基于数值模拟的郭家滩煤矿充填开采最佳充填率分析

Analysis of optimum filling rate for filling mining in Guojiatan Coal Mine based on numerical simulation

为缓和水资源保护与高强度的煤炭开采之间的矛盾,以郭家滩煤矿20102工作面为研究背景,采用以数值模拟为主的研究手段,阐述了固体充填开采控制覆岩运移的基本机理,分析了不同充填率条件下覆岩导水裂隙带高度发育规律和覆岩移动变形特征,最终给定了含水层下固体充填开采合理充填率。结果表明,随着充填率的增加,上覆岩层移动强度减弱,导水裂隙带发育高度不断减小,覆岩变形大幅度降低,地表下沉量与基本顶下沉量的比值逐渐降低。当充填率为0%、20%、40%、60%、80%时,导水裂隙带高度分别为125.6 m、102.3 m、76.5 m、48.6 m、22.5 m;表土层最大水平变形分别为5.19 mm/m、4.06 mm/m、2.81 mm/m、1.72 mm/m、0.92 mm/m。导水裂隙带不贯通至直罗组含水层的合理充填率为60%以上,地表土层不发生破坏的合理充填率为60%以上,最终确定20102工作面的合理充填率为60%。

In order to alleviate the contradiction between water resources protection and high-intensity coal mining,taking the 20102 working face of Guojiatan Coal Mine as the research background and using numerical simulation as the main research method,we expound the basic mechanism of controlling overlying strata movement by solid filling mining,analyze the height development law of overlying strata water-conducting fracture zone and the characteristics of overlying strata movement and deformation under different filling rates,and give the reasonable filling rate of solid filling mining under aquifer.The results show that with the increase of filling rate,the movement intensity of overlying strata weakens,the development height of water-conducting fracture zone decreases,the deformation of overlying strata decreases greatly,and the ratio of surface subsidence to basic roof subsidence decreases gradually.When the filling rate is 0%,20%,40%,60%and 80%,the height of water-conducting fracture zone is 125.6 m,102.3 m,76.5 m,48.6 m and 22.5 m,respectively.The maximum horizontal deformation of topsoil is 5.19 mm/m,4.06mm/m,2.81 mm/m,1.72 mm/m and 0.92 mm/m,respectively.The reasonable filling rate of the water-conducting fracture zone that does not run through to the aquifer of Zhiluo Formation is above 60%,and the reasonable filling rate of the surface soil layer without failure is above 60%.Finally,the reasonable filling rate of the 20102 working face is determined to be 60%.