## 6 Conclusions  
1. When sublevel 14 and sublevel 15 are continuously mined in the deep part of the main orebody, the mining influence range spreads to fault F2, and fault F2 is activated. With the passage of time, the slip increases gradually. In the process of mining the deep orebody of sublevel 16, the mining influence range spreads to fault F3, and fault F3 is also activated. As the deep mining continues downward, the slip amount is increasing. During the monitoring period, fault F4 did not generate activation dislocation.
2. Within 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. Moreover, 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 hangingwall of fault F2 also rotates along the right direction of the fault in the process of moving to the goaf; the main reason for this is that the west side is closer to the mining area.
3. 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. The additional tensile stress increases 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. 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, the fault plane will undergo shear failure, and the rock mass on both sides of the fault will lose stability, resulting in small dislocation or overall slip, which is also the essence of fault F2's and fault F3's activation.  
Conceptualization: Y.G.; methodology: Y.G. and L.L.; formal analysis: Y.G. and L.L.; writing--Original draft: Y.G.; writing--Review and editing: Y.G. and L.L.; resources: Y.G.; funding acquisition: Y.G.; validation: Y.G. and L.L. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the Scientific Research Fund Project of Yunnan Provincial Department of Education, China (no. 2022J0065); Key Projects of Analysis and Testing Fund of Kunming University of Science and Technology, China (no. 2021T20200145); China Postdoctoral Science Foundation Project (no. 2017M620433); and General Projects of Yunnan Fundamental Research Projects (no. 2018 FB075).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** Not applicable.  
**Conflicts of Interest:** The authors declare no conflict of interest.