Research and application of multi-array mine DC electrical method for road-way advanced detection

The ANSYS finite element software is used to establish four full-space geoelectric models, and to per-form numerical simulations to the “U” observation mode of the pole-pole array, pole-dipole AMN and MNB arrays respectively.Then the inversion is carried out.The advanced detection effect of the two arrays is comprehensively analyzed, and the optimized device is applied to the field detection.The results show that the morphological char-acteristics of apparent resistivity are similar by comparing with the model with abnormal body in roadway.The overall apparent resistivity of roadway model is larger than that of model without roadway, which affects the delineation and identification of abnormal body in the detection results of AMN array.The model with abnormal body in a roadway is the most similar to the actual situation.The overall resistivity of AMN array is large, and the abnormal reflection is not obvious, so it is difficult to respond to the low resistivity body in front of the roadway.MNB array can respond to the low resistivity body, but the response range and position error are large.With the low resistivity body far away from the face, the abnormal signal reflection becomes less and less obvious, and the abnormal intensity and abnormal center become weaker and weaker.It is difficult to delineate the abnormal body, and the deviation from the actual position and size of the abnormal body is increasing.To a certain extent, the “U” observation mode of the pole-pole array can effectively respond to the low resistivity body and its position in front of the roadway.The response signal is stronger, and the abnormal amplitude intensity and center are more obvious.When the low resistance body is far away from the face and reaches 50 m, it can still be recognized.Through the detection of the water rich property of the fault in front of the driving roadway in a mine, the detection results show that the fault presents low resistivity anomaly.After drilling, it is a weak water rich fault filled with mud.Thus, the application effect of the pole-pole “U” type array is verified in advance detection of driving face.