## 5 Monitoring and Activation Law Analysis of the Fault Activation Slip
### Regularity Analysis of Fault Activation Slip Based on Monitoring Results  
According to the monitoring data of fault activation dislocation displacement for more than four and a half years and the monitoring results of stress change in the surrounding rock of the hangingwall and footwall of the fault, the following conclusions can be drawn by comprehensive analysis:  
1. From the relative relationship between the fault and the location of the mining area and the slip failure of the fault, it can be concluded that fault F2, fault F3, and fault F4 in the footwall of the main orebody are normal faults; that is, the hangingwall of the fault has moved to the goaf or there is a trend to move to the goaf. Under the influence of deep mining, the normal stress on fault F2's and fault F3's planes decreases, and the shear strength decreases. When the shear stress is greater than the shear strength, movement and failure to the goaf will occur. 2. During the mining of the orebody in sublevel 14 and sublevel 15, fault F2 was activated as the mining influence area developed to fault F2. With the passage of time, the slip amount of fault F2 gradually increased, and the cumulative slip amount reached 1.56 m. In the process of mining the orebody in sublevel 16 of the deep part, the mining influence range is spread to fault F3, and fault F3 is also activated. At present, the place with the largest accumulative slip amount is 27.27 cm, and with the continuous downward mining in the deep part, the slip amount is increasing. The monitoring data showed that activation dislocation did not occur at fault F4, indicating that the mining influence range did not reach fault F4. 3. From the monitoring data results, in the same monitoring time, the monitoring displacement of the multipoint displacement meter in the lower sublevel is greater than that in the upper sublevel, and the displacement of the measuring point near the goaf is greater than that far from the goaf, indicating that the movement of the fault is transmitted from bottom to top, and the distance from the mining area is developed from near to far. The fault activation sequence is from fault F2 to fault F3 and then to fault F4. In addition, for fault F2, at the same monitoring time, the displacement of the measuring point on the west side of the fault is larger than that on the east side of the fault, indicating that the rotation of the hangingwall of fault F2 along the right direction of the fault occurs in the process of moving to the goaf. From the stress-displacement curve with time combined with the large blasting time of the footwall of the main orebody, it can be concluded that blasting vibration has a certain influence on the fault activation. 4. From the stress monitoring results, when the mining influence range spreads to the fault, additional tensile stress perpendicular to the fault plane and additional shear stress along the dip direction of the fault plane are produced in the surrounding rock of the hangingwall and footwall of the fault and increase with the increase in the mining influence range. At the same monitoring position, the additional shear stress is greater than the additional tensile stress, and the stress change value of the surrounding rock of the hangingwall of the fault is greater than that of the footwall, indicating that the existence of the fault has a certain barrier effect on the propagation of stress. It also shows that, when the influence range of underground mining affects the fault, the increase in additional tensile stress on the fault plane will reduce the shear strength of the fault and increase the slip of the fault. When the shear stress exceeds the shear strength of the fault plane, shear failure occurs on the fault plane, and the rock mass on both sides of the fault loses stability, resulting in small dislocation or overall slip, which is the essence of fault F2's and fault F3's activation. From the monitoring results, fault F4 has not yet been activated. 5.