Study On Response Characteristics Of Time Domain Induced Polarization Field Of Mine

Based on the theory and characteristics of ground induced polarization method,as a supplement to mine geophysical prospecting method,this paper studies the characteristics of time domain response of anomalies under the condition of mine geology by ways of numerical simulation and physical model experiments.high resistivity coal seam can enhance the induced polarization response of abnormal body,especially the low resistivity anomalies and the tunneling(water-bearing)structure.Under the background of the half-space with tunnel and full-space,this paper compares and analyzes the response characteristics of induced polarization about different depths of high and low resistivity sphere and different angle plate body,and the typical anomalous body effectively(collapse column、fracture zone、aquifer、coal gab area).The simulated results show that the whole space background are in accord with the general characteristics of low resistance having high polarization and high resistance having low polarization.The closer the anomalous body is to the power supply point and the line distance,the greater the polarizability.The shape and the extreme value of the polarization curves of the different angles plate in the background of the full-space are consistent with those of the half-space background.Coal seams(high resistivity)and tunnels can enhance the induced polarization response of abnormal body,especially the low resistivity anomalies and the tunneling(water-bearing)structure.Summing up the response characteristics of induced polarization about the same geological anomaly in different positions by combinations of polar observation methods,it has following rules: no matter the power supply of the top,bottom or side of the tunnel,the results mainly reflect the induced polarization response of the abnormal body in the direction of the alignment;for the two-tunnel work-face floor with water body,the power supply measurement of different lane is greater than that of the same power supply;meanwhile,supplying electricity in one tunnel’s floor and jointly measuring in two tunnel’s floor,which can be used to determine the location of the abnormal floor.The maximum values of the polarizability curves of the physical model can well correspond to the main geological structures and abnormal body positions in the model,which is in agreement with part of the simulation.Therefore,it is proved that time domain induced polarization method can effectively detect abnormal bodies in mine geological conditions.