Research on response of stress field in working face during the thrust fault activation process under mining disturbance

In order to analyze the change of the stress state of the working face under the coupling effect of mining disturbance and reverse fault, by means of numerical simulation, the slip tendency index Ts was introduced to comprehensively and quantitatively analyze the complex activation process of reverse faults in the mining process of footwall working face, and the influence of reverse faults on the stress state of working face under mining disturbance was obtained. The analysis results show that the reverse fault will undergo phase changes under the influence of mining disturbance, and it can be divided into three phases: quasi-static phase, activation phase, and slip dislocation phase. In the quasi-static phase,Ts value of the reverse fault is below the activation hazard base level, and the overall displacement vector of the reverse fault is upward along the fault. In the activation phase, Ts value of a small part of the reverse faultis up the activation hazard base level, and the slip direction of the partial fault area change from up to down along the fault. In the slip phase, most of the reverse fault plane is located above the activation danger base level, and the reverse fault slides downward in a large range. The influence of the fault on the bearing pressure of the working face is not obvious during the phase transition. But the change of the fault dip angle has a significant effect on the abutment pressure of the working face. The smaller the fault dip angle, the greater the concentration coefficient of the leading bearing pressure in the working face, and the easier it is to induce the occurrence of coal bumps.