Abstract
Conventionally, the safety management of fill dams is made by means of movement observation of embedded instruments in the dam body, or water level observation in the boreholes in the surrounding hill sides. But the data obtained from these instruments are only local point data, and not necessarily sufficient to identify the anomaly point. Authors developed new technique which could grasp the anomaly place as the change of resistivity by resistivity tomography. First, numerical experiment was excused to explore the sensitivity against anomaly point. Electrodes were buried in the fill dam during construction for measurement of resistivity tomography. In the result of resistivity monitoring during test filling of the dam, a little resistivity change was observed, which would be caused by seepage of reservoir water that had higher resistivity than underground water, or by changing of temperature in the dam body.
