工作面上方厚坚硬顶板水力弱化技术实践

Hydraulic weakening technology practice of thick and hard roof above working face

为使韩家湾煤矿213108工作面在初采初放过程中上部坚硬基本顶及时垮落,杜绝采空区大面积悬顶,降低来压强度,确保工作面初采初放安全回采。通过分析水力压裂技术原理及施工工艺,对水力卸压钻孔进行设计,采用高、中、低位3种钻孔的联合布置形式,保证弱化效果和顶板垮落时间。在厚坚硬顶板水力弱化后对巷道的围岩变形量和端头悬顶长度进行了监测分析。结果表明,水力弱化顶板后,213108工作面回采期间围岩变形量较小,巷道端头悬顶长度在合理范围内,未出现大面积悬顶现象。

In order to make the upper hard basic roof of 213108 working face of Hanjiawan Coal Mine collapse in time during the initial mining and initial caving, put an end to large-area suspended roof in the goaf, reduce the weighting strength, and ensure the safe mining of the working face during the initial mining and initial caving.Through the analysis of hydraulic fracturing technology principle and construction technology, hydraulic pressure relief drilling is designed, and the joint arrangement of high, medium and low drilling is adopted to ensure the weakening effect and roof collapse time.After the hydraulic weakening of thick and hard roof slab, the deformation of surrounding rock and the length of suspended roof at the end of the roadway are monitored and analyzed.The results show that after the roof is weakened by water power, the deformation of surrounding rock in 213108 working face is small during the mining period, and the length of roadway end hanging roof is within a reasonable range, without large area hanging roof phenomenon.