In a coal company in Shanxi, the transient electromagnetic method is used to detect the 3202 back-mining face, and the purpose and task of the detection:
(1) To detect the water-richness of the face and the roof plate (within the range of 80) of the back-mining face;
(2) Explore the water-richness of the bottom plate of the face (within the range of 80);
(3) Find out the water-rich anomalous area on the top and bottom plates of the working face, and carry out targeted drainage and treatment of the water-rich anomalous area by drilling before mining back.
Figure 1 Schematic of the detection location (circled in blue)
There are 132 measuring points in the return air chute of 3202 working face, each measuring point detects three directions (15° diagonally upward, 45° diagonally upward, and 45° inward and downward), and 132 measuring points in the transportation chute of 3202 working face, each measuring point detects three directions (15° diagonally upward, 45° diagonally upward, and 45° inward and downward).
Figure 5-1 3202 working face on-site construction layout (magenta object detection points are launching points)
图2 3202回风顺槽瞬变电磁探测视电阻率剖面图
Figure 3 3202 Transient electromagnetic detection apparent resistivity profile of the return wind downwind trench
As can be seen from Fig. 2, the top plate shows low resistance (apparent resistivity below 10) up to 40m away, and there is a generalized low resistance response down to 60m away from the bottom plate, especially between measurement points 40-51 and 103-129, which are closer to the top plate and have obvious low resistance responses, with measurement points 40-51 about 30m away from the top plate, and measurement points 103-129 about 35m away from the top plate. The low resistance reaction between measuring points 40-51 is closer to the roof plate and the low resistance reaction is obvious.
As can be seen from Fig. 3, the top plate upward 40m away from the local low resistance (apparent resistivity are below 10), the bottom plate downward 60m away from the existence of local low-resistance reaction, especially in the 48-57 measuring points, 114-129 measuring points between the low-resistance reaction from the top plate is closer to the top plate, and the low-resistance reaction is obvious, 48-57 measuring points from the top plate of about 30m, measuring points 114-129 from the top plate of about 25m. The low resistance reaction is closer to the top plate and obvious.
4.Conclusion
The transient electromagnetic detection of 3202 working face detection area is analyzed by on-site measurement and data processing, combined with on-site situation and geological data, and two water-rich anomalous zones in the detection area are concluded:
Water-rich anomaly area A is located between measuring points 40-57, with anomaly depth of 30-70 meters upward in the roof; water-rich anomaly area B is located between measuring points 103-129, with anomaly depth of 25-70 meters upward in the roof; anomaly depths of 60m away from the downward direction of the bottom plate, which does not have much influence on the mining.
During the transient electromagnetic detection process, water has a greater impact on the detection, when measured on site, there is a general phenomenon of roof drenching from measuring point No. 90 to the cutting eye in the return wind tunnels, and there is a large amount of water between measuring points No. 7-9 in the transportation tunnels, which has a certain impact on the data collection.
Current position：
Mining Video Imaging Logging Instrument