Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

It has been reported that a conductive body can be often misinterpreted as a resistive one in cross-hole resistivity tomography using pole-pole array. In this study, both scale modeling and numerical modeling were carried out not only to get the responses of anomalous body, but also to compare them with respect to strike length of the body. In scale modeling for pole-pole array, an appropriate correction for measured data should be applied to compensate for the effects of remote electrodes. We used small acryl pipe to minimize the effects of remote potential electrode, while the correction for the remote current electrode was made in apparent resistivity calculation. In the case that the conductivity contrast between background medium and conductive body is lager than 100, 2.5-D inversion of cross-hole resistivity data could give a good image of conductive cylindrical body, of which strike length is not longer than 6 times of its diameter. But if 8 times or more, the conductive body was imaged as a resistive body. Secondary potential from numerical modeling showed that current channeling in conductive body caused it.