- Volume 21 Issue 1
For the purpose of maintenance and prevention of earth fill dams against damage from natural hazards, automatic monitoring through various measuring instruments and resistivity survey has been carried out. Reservoirs and embankments have the structural vulnerability on the agricultural usages since most of them were built more than thirty years ago. The main aim to use monitoring method is to verify the safety and integrity of the dam. Resistivity survey can detect potential weaknesses, such as defective zones, anomalous seepages or internal erosion processes. Permanent resistivity monitoring systems were installed at a reservoir, which daily measurements have been taken every 6 hour. Using monitoring data for one year, anomalous seepage and structural defects were clarified for dam safety. Annual water level fluctuations are around 10 m. During their operation, reservoir dams are subject to a never-ending hydraulic load from the reservoir, which over the years may cause changes in the properties of the inner parts of the dam construction. Detailed analysis of the monitoring results was performed and showed that resistivities at most locations have been very stable over the full monitoring period excluding the effects of water fluctuation and seasons. To investigate the detectability of weak zone using the DC resistivity monitoring, numerical modeling with a simplified model for the drainage at a reservoir dam was also performed. The results showed that the seepage zone near drainage in a reservoir dam could be detected by resistivity response change.
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- Korea rural community cooperation, 2016, Statistical yearbook of agricultural production infrastructure maintenance, 2015 Ed. (in Korean).
- Park, S. G., Kim, J.-H., and Seo, G. W., 2005, Application of electrical resistivity monitoring technique to maintenance of embankments, Geophys. and Geophys. Explor., 8, 177-183 (in Korean with English abstract).
- Sjoahl, P., Dahlin, T., and Johansson, S., 2004, Resistivity monitoring for internal erosion detection at Halby embankment dam, Procs. Int. Conf. on Environ. Eng. Geoph., Wuhan, China, 6-9.
- Song, S. H., Song, Y. H., and Kwon, B. D., 2005, Application of hydrogeological and geophysical methods to delineate leakage pathways in an earth fill dam, Explor. Geophys., 36, 92-96. https://doi.org/10.1071/EG05092
- Yi, M.-J., Kim, J.-H., Song, Y., and chung, S.-H., 2000, Dam seepage using two-and three-dimensional resistivity surveys, Proceeding of the 2nd Special Symposium of KSEG, 41-53 (in Korean with English abstract).