Coalbed methane (CBM), which is extremely rich in deep coal reserves in China, is not only the material cause of gas explosion and coal-gas outburst disasters but also a clean and environmentally friendly energy source. Gas drainage must be carried out during deep coal mining to avoid gas accidents while obtaining clean energy. The low-level roadway is an effective gas drainage measure for coal seams with high coal-gas outburst risk and low-permeability, and it can simultaneously realize the functions of gas drainage before and during mining. Roadway tunneling has a strong influence on the stress and permeability properties of the adjusted coal seams, and further determines the gas drainage efficiency and the layout of the air-return roadway. Taking the Pingshu Coal Mine as an example, this paper analyzes the influence of the vertical distance between the low-level roadway and the underlying coal seam, and the influence of the width and height of the low-level roadway on the stress relief and deformation characteristics. The results indicate that the low-level roadway tunneling results in a nonuniform stress disturbance of coal seam #15. And a reasonable layout and size parameters of the air-return roadway in coal seam #15 were proposed based on which gas drainage practices were carried out with good effects in panel #15211. The research can effectively guide the elimination of coal and gas outburst in return air roadway, and achieve the purpose of safe and rapid tunneling coal roadway under the environment of highly-gassy coal seam. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.

中文翻译：

---

低位巷道掘进对下伏煤层瓦斯抽采的影响：数值分析及现场应用

煤层气（CBM）是我国煤炭储量极为丰富的深部，不仅是瓦斯爆炸和煤-瓦斯突出灾害的物质诱因，也是一种清洁、环保的能源。深部采煤必须进行瓦斯抽采，避免瓦斯事故，同时获得清洁能源。低位巷道是瓦斯突出风险高、渗透率低的煤层有效的瓦斯抽采措施，可同时实现采前和采中瓦斯抽采功能。巷道掘进对调整后煤层的应力和渗透特性影响很大，进一步决定了瓦斯抽采效率和回风巷道的布置。以平蜀煤矿为例，分析了低层巷道与下伏煤层垂直距离的影响，以及低层巷道宽度和高度对应力释放和变形特性的影响。结果表明，低层巷道掘进导致#15煤层的非均匀应力扰动。并在#15211面板进行瓦斯抽采实践的基础上，提出了合理的#15煤层回风巷布置和尺寸参数。该研究可有效指导回风巷煤与瓦斯突出的消除，达到高瓦斯煤层环境下煤巷安全快速掘进的目的。© 2021 化学工业协会和 John Wiley & Sons, Ltd.