Parameters optimization test of mine transient electromagnetic method and application of advanced detection

In order to accurately detect the gob and the water-bearing area in advance, and ensure the safe excavation of the coal mine, the mine transient electromagnetic method was used to detect and compare the test in the known water-bearing gob, and the electric field response characteristics of different parameters to the mined-out gob were analyzed. A set of data acquisition parameters suitable for the detection of the water level, the number of superpositions and the acquisition density were optimized and the optimized parameters were applied to the practice of underground advance detection, the front gob and water-bearing gob area were successfully discovered. The results showed that the mine transient electromagnetic method used the emission frequency of 6.25 Hz, 32 superposition and medium density acquisition methods, and it was better to detect the gob and the water-bearing area; The acquisition optimization parameters were applied to the underground exploration in Jincheng Mining Area. Taking the advanced detection application of Wangtaipu mine as an example, it was seen that there was an obvious high-resistance anomaly and two low-resistance anomalies in front of the face, and the interface was obvious, which was basically the same as the identified distribution area of small coal mine roadway. After drilling and verification, the high-resistance anomaly area 50 m ahead of the front was empty, and it was found through the borehole fluoroscopy that it was a small coal mine gob and there was no water. When retreating 30 m backward, a low-resistance anomaly area was drilled to the right side, hitting a depth of 35 m with effluent, large amount of water, and the water was collected in the gob, which has a good detection effect. According to the exploration and summary experience of local coal mine in Ordos, Linfen local coal mine, Jinmei Group, Shuozhou local coal mine and other underground mines, the apparent resistivity value was generally below 30 Ω·m, which was inferred to be water-containing anomaly, and 30 Ω·m or more was inferred to be a normal rock formation without water, and higher than that would be inferred to be a high-resistance anomaly.