孤岛工作面围岩支承压力分析与沿空掘巷支护参数优化

Analysis of supporting pressure of surrounding rock in island mining face and optimization of supporting parameters of gob-side entry driving

为研究孤岛工作面围岩支承压力特征与沿空掘巷支护参数优化,建立了三维数值模型,制定了相应的试验方案,研究了孤岛工作面沿空掘巷支护参数变化和围岩控制效果之间的相互关系,支护系统整体的协调性,并确定了最优支护方案。研究结果显示:随着锚杆长度增加,形成的组合梁厚度加大,孤岛工作面沿空掘巷的顶板岩层内的压应力增加,拉应力降低,减小锚杆的间排对于巷道有明显的支护效果,但锚杆长度和间排距均存在最优值;锚索长度对孤岛工作面沿空掘巷顶板内的压应力没有作用,而巷道两帮围岩水平方向的拉应力升高;支护系统最大应力随着锚索间排距的增加,而支护系统的单根锚索应力降低。现场实测验证了围岩控制效果。

Because of the increase of lateral stress concentration on the Island mining face,the pressure is difficult to control.In order to study the characteristics of abutment pressure of gob-side entry driving surrounding rock of island mining face and supporting parameters optimized.A three-dimensional numerical model is established,and formulate the corresponding testing scheme,study the supporting parameters of gob-side entry driving isolated working face changes and the relationship between the control effect of surrounding rock,the supporting system of the whole coordination,and determine the optimal supporting scheme.The results show that:with the increase of bolt length,the thickness of the formed composite beam increases,the compressive stress increases and the tensile stress decreases in the roof rock layer of the gob-side entry driving in the island mining face.The length of anchor cable has no effect on the compressive stress in the roof of the roadway along the working face of the isolated island,while the horizontal tensile stress of the surrounding rock on both sides of the roadway increases.The maximum stress of a single anchor cable decreases with the increase of row spacing between anchor cables.The field measurement verifies the effect of surrounding rock control and provides a certain reference for similar projects.