近距离残留煤柱下破碎围岩巷道修复技术

Roadway repair technology of broken surrounding rock under residual coal pillar for close distance coal seams

针对近距离煤层开采过程中,残留煤柱下部巷道在煤柱集中应力作用下围岩破碎程度高、修复难度大的问题,以山西某矿为工程背景,采用数值模拟的方法分析煤柱底板应力分布规律,结合巷道实际变形特征总结了下位巷道围岩变形破坏原因。认为:残留煤柱底板集中载荷的非均匀性分布,及其引起的支护体承载结构破坏是近距离煤柱底板巷道围岩发生大变形的本质。由此,提出了基于破碎围岩注浆和高强度锚杆支护的巷道修复技术,工程实践表明该技术在有效提高围岩整体性和可锚性的同时,使浅部锚固区与深部围岩相连形成整体承载结构,有效地控制了巷道围岩变形,保障了矿井安全生产。

Aiming at the problems that underlying surrounding rock of roadway of residual coal pillar was crushed seriously and repaired difficultly,which influenced by the concentrated stress of coal pillar in the process of close distance coal seam mining,basing on the engineering background of a mine in Shanxi province,the stress distribution law of coal pillar floor was analyzed by numerical simulation method and the causes of deformation and failure of surrounding rock were summarized which based on the actual deformation characteristics of roadway.It was found that the concentrated load in the floor of residual coal pillar distributed homogeneously,leading to the destruction of support bearing structure which was the root cause of large deformation of surrounding rock of roadway under coal pillar in close distance coal seams.Therefore,the roadway repair technology composing of grouting reinforced and high strength bolt support for broken surrounding rocks was proposed.The project practice showed that the integrity and anchoring ability of roadway surrounding rocks was improved significantly and the anchorage zones and deep surrounding rocks were connected,so that the deformation of roadway surrounding rock was effectively controlled,and safety production of mine was guaranteed.