煤巷围岩松动变形对边掘边抽的影响分析

随着煤巷掘进工作面的向前推进,破坏了原始煤体的稳定性,煤层巷道两侧的煤壁在一定范围内形成一个松动变形圈,在此变形圈内煤岩体将向巷道空间移动。根据数值模拟计算和现场观察与测试,发现随着巷道沿煤层向前掘进,掘进头以及巷道两帮煤体的应力变化影响圈或松动变形特征呈“U”字形状。在“U”字形松动变形范围内,煤层透气性系数增加数十倍。现场考察了松软厚煤层巷道周围煤岩体位移及松动变形对边掘进巷道边抽放瓦斯效果和影响抽放瓦斯效果的因素,对边掘边抽布置方式和封孔工艺的改进具有一定的指导意义。

On Properties of Loose and Deformation of the Coal around Roadway Dug in Loose-soft and Thick Coal Seam

Excavating the laneway along the coal bed can destroy the stability of the initial coal. The coal around the laneway forms a loose deformed loop and the coal in this deformed loop will shift to the space of the laneway. Based on the numerical modeling in the laboratory and spot observation and testing, the loop of the variation of the stresses in tunneling end and the both sides of the laneway appears "U" shape. The coefficient of gas permeability increases by several hundred folds in the range of this "U" deformed loop. The displacements of coal and the characteristics of loose deformation around the laneway can provide basic parameter for the prevention and cure of gas outburst during the tunneling of coal laneway, the gas extracting project and the supporting of the coal laneway.