Study on response characteristics of 2D transient electromagnetic of non-water-conducting fault structure

The hidden non-water-conducting fault in front of the coal mining face is a potential accident potential danger in the coal mining site, so it needs to be studied in detail. Firstly, the forward calculation formula of 2D transient electromagnetic is introduced and solved by finite element numerical calculation method. The numerical results are in good agreement with the analytical results. Secondly, a 2D geological model with fault structure and without fault structure is established, and the model is numerically calculated. The research shows that the response law of the induced magnetic field contour to high resistivity fault structure is obvious, and the shape and scope of the contour distortion are in good agreement with the position, direction and dip angle of the fault in the model. With the decrease of the distance between the location of measuring point and the fault, the amplitude of the induced electromotive force response shows an increasing trend in the early sampling period, but the minimum amplitude of the tip response gradually increases, and the amplitude of the tip response concave with the fault model is larger than that without the fault model. The apparent resistivity imaging results can better reflect the electrical characteristics of the high blocking layer and the coal-bearing strata, indicating that the forward modeling results are accurate and reliable.