The fast inversion for advanced detection using DC resistivity in tunnel
坑道直流电阻率法超前探测的快速反演

The place of the anomalous extremum of apparent resistivity curve is related to the position, thickness, resistivity and occurrence of geologic bodies ahead of the tunnel. It's indispensable to design an effective method to invert for multiple parameters of the geologic body synthetically. Firstly, we make numerical modeling analysis with finite element method and eliminate the effect of tunnel-cavity, translate the apparent resistivity curve of advanced detection in tunnel into the curve in full space. Then inversion of the advanced detection is caried out by least square method. The result shows that the electric property and position and occurrence of anomalous body, the resistivity of bed rock, can be obtained correctly; however only the composite value of resistivity and thickness of anomalous body can be determined because of equivalence.