摘要
为提高煤层小断层附近瓦斯突出防治的针对性,以古汉山矿地质条件为背景,通过数值模拟研究了与工作面开采方向0°夹角、45°夹角、90°夹角小断层附近采动应力演化特征。结果表明,当工作面沿地应力场最大主应力方向开采时,小断层附近构造应力逐渐得到释放,与工作面0°夹角断层和与工作面45°夹角断层附近的采动应力场分布均匀,工作面瓦斯突出的危险性小,而与工作面90°夹角断层因断层应力阻隔效应,工作面的采动应力分布呈现差异,瓦斯突出危险部位沿断层走向分布;当沿工作面垂直最大主应力方向开采时,断层附近的构造应力叠加与断层应力阻隔效应一起导致采动应力逐渐增大,工作面采动应力分布呈现显著差异,在小断层附近存在瓦斯突出危险部位。煤矿现场瓦斯突出防治应在加强小断层探测的基础上,结合区域地应力场方向、开采条件、断层走向,对断层附近瓦斯突出危险部位做出预测,从而提高小断层附近瓦斯突出防治工作的针对性。
The present paper takes it as its goal to present an anaylysis of the evolutionary characteristics of the mining-induced stress near the small-scale faults areas of the coal seam. As is well known,it is often the case that coal and gas outbursts take place in the coal-abundant band and great tectonic stress near the small-scale faults in the coal seam,thus seriously threatening the coal mining safety. To prevent and avoid such gas outburst hazards effectively,we have done investigations over the mining-induced stress evolution process of the faults while the working face is advancing by using three Mohr-Coulomb models in angles of0°,45°,90° to the working face correspondingly with a software named as FLAC3 D. The results of our investigation show that the tectonic stress near the small-scale faults tends to get released gradually when the maximum in-situ stress is aligned parallel to the working face. This is because the mining-induced stress tends to be homogeneous near the angle from 0° and 45° to the smallscale fault,but a high stress concentration,high stresses and high displacement gradients would like to appear ahead of the working face along the strike of 90° fault due to the stress barrier,so that the outbursts are most likely to happen when the working face is advancing in the above said direction. Actually,the mininginduced stress tends to increase due to the stress barrier by the superposition trend of the tectonic stress near the faults when the maximum in-situ stress is aligned perpendicular to the working face axis.Therefore,great attention has to be paid to the different mining-induced stresses near the 0° small-scale fault,45° small-scale fault and that of the 90° one,for they are areas prone to coal and gas outbursts. What is more,the abnormal stress area near the faults may also involve the complication of the in-situ stress field direction,the mining conditions and the faults strike,or the likely faults caused by the unqualified geoseismic detection. It is just for the aforementioned r
出处
《安全与环境学报》
CAS
CSCD
北大核心
2017年第6期2164-2170,共7页
Journal of Safety and Environment
关键词
安全工程
煤层小断层
构造应力
采动应力演化特征
safety engineering
small-scale faults in coal seam
tectonic stress
evolution characteristics of mining- induced stress
