Lv Xiaobo, Hu Shengyong, Nian Jun, Deng Chunsheng, Zhao Bo, He Cheng, Wang Yansheng, Zhang Xitu, Zhang Wei
School of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan, China.
College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024, China.
Sci Rep. 2024 Nov 29;14(1):29743. doi: 10.1038/s41598-024-81256-7.
The behavior of gas migration in goaf under double roof cutting conditions directly influences the effectiveness of gas control measures. This study employs a combination of numerical simulation and field verification to investigate the patterns of gas migration and accumulation in goaf and to develop coordinated gas control methods under the conditions of double roof cutting and retained roadway. The results indicate that with double roof cutting, goaf permeability generally increases from the interior towards the exterior, with significantly higher porosity in the separation range compared to other areas. High permeability channels form along the sides of the open-off cut, the working face, and the two roadways, subsequently becoming areas of gas accumulation. High-level directional long borehole drainage achieves the best gas drainage at the bottom of the goaf on the working face and belt roadway sides, reducing gas concentration in the working face space to below 0.5%. Pipe jacking extraction along the retained roadway effectively reduces gas concentrations on the working face side and both roadway sides, maintaining working face gas concentrations consistently below 0.3%. Supplementary cutting hole drilling and extraction post-goaf formation show optimal gas extraction results on the working face side and near the two roadways, with gas concentration in the upper corner and return airflow remaining below 0.3% and trending downward. Field data validate the numerical simulation experiment theory.
双巷切顶条件下采空区瓦斯运移规律直接影响瓦斯治理措施的效果。本研究采用数值模拟与现场验证相结合的方法，研究采空区瓦斯运移与积聚规律，制定双巷切顶与留巷条件下的协同瓦斯治理方法。结果表明，双巷切顶后，采空区渗透率总体上由内向外增大，离层范围内孔隙率明显高于其他区域。采空区开切眼、工作面和两条巷道两侧形成高渗通道，随后成为瓦斯积聚区域。高位定向长钻孔抽采在工作面和胶带巷侧采空区底部瓦斯抽采效果最佳，将工作面空间瓦斯浓度降至0.5%以下。沿留巷进行顶管抽采可有效降低工作面侧和巷道两侧的瓦斯浓度，使工作面瓦斯浓度始终保持在0.3%以下。采空区形成后进行补切眼钻孔抽采，在工作面侧和两条巷道附近瓦斯抽采效果最佳，上角和回风巷瓦斯浓度保持在0.3%以下且呈下降趋势。现场数据验证了数值模拟实验理论。
