Infrared thermography based seepage and erosion detection in earthen dams using laboratory scale models.

Early and precise seepage detection is crucial for maintaining the safety and integrity of dams and preventing potential disasters associated with dam failure. This study focuses on detecting seepage in earthen dams using an infrared thermography-based approach, a non-invasive and non-contact technique. The seepage phenomenon was recreated on a laboratory-scale model of an earthen dam with two distinct downstream surfaces: one with soil cover and the other with grass turfing. Extensive infrared thermography analysis indicated that temperature variations could serve as key indicators for seepage identification. Results revealed an interesting pattern with temperatures at seepage locations being either lower or higher than the surrounding soil depending on the time of imaging. The latter typically occurs after 14:30 h. when solar loading is below 800 watts/m. For the earthen embankment geometry considered (side slopes of 1 V:1.87 H), camera viewing angles between 45° and 55° were found optimal, as temperature measurements from the infrared camera closely matched spot readings from installed thermal sensors. Additionally, experiments on downstream surfaces with varying surface erosion depths revealed significant temperature gradients in infrared images, with areas of severe erosion displaying marked differences compared to regions with minimal erosion. The findings encourage the broader use of infrared thermography for detecting seepage and erosion in earthen dams.