基于极限分析法和数值模拟的条采岩层稳定性分析

Stability analysis of strip rock stratum based on limit analysis method and numerical simulation

为解决红阳二矿西三下部采区村下压煤问题,保证村下采区稳定安全,实现矿区可持续开采,以该采区压煤开采地质条件和煤层赋存情况为研究基础,应用轴向力作用下岩层稳定性极限平衡分析法进行理论分析,结合采煤沉陷预计软件对地表移动变形进行预计,利用数值模拟对理论分析和沉陷预计的结果进行合理性验证,综合以上研究过程得到如下结论:(1)村下压煤条采,沿采空区倾向,顶板位移从两边到中间呈增大趋势,且在采区中间位置达到最大位移值979.3 mm;(2)从采空区顶板至地表,沿采区垂向,岩层位移值呈减小趋势,在地表处达到最小位移值3.45 mm;(3)在采深760 m时,村下采空区上覆岩层应力分布重新达到平衡,可保持稳定大约10年,采深达到815 m时,采空区及上覆岩层逐渐趋于稳定并维持大约5.6年;(4)采煤沉陷预计地表最大沉降值W=720 mm;最大曲率值K=0.005×10^(-3)/m;最大水平变形值ε=0.45 mm/m;(5)数值模拟分析结果与极限分析法、采煤沉陷预计结果一致,可为村下压煤开采提供稳定性判据,避免了采区采动损害引发地表塌陷灾害。

In order to solve the pressed coal problem of Hongyang second mine under the village, guarantee the stability and safety of mining area, and achieve coal area sustainable mining, the following study is based on the geological conditions of the mining area and the occurrence of coal seam, the limit analysis method is used to analyze the theory, combined with the prediction of the surface movement and deformation by using the prediction software . Also, the numerical simulation is used to verify the rationality of the results of theoretical analysis and subsidence prediction. Based on the above research process, the following conclusions is got ： （ 1 ） The displacement of the roof is increasing from both sides to the middle along the gob tendencies, and the maximum displacement value is 979.3 mm in the middle of the mining area. （2） From the top roof of the gob to the surface, along the area vertical, the displacement value of the rock is decreasing, and the minimum displacement is 3.45 mm at the surface. （3） At the depth of 760 m, the stress distribution of overlying strata of the gob below the village is to achieve a balance again and maintain the stable for about 10 years. When the mining depth is 815 m, the gob and overlying strata are gradually stabilized and maintain for about 5.6 years. （4） By coal mining subsidence predicting, the maximum sedimentation value of the surface is W = 720 mm,the maximum curvature value is K = 0. 005 × 10^ -3/m, and the maximum horizontal deformation value is e = 0.45 mm/m. （5） The results of numerical simulation analysis are consistent with the limit analysis method and the results of coal mining subsidence prediction, which can provide the theoretical basis for the mining of pressed coal under