Seismic Investigation for the Characterization of a Gravity Concrete Dam

Monitoring of large-scale infrastructures plays an important role for public safety and prevention. The control of the safety assessment of a dam is largely dependent on knowledge of the mechanical parameters of the actual construction, as well as its geological substratum. The application of geophysical methods can considerably contribute to the examination indicating the less consolidated material and the degradation of mechanical parameters. A seismic tomographic approach has been used in a typical gravity concrete dam without reinforcement to detect mechanical properties of the body of the dam and its geological setting. Three seismic travel time tomographies in the dam body as well as S-wave velocity values obtained by a down hole testify that the dam is composed of high quality concrete. Small variations on the P-wave velocities seem to be the effect of moisture and infiltration. In addition seismic surveys in the surrounding grounds of the dam confirmed the expected properties of the foundation terrain.