深凹露天矿末期扩帮强化开采安全防控关键技术研究

Study on the Key Technologies of Safety Prevention and Control in the Slope Expansion and Strengthening Mining at the Later Stage in Deep Open Pit Mine

为了安全回采深凹露天矿山开采末期部分挂帮矿石,以山达克铜金矿深部扩帮工程为研究背景,采用简化Bishop法与Morgen-Prince法研究了扩帮开采工程边坡稳定性状况,并运用蒙特卡罗法分析了边坡破坏概率,分析了扩帮工程的安全风险,建立了扩帮开采深层微震+浅层三维激光扫描边坡稳定性立体在线监测系统,研究了扩帮开采过程中边坡岩体微宏观变形演化机理。工程实践表明:扩帮开采边坡安全风险分析与边坡立体在线监测结果具有高度的耦合性和一致性,通过扩帮强化开采,矿山服务年限延长了4 a,直接回采矿石量达502.93万t,印证了研究结果的合理性,同时也为类似矿山末期扩帮强化开采提供了示范工程。

In order to safely recover parts of the hanging wall ores at the later mining stage in deep open pit mines,taking the deep slope expansion project of Shandak Copper and Gold Mine as the research background,the slope stability of the slope expansion project was studied by simplified Bishop method and Morgen Prince method,and the slope failure probability was analyzed by Monte Carlo method.The safety risk of the slope expansion project was analyzed.A three-dimensional on-line monitoring system combining deep microseism with shallow three-dimensional laser scanning for slope stability was established,and the evolution mechanism of micro and macro deformation of slope rock mass in the process of slope expansion and strengthening mining was studied.The engineering practice shows that the slope safety risk analysis and the three-dimensional on-line monitoring results of the slope are highly coupled and consistent.The service life of the mine has been extended by 4 years and the mass of direct recovered ores has reached 5.0293 million tons,which confirms the rationality of the research results,and also provides a demonstration project for the slope expansion and strengthening mining at the late stage in similar mines.