孤岛综放面回采巷道围岩稳定性控制研究

Research on Surrounding Rock Stability Control of Mining Roadways in Island Fully Mechanized Caving Face

为有效解决孤岛工作面巷道变形量大、围岩稳定性控制难题,以高河煤矿E2306孤岛面为工程背景,采用理论分析、数值模拟及现场实测相结合的研究方法,对孤岛面区段煤柱的合理尺寸及巷道支护方式进行研究。结果表明:基于应力极限平衡理论和内应力场分布规律构建了区段煤柱边缘体力学计算模型,提出了E2306孤岛面区段宽煤柱护巷方法,对比分析不同煤柱宽度掘巷、回采阶段围岩应力、位移及塑性区演化特征,明晰了区段煤柱的尺寸效应,确定了最佳区段煤柱宽度为30 m;采用“锚网索+钢筋梯子梁”的联合支护方式,经现场应用围岩控制成效显著,有效减小了沿空巷道围岩变形量,提高了沿空巷道围岩稳定性。研究成果实现高河煤矿煤炭资源安全增产123.4万t,同时可为其他同类工程难题提供参考和技术指导。

In order to effectively solve the problems of large deformation of the roadway of the working face of the isolated island and the stability control of the surrounding rock,the reasonable size of the coal pillar in the isolated area section and the support method of the roadway support method of the isolated island section were studied by taking the E2306 isolated island surface of Gaohe coal mine as the engineering background,and the research method of combining theoretical analysis,numerical simulation and on-site measurement was adopted.The results show that based on the stress limit balance theory and the distribution law of the internal stress field,a calculation model of the edge of the coal pillar in the section is constructed,and the E2306 isolated island surface section wide coal pillar guarding method is proposed,and the evolution characteristics of the surrounding rock stress,displacement and plastic zone of different coal pillar width excavation and recovery stage are compared and analyzed,the size effect of the section coal pillar is clarified,and the optimal section coal pillar width is 30 m;the joint support method of"anchor net cable+reinforced ladder beam"is used,and the surrounding rock control is effectively applied on the spot.It effectively reduces the deformation of the surrounding rock along the empty roadway and improves the stability of the surrounding rock along the empty roadway.The research results have achieved a safe increase in coal resources in Gaohe coal mine by 1.234 million tones,and can provide reference and technical guidance for other similar engineering problems.