霍各庄南矿段地下开采中露天境界顶底帮稳定性分析

针对霍各庄矿区南矿段从露天开采转入地下开采时已有露天边帮的稳定性问题, 选取霍各庄矿区南矿段典型勘探线剖面处露天境界最终边帮建立了模型, 运用有限元强度折减法找到了已有露天边帮的潜在滑移面, 采用边坡稳定矢量分析法对该露天境界顶、底帮在各个工况下的稳定性状态进行了分析。分析表明:边坡稳定矢量分析法可同时求解露天境界顶、底帮在潜在滑移面方向的安全系数; 该矿段露天边帮在露天开采结束时状态稳定; 露天境界顶帮的安全系数随地下开采向下延伸不断变小, 并在地下开采首中段时产生失稳破坏; 整个地下开采过程中, 露天境界底帮的安全系数受采动影响较小, 边帮一直处于稳定状态。

Stability Analysis for the Top and Floor of Surface Boundary Slope at the Southern Corner of Huogezhuang Mine for Underground Mining

Due to the transition of open-pit mining to underground mining at the southern corner of Huogezhuang mining area, the ultimate pit slope at the cross section along the typical line of exploration was taken for modeling. Then, the potential sliding plane of existing open-pit slope was determined by using shear strength reduction finite element method, and the stability of the top and floor of surface boundary slope under different working conditions was analyzed with vector analysis method. Results show that the safety factor of the top and floor of surface boundary slope along the direction of potential sliding plane can be determined with the vector analysis method. The open-pit slope at the southern corner will be kept stable at the finish of surface mining, while the safety factor of the pit top tends to be smaller as the underground mining advancing downwards and the instability and failure on the top will be occurred during the first stage of underground mining. However, safety factor of the pit floor will be less influenced through the whole underground mining, with the slope remaining stable at all.