临近采空区切眼留巷围岩稳定控制技术

Surrounding rock stability control technology of open-cutting entry retaining near goaf

针对临近采空区切眼实施留巷围岩控制难题,通过理论分析及现场试验,对切眼留巷支护系统及卸压关键技术开展研究。提出了顶板卸压、围岩主动支护、高强度被动加固的综合围岩控制技术方案与工艺流程。针对厚层坚硬顶板实施“定向预裂+松动爆破”组合卸压技术,通过参数优化设计,实现了90%的单裂缝面及架后采空区顶板及时冒落,改善了围岩结构;采后及时采用“帮部加强锚索+顶板恒阻锚索+挡矸密闭+交替木垛+单体棚”支护,通过主被动支护加固措施控制围岩变形。工作面推进280m时切眼留巷围岩稳定,两帮移近量小于300mm,以底鼓为主的顶底板移近量小于500mm,切眼留巷围岩控制效果满足生产需求。

In order to solve the problem of surrounding rock control of open-cutting entry retaining near goaf, the supporting system and key technologies of pressure relief were studied through theoretical analysis and field test. The comprehensive surrounding rock control technology system and process of roof pressure relief, surrounding rock active support and high strength passive reinforcement were proposed. The “directional pre-splitting+loose blasting” combined pressure relief technology was implemented for thick hard roof. Through parameter optimization design, 90% of the single fracture surface and the roof of the goaf behind the hydraulic supports was timely caving, and the surrounding rock structure was improved. After mining, the support of “reinforcement anchor cable for coal side + constant resistance anchor cable for roof+gangue sealing support+alternating wooden stack+hydraulic single shed” was adopted in time, and the deformation of surrounding rock was controlled by active and passive support reinforcement measures. When the working face was mined at 280 m, the surrounding rock of the open-cutting retaining roadway was stable, the displacement of the two sides was within 300 mm, and the displacement of the roof and floor based on the floor heave was less than 500 mm. The surrounding rock control effect met the production demand.