Chi Mingbo, Tang Haibo, Liu Dapeng, Wang Dongdong, Dai Chuangchuang, Zou Junpeng, Gao Quanwu, Feng Gan
China Academy of Safety Science and Technology, Beijing, 100011, PR China.
Institute of Mining and Engineering, Taiyuan University of Technology, Taiyuan, 030024, PR China.
Heliyon. 2024 May 3;10(10):e30679. doi: 10.1016/j.heliyon.2024.e30679. eCollection 2024 May 30.
This study explores the causes of coal bursts in the Xinzhou Kiln Mine, identifying key factors such as residual pillars, hard coal seams and/or roofs, stress concentration due to complex geological structures, and the stress distribution characteristics of the primary rock. A significant finding is that hydraulic cutting not only diminishes and redistributes the stress concentration region inside the coal seam but also mitigates the burst potential of the coal-rock mass, fundamentally reducing the likelihood of coal bursts. By taking Face No. 8937 in Xinzhou Kiln Mine as the test object, a coal burst prevention test was performed using hydraulic cutting. In combination with theoretical analysis and numerical simulation, the mechanism of hydraulic cutting for preventing coal burst was discussed, and reasonable cutting parameters were established. Onsite monitoring revealed that hydraulic cutting disrupts the integrity of the coal-rock mass, releases internal stress, and increases its water content, thereby weakening its burst tendency. Additionally, the deformation and fracturing of the cutting slots and the closure of boreholes shifted the stress concentration from the coal seam to deeper areas and to the two ribs. Post-cutting observations showed a significant reduction in both the frequency and impact energy of coal bursts; there was also a noticeable increase in the convergence of the roadway in the cutting area compared to non-cutting areas. Furthermore, displacement of the roof and floor increased by 78.9 % and that of the two ribs increased by 47.4 % after cutting, preventing the coal-rock mass from accumulating high stress. In conclusion, hydraulic cutting is a promising method for effectively preventing coal bursts and enhancing the safety of mining operations.
本研究探讨了忻州窑矿煤与瓦斯突出的成因，确定了诸如残留煤柱、硬煤层和/或顶板、复杂地质构造导致的应力集中以及原岩应力分布特征等关键因素。一个重要发现是，水力割缝不仅能减小并重新分布煤层内部的应力集中区域，还能降低煤岩体的突出潜能，从根本上降低煤与瓦斯突出的可能性。以忻州窑矿8937工作面为试验对象，进行了水力割缝防突试验。结合理论分析和数值模拟，探讨了水力割缝防突机理，并确定了合理的割缝参数。现场监测表明，水力割缝破坏了煤岩体的完整性，释放了内部应力，增加了其含水量，从而减弱了其突出倾向。此外，割缝的变形和破裂以及钻孔的闭合将应力集中从煤层转移到更深区域和两帮。割缝后观测表明，煤与瓦斯突出的频率和冲击能量均显著降低；与未割缝区域相比，割缝区域巷道的收敛也明显增加。此外，割缝后顶底板位移增加了78.9%，两帮位移增加了47.4%，防止了煤岩体积聚高应力。总之，水力割缝是一种有效防止煤与瓦斯突出、提高开采作业安全性的有前景的方法。
