Li Yingfu, Chang Guanfeng, Hu Di, Song Wu
School of Mining Engineering, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
State Key Laboratory for Safe Mining of Deep Coal Resources and Environment Protection, Huainan, 232000, China.
Sci Rep. 2025 Jul 15;15(1):25458. doi: 10.1038/s41598-025-10964-5.
The 360,606 working face of Xinji 1 Mine was taken as an engineering case to address the significant safety hazards associated with coal mining under hard roof. A key technical scheme for pre-splitting blasting roof-cutting pressure relief was developed by theoretical analysis, numerical simulation, and field experiments. The results are as follows. (1) Fracture propagation was dominated by synergistic effects of explosion gases and stress waves. Explosive energy was concentrated at crack tips after exploration. When accumulated energy exceeded the rock's deformation capacity, cracks propagated further. (2) Explosive energy distribution was optimal between the crushing zone and fracture zone at a decoupling coefficient of 1.5, which avoided energy waste from over-fragmentation. A 5-m spacing yielded a peak effective stress of 98.6 MPa at the midpoint between boreholes. Integrated stress cloud analysis indicated that a spacing of 5 m was optimal. (3) Post-implementation displacements were measured as follows: roof (238 mm), coal pillar sidewall (124 mm), mining sidewall (100 mm), and floor (48 mm). The successful retention of the 306,606 working face gateway validated the efficacy of this technology in roof-cutting and roadway protection. These findings provide technical guidance for coal extraction under analogous engineering.
以新集一矿360606工作面为工程案例，解决坚硬顶板下采煤存在的重大安全隐患。通过理论分析、数值模拟和现场试验，制定了预裂爆破切顶卸压关键技术方案。结果如下：（1）裂隙扩展以爆炸气体和应力波的协同作用为主导。爆炸能量在探孔后集中于裂纹尖端。当累积能量超过岩石的变形能力时，裂纹进一步扩展。（2）在不耦合系数为1.5时，爆炸能量在破碎区和裂隙区之间的分布最佳，避免了过度破碎造成的能量浪费。间距为5 m时，钻孔中点处的峰值有效应力为98.6 MPa。综合应力云图分析表明，5 m的间距是最佳的。（3）实施后的位移测量结果如下：顶板（238 mm）、煤柱侧壁（124 mm）、采空区侧壁（100 mm）和底板（48 mm）。306606工作面巷道的成功保留验证了该技术在切顶和巷道保护方面的有效性。这些研究结果为类似工程条件下的煤炭开采提供了技术指导。
