采动诱发大采高工作面断层活化失稳机理及预测模型

Mechanism and Prediction Model of Fault Activation and Instability Induced by Mining in Working Face with Large Cutting Height

摘要: 针对大采高工作面开采过逆断层过程中断层活化诱发煤岩冲击失稳灾害问题，采用数值模拟软件FLAC^3D构建数值模型，对比分析了不同采高条件下采动作用对断层活化的影响，探讨了断层活化失稳过程中的应力场及位移场变化规律，基于加卸载响应比理论对模拟结果进行了分析，探讨了断层失稳的判定准则。研究结果表明：随着采高的增大，开采过程中更早出现断层活化，煤岩发生冲击失稳的风险增加。采动过程中，断层面上的剪应力呈现先缓慢增长后加速增长再突降的趋势，正应力呈现先缓慢上升后逐渐下降最终急剧下降的趋势。引入加卸载响应比，分析采动作用对断层的加卸载作用，形成了基于加卸载响应比的断层活化失稳预测方法和评价指标。研究成果能为大采高工作面的安全开采提供一定的理论支持。

Abstract: In response to the problem of coal and rock impact instability caused by fault activation during the process of mining through reverse fault in mining face with large cutting height, a numerical simulation software FLAC3D was used to construct a numerical model. The influence of mining on fault activation under different mining heights was compared and analyzed, and the changes in stress and displacement fields during the process of the activation and instability of the fault were discussed. Based on the theory of loading/unloading response ratio, the simulation results were analyzed and the criteria for determining fault instability were explored. The research results indicate that as the mining height increases, the degree of fault activation intensifies, and fault activation occurs earlier during the mining process, increasing the risk of coal and rock impact instability. During the mining process, the shear stress on the fault plane shows a trend of slow growth, accelerated growth, and then sudden decrease, while the normal stress shows a trend of slow rise, gradual decrease, and finally sharp decrease. By introducing the loading/unloading response ratio, the loading and unloading effects of mining on faults were analyzed, A fault activation instability prediction method and evaluation index based on loading/unloading response ratio have been developed. The research results can provide certain theoretical support for the safe mining of the mining face with large cutting height.