Shaanxi Huangling No. 2 Coal Mine Co., Ltd.

针对厚煤层综采工作面留设煤柱沿空掘巷巷道围岩大变形技术难题,以陕西黄陵二号煤矿422工作面回风巷为工程背景,分析切顶卸压围岩稳定控制机理,认为切顶卸压节理为切断应力传递路径、减小悬顶长度、改善应力集中,理论确定了切顶高度及角度等技术参数。结合422工作面生产条件,确定了422回风巷煤柱侧水压致裂切顶卸压技术方案并应用于现场实践。现场监测结果表明,422回风巷采用切顶卸压技术后,两帮收敛量最大为148mm,顶底板移近量最大为174mm,有效降低了巷道围岩应力,保证工作面安全高效回采。

In view of the technical problem of large deformation of surrounding rock of roadway driving along goaf with coalpillar reserved in fully mechanized mining face of thick coal seam, we take the return air roadway of 422 working face ofHuangling No. 2 Coal Mine in Shaanxi Province as an engineering background, analyze the stability control mechanism ofroof cutting pressure relief surrounding rock, and theoretically determine the roof cutting height and angle and other technicalparameters. The technical scheme of the hydraulic fracturing roof cutting of the coal pillar side in the 422 return air roadwayis determined and applied to the field practice. The field monitoring results show that the maximum convergence of the twosides is 148 mm and the maximum displacement of the roof and floor is 174 mm after the 422 return air roadway adoptingthe roof cutting pressure relief technology, which effectively reduces the stress of the surrounding rock of the roadway andensures the safe and efficient mining of the working face.