## 5 Monitoring and Activation Law Analysis of the Fault Activation Slip
### Displacement Analysis
#### 5.1.2 Analysis of Displacement Monitoring Data  
According to the previous survey results, all faults to be monitored are normal faults. Therefore, this monitoring adopts two anchor head multipoint displacement meters. When installing the monitoring instrument, try to ensure that the multipoint displacement meter sensor and the shorter anchor head are located in footwall of the fault, and the deeper anchor head crosses the fault and is located in hangingwall of the fault. The results are processed based on the monitoring data; since the deep anchor head moves together with the fault during the movement of the hangingwall of the fault toward the goal, the displacement measured by the deeper anchor head is the fault dislocation displacement, while the shorter anchor head and sensor are located in the footwall, which are relatively immobile, so the readings are within the normal error range and in the immobile state. Therefore, the displacement measured by the measuring point on the hangingwall of the fault crossing the fault is the fault slip displacement. The multipoint displacement meter monitoring curve of fault F2 is shown in Figure 10. Since 25 July 2011, the monitoring displacement of the multipoint displacement meter at each measuring point of fault F2 has gradually exceeded the range; therefore, after 25 July 2011, the observation of fault F2 was mainly conducted by the mark line observation method. The mark line measuring point is located in the exposed area of fault F2 in sublevel 12. Two points with better conditions are selected to set up the mark line observation. The data are read every three months. The slip of fault F2 observed by the marker line observation method is shown in Figure 11. Figures 12 and 13 show the multipoint displacement meter monitoring curve of fault F3 and fault F4, respectively. The monitoring period was from November 2010 to April 2015. The mining elevation is from sublevel 14 to the end of sublevel 15, and the stoping of deep orebody in sublevel 16 and the development of sublevel 17 are currently underway. The main results of the observation are as follows:  
1. As of 25 July 2011, the cumulative displacement of each measuring point for monitoring fault F2 is: W11-1 is 291.2 mm, W11-2 is 332.3 mm, W12-1 is 350.4 mm, W12-2 is 374.1 mm, W13-1 is 385.3 mm, and W13-2 is 400.5 mm. During the monitoring period, the average cumulative movement of fault F2 is 355.6 mm, and the average movement rate is 1.36 mm/d. As of 14 April 2015, the fault F2 mark line monitoring, cumulative fault slip of measuring point BZXI is 1.45 m, and the cumulative fault slip of measuring point BZX2 is 1.56 m. The cumulative slip of each measuring point of fault F3 is: W11-5 is 21.33 cm, W12-3 is 22.13 cm, W12-4 is 25.16 cm, W13-3 is 25.188 cm, W13-4 is 27.00 cm, W14-1 is 27.26 cm, and W14-2 is 27.27 cm. The displacement values of each measuring point used for monitoring fault F4 are as follows: W10-1 is 0.021 mm, W11-6 is 0.024 mm, W11-7 is 0.038 mm, and W12-5 is 0.072 mm. 2. From the trend of the slip-time curves of the three faults, the moving rate of fault F2 is relatively large. After the fault activation under the influence of deep mining, the cumulative slip is the largest, reaching 1.56 m. Fault F3 has also activated and slipped under the influence of mining, and the cumulative displacement of the measuring point with a large slip is 27.27 cm. The measuring point with the largest displacement of fault F4 is W11-6, and the displacement is 0.072 mm. The displacement value is small and within the normal error range, indicating that fault F4 has not been activated. 3. According to the monitoring results, during 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 goat is greater than that far away from the goat, indicating that the movement of the fault propagates from the bottom to the top.