申南凹煤矿顶板采动裂隙发育数值模拟研究

Numerical Simulation of Mining-induced Fracture Development of Roof of Shennanwa Coal Mine

针对申南凹煤矿20102工作面开采中大量瓦斯从邻近层涌出至工作面,造成瓦斯超限,威胁矿井安全生产的问题,需采用高位钻孔抽采,钻孔目标层位直接决定高位卸压抽采效果。通过UDEC软件,采用摩尔-库伦模型建立模型,选取2号煤层及顶底板煤岩物理力学参数,并设置监测点。通过对岩层位移、应力、监测点位移以及岩层张开性裂隙及滑移变形分析,得出2号煤层开采后裂隙带最大发育高度为43m,且竖向裂隙发育区域呈开口向下的抛物线状,离层裂隙发育宽度约21m,竖向裂隙发育最大宽度约53m。结合矿井实际情况,建议高位钻孔终孔布置在距煤层顶板垂直方向20~35m,水平方向距回风巷煤壁15~30m。

In 20102 working face of Shennanwa Coal Mine,a large amount of gas gushing from the adjacent layer to the working face causes gas over-limit and threatens the safety production of the mine.It is necessary to adopt high level drilling and extraction,and the target layer of drilling directly determines the effect of high level decompression and extraction.Through UDEC software,Mohr-Coulomb model was used to establish the model.Physical and mechanical parameters of 2#coal seam,roof and floor coal and rock were selected and monitoring points were set.Based on the analysis of rock displacement,stress,monitoring point displacement,open fracture and slip deformation,it is concluded that after mining of 2#coal seam,the maximum development height of the fracture zone is 43 m,and the vertical fracture development area is a parabola with downward opening.The development width of the ionospheric fracture is about 21 m,and the maximum width of the vertical fracture is about 53 m.Combined with the actual situation of the mine,it is suggested that the final hole of the high borehole is arranged from 20 m to35 m perpendicular to the roof of the coal seam,and 15 m to 30 m from the wall of the coal shaft in the horizontal direction.