## 4 Practical Application  
This part seeks to use the above-mentioned response law to direct the field detection and data interpretation of 3114 working face in Mataihao coal mine, thereby verifying the law's accuracy. According to the three-dimensional seismic data of the mine, the DF25 fault run through 3112, 3114, and 3116 working faces, the transport roadway of 3114 working face, and the return airway of 3116 working surface crossed the fault. To find out the distribution of water-rich area of DF25 fault near the transport roadway crossheading of 3114 working face and the return airway crossheading of 3116 working face, it is necessary to carry out underground TEM advanced detection of fault water-richness.  
The design height of the 3114 working face is 6 m, 31 coal is mined, the buried depth of the coal seam is about 387 m, the thickness of the coal seam is 6-7.7 m, and the average thickness is 6.53 m. The thickness of the coal seam roof is 164.07-255.13 m for Jurassic strata, and the average thickness is 187.47 m. The 3114 face coal seam has a crack-to-production ratio of around 27 times, meaning that when the working face is mined to a height of 6 m, the development height of the water-conducting fracture zone is 162 m. After the recovery of the 3114 working face, the water-conducting fracture zone developed in the Jurassic stability formation formation of the coal seam roof, and was not connected with the Cretaceous Zhidan group sandstone aquifer. The direct water filling source during the mining process of the 3114 working face is the sandstone fracture aquifer of the Yan'an Formation and Zhiluo Formation on the roof of the coal seam, the aquifer is weak in water richness, the normal water inrush of the working face is 100 m\({}^{3}\)/h, and the maximum inrush is 200 m\({}^{3}\)/h. The working surface is generally filled with low water intensity.  
Figure 11 is the result of advanced detection before grouting. In the pictures, the blue-green and yellow-red regions represent the low resistivity anomaly areas (relatively rich water area) and the relatively high resistivity areas (weak water area or no water area), respectively. In the  
Figure 10: Induced electromotive force attenuation curves of different dip angle collapse columns.  
direction of roof and layered detection, the abnormal area is located on the left side of the roadway 40 m-right side 40 m, detection direction 30-50 m. After the exploration, the mine conducted drilling design and construction combined with geophysical exploration results. During the drilling construction, the water yield of No. Z2-8 borehole in 3116 return airway was the largest, reaching 66 m\({}^{3}\)/h, and the water yield of other boreholes was 1-11 m\({}^{3}\)/h. The drilling water output area is in the low resistivity anomaly area delineated by mine transient electromagnetic.  
After determining the specific location of the water-bearing collapse column, multiple boreholes are arranged on the ground for grouting treatment to prevent flooding. When the grouting treatment is completed, the mine TEM was used again for detection. The detection results are shown in Figure 11. As shown in Figure 11, when there is a water-conducting structure, the resistivity value at the anomaly is reduced, and the contour distribution is distorted, deformed, or densely striped. Figure 12 showed that the isoline of apparent resistivity changes stably and uniformly without significant decrease. This showed that after grouting treatment, the collapse column and surrounding rock strata are fully integrated into the relevant electrical characteristics.  
Figure 11: Detection results before grouting.