APPLICATION OF ELECTRICAL RESISTIVITY IMAGING TECHNIQUES TO CIVIL & ENVIRONMENTAL PROBLEMS

The electrical resistivity method, which is one of the most widely practiced geophysical prospecting methods, has in the past usually been applied to groundwater and underground resource exploration. Its scope has recently been extended to civil and environmental areas because of new developments that allow it to image underground structures effectively. The applicability of the electrical resistivity imaging techniques to civil and environmental problems has been demonstrated in two case studies in Korea. First, the electrical resistivity surface imaging technique was performed in a tunnel construction site, to map the underground geological structure of a large area in a short period of time. The dimension of the weak zones was estimated and the support pattern of the tunnel was adjusted. The result was a successful excavation of the tunnel. Second, electrical resistivity tomography (ERT) was implemented in a research tunnel site to monitor the movement of brine after it was injected in a test borehole. A pair of low-conductivity zones that was interpreted as the pathway of the groundwater flow was clearly imaged.