采动诱发应力主轴偏转对断层稳定性影响分析

为探究上、下盘不同开采顺序对断层稳定性影响，基于压力拱理论提出应力偏转概念，运用FLAC3D数值方法，模拟工作面分别从断层上盘和下盘向断层推进的过程，分析接触面应力状态和演化规律，验证采动诱发应力偏转，并与断层损伤变量及其增速进行对比分析。研究表明，工作面自上、下盘不同方向靠近断层，顶板主应力起始偏转位置分别为距离断层120 m和40 m处，相差80 m，且下盘最大偏转角是上盘工作面的1.68倍；断层损伤变量的启滑点分别距断层130 m和40 m，下盘工作面相对上盘工作面提前90 m，二者良好的对应关系表明应力偏转与断层滑移失稳显著相关。采动诱发应力偏转产生附加应力概念可以很好解释上、下盘工作面断层稳定性差异，为断层保护煤柱留设及工作面过断层防灾措施制定提供新思路。

Analysis of the mining induced stress rotation influence on fault stability

To explore the influence of different mining sequences on the fault stability, this paper put forward the hypothesis of stress rotation based on pressure arch theory. Firstly, a numerical model was set up to simulate the process of working face passing through the fault from the hanging wall and footwall to the fault. And then it analyzed the stress state and evolution law of contact surface, and verified the stress rotation induced by mining. Finally, comparative analysis of the fault damage variables and their growth rates was carried in this paper. The results show that during the propulsion process of working face from different directions of hanging wall and footwall of fault, the distance between start position of principal stress rotation in roof and fault is 120 m and 40 m, respectively. The maximum value of principal stress deflection angle when the working face located at footwall is 1.68 times than the value when located at hanging wall. The starting slip points of fault damage variables are 130 m and 40 m from fault, respectively. The fine correspondence between them indicates that stress rotation is significantly related to fault slip instability. The caption of additional stress induced by stress rotation can well explain the difference of fault stability due to different mining sequences, and provide new ideas for the design of fault coal pillar and disaster prevention measures.