저수지 누수유로 파악을 위한 측선간 전기비저항 토모그래피

Abstract

Resistivity method is one of the most effective techniques for the detection of anomalous seepage intervals in the embankment dam. Generally, resistivity data acquired along the crest of an embankment have been interpreted by assuming that the embankment dam has a 2-dimensional (2D) structure. Because the structure of the embankment dam is not 2D, there should be inevitable limitations in the interpretation of resistivity data. Even though resistivity method is a powerful tool to detect anomalous seepage intervals in the embankment dam, it is too difficult to locate anomalous seepage pathways completely since the seepage flow is not always straight. In this study, we present a new 2D resistivity modeling technique which assumes 2D structure with infinite extent along z-direction. This technique has the feature that makes us deal with the x- and y-directional variation of resistivity easily at the expense of giving up the z-directional variation of resistivity. Therefore, this technique has the advantage that the clay core, the reservoir water and etc can be easily included in the 2D resistivity modeling of the embankment dam. Also, we developed a crossline tomography method which can give a resistivity image in the x-y plane. The resistivity image is effective to identify anomalous seepage pathways in the embankment dam.