梁北矿高瓦斯特软煤层巷道变形特征及原因

Characteristics and reason of deformation of the roadway in the special soft coal with high gas content in the Liangbei Coal Mine

梁北矿-550m水平二1煤层属典型“三软”煤层,煤层透气性差,瓦斯含量高、压力大,地应力大,具有较强的突出危险性.11采区煤巷埋深达610 ～ 750m,现场调查表明,巷道持续大变形,底鼓严重,支护难度大.本文对梁北矿-550m水平11采区二1煤层巷道工程地质特征进行了调研,总结了煤巷变形特征,运用FLAC数值模拟方法对巷道大变形的原因进行了分析.指出该煤巷变形以显著底鼓为特征,其主要原因是煤层软弱、底板煤扰动、瓦斯防突钻孔效应和支护缺陷.认为高瓦斯特软煤层巷道的支护应兼顾瓦斯治理与支护两方面,宜把它们当成一个系统进行协同分析,这是有效解决此类煤巷稳定性控制难题的一种有效途径.在此基础上,提出了相应的防治对策.

The B1 coal seam at -550 m level in the Liangbei Coal Mine is a typical ＂three-soft＂ coal seam. There are relatively strong gas outbursts due to soft coal and poor air permeability, high gas content and high gas pressure in the coal. The coal roadway at the 11 mining area has a depth of 610 to 750 m. The in-situ investigation indicates that there are problems of large deformation, serious floor heave in the coal roadway. The engineering geological characteristics of the rock surrounding roadway in the B1 coal seam at -550 m level is examined, and the deformation characteristics is summarized. The reason of large deformation is also analyzed by using the FLAC numerical test method. The results show that the coal roadway deformation is characterized by the serious floor heave, and the main reasons are weak floor coal, floor disturbance, effect of boreholes for gas outburst prevent and the support defects. Both the roadway support and gas treatment should be synergistically considered as the same system for the coal roadway within soft coal with high gas content. It is an effective way to control the larger deformation of the roadway. The corresponding control countermeasure is also put forward.