules of the roof stress,displacement and other indicators during mining process and comprehensively compare the recovery safety and economic benefits of each program. The results show that: when E101 stope is considered as a permanent consecutive penal pillar,the maximum tensile stress of 1. 14 MPa and maximum displacement of 75 mm are generated at roof in the middle period; the maximum tensile stress of 2. 30 MPa and maximum displacement of 92 mm are generated at the end of mining,meanwhile the roof tensile safety factor is 1. 53. The entire roof rock stability is good,so E101 panel is determined as the permanent pillar. According to the position of the permanent penal pillar,four panel stoping sequences are proposed. After comparing the roof stability,immediate roof,wall and backfill of different mining plan,the mining sequence from the permanent pillar stopes E101 ly extending to two side is determined.