Exploratory Seepage Detection in a Laboratory-Scale Earthen Dam Based on Distributed Temperature Sensing Method

The hydro-thermal coupled seepage condition assessment based on the fiber optic Distributed Temperature Sensing (DTS) is becoming popular, particularly in field-scale dams, due to DTS’s capability to provide spatially continuous temperature data. However, there is limited research examining this DTS’s capability in laboratory-scale dams due to the practical challenge of spatial resolution of the sensor. This study demonstrated and evaluated the applicability of spirally wound custom DTS in a laboratory-scale dam. By varying the reservoir water temperature, the DTS’s capability in capturing dam’s internal spatiotemporal temperature variations and detecting the seepage patterns was investigated. Thermal camera imaging and numerical modeling were additionally implemented to support and verify the laboratory findings. It was found that the DTS effectively captured the elevation-wise variability of temperature, seepage, and the location of phreatic line in the model dam. It was also observed that DTS may not necessarily reflect seepage conditions at the sensing location. Instead, it may provide general information about seepage conditions upstream of the sensing location.