地下转露天开采条件下某露天矿高陡边坡稳定性分析

某露天矿为地下转露天开采,在复杂工程地质条件和原地下采空区的综合影响下,露天边坡极易发生塌陷、台阶失稳等灾害,严重威胁露天矿安全生产。为研究地下转露天开采条件下某露天矿高陡边坡的岩体变形破坏规律,结合实际地质条件,利用Dimine-Midas/GTS NX耦合建立大型露天矿三维工程地质模型,并进行稳定性计算分析。分析结果表明:地下采空区顶板变形量较小,对露天矿边坡影响不大;南部强风化岩区域边坡位移量较大,边坡有向外"滑动"的趋势;开挖至-180m平台时,边坡安全系数降至临界值,并出现塑性区开始贯通坡脚现象;综合分析得出该矿山开采的临界水平为-180m平台。通过对该实例工程边坡的破坏机制分析,揭示了边坡变形破坏的主要因素,并为后续边坡治理提供理论指导。

Stability analysis of high and steep slope in an open-pit mine under the condition of transferring from underground into open pit mining

An open pit mine is turned underground to open-pit mining. Under the comprehensive influence of complex engineering geological conditions and historical goaf, the open-pit slope is prone to collapse, step instability and other disasters, which seriously threatens the safety production of open-pit mine. In order to study the deformation and failure law of high and steep slope rock mass in an open-pit mine, a three-dimensional engineering geological model of large open-pit mine was established by using Dimine-Midas/GTS NX coupling method and its stability was calculated and analyzed. The results show that the roof deformation of underground mined-out area is small and has little effect on the slope of open pit mine; the slope displacement in south area of strong weathered rock is large, and the slope has the tendency of "sliding" outward; when excavated to -180m platform, the slope safety factor drops to the critical value, and the plastic zone begins to penetrate the foot of slope. It is concluded that the critical level of mining is -180m platform. Through the analysis of the failure mechanism of the slope, the main factors of the slope deformation and failure are revealed, and the theoretical guidance for the subsequent slope treatment is provided.