5:15 PM - 6:45 PM
[SEM12-P07] Application of Timelapse ERT to Leakage Investigation in Dams
Keywords:Timelapse ERT, Dam leakage
The reservoir structures deteriorate with time and may be damaged during earthquakes. Current evaluation of dam safety relies primarily on visual inspection. If information such as the possible location, depth and inclination of the fault is available, it can improve the Water Resources Branch's understanding of the earthquake hazard and the possible impact of fault-related activities. There is also a sand layer under the dam foundation. This research completed the fault survey through a length above 1000 m measuring line and seepage monitoring of 400 meters upstream and downstream by electrical resistivity profiling(ERT) method. The monitoring period is from June to December 2012. According to the electrical stratigraphy results, there is no obvious trend that the fault appears below the dam body. However, there is obvious resistivity discontinuity in the dam body. According to the Timelapse ERT monitoring results from June to December 2012, there is no obvious change in the electrical strata of the dam body. Starting from October, the resistivity value from hot area has a slight downward trend. It is speculated that this should be related to the rise in reservoir water level and seepage in the sand layer.