不同倾角正断层附近应力分布规律数值模拟研究

Numerical Simulation Study on Law of Stress Distribution Near Normal Fault in Different Dip

查明不同倾角正断层附近应力分布规律对瓦斯分布规律预测、煤与瓦斯突出预测具有重要的参考价值。以鹤壁四矿31052采煤工作面内不同倾角正断层参数为基础,结合实验室岩石力学测试,构建了正断层地质模型;借助ANSYS有限元模拟软件对不同倾角(30、45、60°)正断层附近的应力分布进行模拟。结果表明:煤厚7.5 m、断层垂向高度50 m、断层倾角45°时,断层端部的应力集中程度最高,断层附近煤岩体破碎严重;工作面前方距断层40 m左右范围应力"释放区、集中区、正常区"三区界限较明显。断层长度、煤厚取值不同时,断层端部应力集中程度会发生变化。煤厚和工作面距断层距离对断层附近横向上应力变化有重要影响,断层垂向高度和断层倾角对断层附近纵向上应力变化有重要影响。

To find out stress distribution law near normal fault in different dip has more important reference value for gas distribution rule,coal and gas outburst prediction. Based on normal faults parameters of different angle within Hebi four mine 31052 coal mining face,combined with rock mechanics testing of laboratory, building a normal fault geological model;Meanwhile with the help of ANSYS finite-element simulation software, simulated stress distribution near the normal fault for different angle（30, 45, 60°）. The results showed that： If coal thickness was 7.5 m, fault vertical height was 50 m, and the fault angle was 45° of stress concentration of the fault ends was the ahighest and broken degree of coal and rock was serious near the fault; In the front of coal face 40 m away from the fault, ＂the release area, concentration area, normal area＂ three zone boundaries was more obvious.When the values of the fault length and coal thickness are different,the degree of the stress concentration near fault ends will change. Coal thickness and distance of face away from fault are the major controlling factors of determining the lateral stress variations near the fault. Fault vertical height and dips are the major controlling factors of determining the longitudinal stress variations near the fault.