Triaxial hydraulic fracturing experiments were used to study the initiation pressure variation and acoustic emission characteristics of different guide seams sizes during roof hydraulic fracturing. Numerical simulations were used to explore the feasibility of multiple boreholes with prefabricated guide seams. An experiment of hydraulic fracturing on a pillar-free working face was also carried out in a coal mine. The results show that the specimens with guide seams reduced the initiation pressure, with the number of acoustic emission events and initiation pressure being inversely proportional to the size of the guide seams. Specimens without guide seams were deflected by stress and produced multi-level cracks, while the specimens with guide seams did not produce large secondary cracks and deflection. When the stress difference was small, three holes penetrated but not under large stress differences. The hydraulic fracturing technology of prefabricated longitudinal guide seams was tested in the Ningtiaota Coal Mine, and the auxiliary transportation roadway of S1201 working face was successfully retained for reuse in adjacent working faces.

采用三轴水力压裂实验研究顶板水力压裂过程中不同导缝尺寸的起裂压力变化和声发射特性。数值模拟用于探索具有预制导缝的多个钻孔的可行性。某煤矿也进行了无柱工作面水力压裂试验。结果表明，带有导缝的试件降低了起爆压力，声发射事件的数量和起爆压力与导缝的尺寸成反比。无导缝试件受应力偏斜，产生多级裂纹，带导缝试件未产生较大的二次裂纹和偏斜。当应力差较小时，三个孔被穿透但没有受到很大的应力差异。预制纵向导缝水力压裂技术在宁条塔煤矿进行试验，成功保留S1201工作面辅助运输巷道回用相邻工作面。