Chen Dingchao, Wang Xiangyu, Bai Jianbiao, Zhao Jiaxin, Zhou Qingcong, Ji Xiang
School of Mines, China University of Mining and Technology, Xuzhou, 221116, China.
State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Xuzhou, 221116, China.
Heliyon. 2024 Oct 3;10(19):e38933. doi: 10.1016/j.heliyon.2024.e38933. eCollection 2024 Oct 15.
Gob-side entry retaining (GER) play a crucial role in enhancing coal recovery, improving roadway stress conditions, and ensuring safe and efficient mining operations. This study focuses on investigating the stability characteristics of surrounding rock using flexible formwork concrete (FFC) along the headgate of 3405 panel. According to the fracture pattern of roof, a mechanical model of GER was developed. This study derived expressions for the support resistance of the filling body and determined its optimal bearing capacity. A FLAC numerical model was employed to simulate the GER process, segmented into early, middle, and late stages. Simulation results demonstrate a progression in peak deviatoric stress and extent of plastic zones in the surrounding rock. This evolution includes an initial minor increase (early stage), followed by rapid escalation (middle stage), and eventual stabilization (late stage). The middle stage emerges as critical, characterized by pronounced mining-induced stress effects on the roof. During this phase, significant changes are observed in deviatoric stress curves, with plastic zones rapidly migrating deeper into the rock mass. Practical implementation of the findings revealed a maximum deformation of the filling body of only 198 mm, affirming the feasibility of employing FFC in GER. This research provides valuable insights into managing stability concerns in GER thereby enhancing safety and operational efficiency in coal mining under similar conditions.
沿空留巷在提高煤炭回收率、改善巷道应力条件以及确保安全高效的采矿作业方面发挥着关键作用。本研究着重于利用柔性模板混凝土（FFC）对3405采区运输巷沿空留巷围岩的稳定性特征进行研究。根据顶板的断裂模式，建立了沿空留巷的力学模型。本研究推导了充填体支护阻力的表达式，并确定了其最佳承载能力。采用FLAC数值模型对沿空留巷过程进行模拟，该过程分为早期、中期和后期。模拟结果表明，围岩中偏应力峰值和塑性区范围呈递进变化。这种演变包括初期的小幅增加（早期），随后迅速上升（中期），最终趋于稳定（后期）。中期是关键阶段，其特征是采动应力对顶板产生显著影响。在此阶段，偏应力曲线出现显著变化，塑性区迅速向岩体深部迁移。研究结果的实际应用表明，充填体的最大变形仅为198毫米，证实了在沿空留巷中采用柔性模板混凝土的可行性。本研究为解决沿空留巷中的稳定性问题提供了有价值的见解，从而提高了类似条件下煤矿开采的安全性和作业效率。
