The 12th International Conference on Scour and Erosion (ICSE 2025)

Earth dams, encompassing embankments, dikes, and levees (EDL), are vital infrastructure for irrigation, flood control, hydropower, and both domestic and commercial water supply. However, they are highly susceptible to internal erosion—a process where fine soil particles are transported by seepage through the dam due to cracks and deformations, excessive pore water pressure, or unstable soil gradations. The initiation phase of internal erosion often goes undetected due to lack of external manifestations which can lead to dam breach as the erosion moves quite fast to progressive phases. Therefore, regular monitoring of earth dams is crucial to detect the development of internal erosion at early stages. Prevalent active geophysical monitoring methods, such as electrical resistivity tomography, ground-penetrating radar, and induced potential methods, focus on seepage detection rather than detecting the initiation of internal erosion. Investigating emerging continuous passive monitoring techniques that continuously capture subtle signs of internal erosion at early stages is essential to prevent catastrophic breaches in earth dams. The study investigates these techniques through the development of a small-scale physical model of an embankment dam. The initiation of internal erosion is induced by a crack in the conduit pipe installed inside the dam's body. The dam is monitored using passive seismic sensors stationed at the crest and downstream slope of the earth dam, fiber optic sensors, pore pressure transducers and piezoelectric transducers embedded in the earth dam. The initiation of internal erosion generates a micro-seismic event with low frequency waves followed by high frequency acoustic events during the continuation phase of internal erosion. The captured seismo-acoustic waves are processed for impulse response reconstruction. Time-frequency feature extraction and wavelet analysis are adopted to assess the time and locus of internal erosion initiation. The proposed approach provides a novel method for early detection of internal erosion in earth dams.