Detection of defects in dikes by frequency domain electro-magnetic sounding

摘要

The principle of Type EM34-3 Ground Conductivity Meter based on Frequency Domain Electro-Magnetic Method (FEM) and its application in detection of hidden defects in dikes are introduced. The instrument was used in seven dams and three dikes for detecting and locating the hidden defects and leakage paths. In this paper, we only presented the calibration at Nishan Reservoir and the detection result with this device in Damaojiahu dike and Zhongzhouyuan dike. This instrument can directly measure the apparent conductivity of ground in the depth of 7.5m, 15m, 30m, and 60m, respectively.