Investigations of Erosion of Concrete in a Dam Using Seismic Tomography and Surface Waves

The results of investigations of the erosion of concrete walls of the Kruonis hydroaccumulation electrical power plant dam (Lithuania) using seismic tomography and surface waves are considered. A layered structure of near-surface concrete layer of the dam retaining wall was identified. Zones of the concrete surface, mostly subject to erosion at the contact with water, are outlined by low velocity anomalies. A zone of water leakage from the upper power plant reservoir is localised and its spatial boundaries are determined.