Niu Zhijun, Wang Xufeng, Wang Cong, Feng Zhiwei, Shen Chengyang
School of Mines, Jiangsu Engineering Laboratory of Mine Earthquake Monitoring and Prevention, China University of Mining and Technology, Xuzhou, 221116, China.
Huaxia Tianxin Internet of Things Technology Co., Ltd. Xuzhou Branch, Xuzhou, 220006, China.
Sci Rep. 2025 Jan 6;15(1):968. doi: 10.1038/s41598-024-83842-1.
Aiming at the problems of complex stress and large deformations in the surrounding rocks of the roadway driven under the goafs of small collieries and heading for adjacent advancing coal face, by numerical modeling and field practice, the failure characteristics of the overlying coal and rocks were investigated, and the stopping and resuming times of the roadway excavation were identified. A zoning-based reinforcement technique was put forward and applied in engineering practice. The results showed that (1) The roadway roof was divided into four zones: "Rolid coal zone", "Residual pillar zone", "Roof caved zone", and "Roof un-caved zone". (2) It was determined that the roadway excavation was stopped when the unmined distance between the return airway face and the 32,101 working face was 70 m. After the 32,101 working face passed the return airway face by 90 m, the roadway driving was restarted. (3) I.e. cable reinforcement for the "residual pillar zone" and bolt-wire mesh-cable-shotcreting-grouting reinforcement for the "roof failure zone" ("Roof caved zone" + "Roof un-caved zone"). The field observation results indicated that the maximum amount of the roof-to-floor convergence and the wall-to-wall convergence was 97 mm and 69 mm, respectively, which ensured the safety of roadway excavating.
针对小煤矿采空区下方巷道掘进且临近回采工作面时围岩应力复杂、变形大的问题，通过数值模拟和现场实践，研究了上覆煤岩的破坏特征，确定了巷道掘进的停掘和复掘时间。提出了基于分区的加固技术并应用于工程实践。结果表明：（1）巷道顶板分为“实体煤区”“残余煤柱区”“顶板垮落区”和“顶板未垮落区”四个区域。（2）确定当回风巷工作面与32101工作面的未采动距离为70 m时停止巷道掘进。32101工作面过回风巷工作面90 m后，重新开始巷道掘进。（3）即对“残余煤柱区”采用锚索加固，对“顶板破坏区”（“顶板垮落区”+“顶板未垮落区”）采用锚杆-金属网-锚索-喷射混凝土-注浆加固。现场观测结果表明，巷道顶底板最大收敛量和两帮最大收敛量分别为97 mm和69 mm，确保了巷道掘进的安全。
