Abstract:
Before the mining face mining in the underground coal mine, it is necessary to investigate the hydrogeological conditions inside the face using geophysical methods, which is the primary step in the "two explorations" for water prevention and control work. In order to ascertain the aquifer characteristics of the roof and floor layers inside the working face, this study adopts the combined interpretation of the transient electromagnetic method and the mine audio-frequency electric perspective method. Firstly, the principles and advantages and disadvantages of these two techniques are introduced, and the theoretical principles of their combined interpretation are analyzed to allow for mutual calibration and supplementation in engineering applications. Based on the engineering case of the 113 working face in Jinjitang Coal Mine, Inner Mongolia, the effective detection depth and the development range of anomalous areas in the contour section maps of the two methods are analyzed. Additionally, the horizontal and vertical development trends of anomalous areas in the three-dimensional visualization maps generated by the transient electromagnetic method, as well as the drilling verification results, are combined to draw the following conclusions: ① The transient electromagnetic method can improve the issue of poor layering in the audio-frequency electric perspective method; ② The audio-frequency electric perspective method can overcome the shortcomings of the transient electromagnetic method, such as poor anti-interference ability, shallow detection depth, and blind detection areas. These findings confirm the reliability of the joint interpretation of these two techniques.