Seismic tomography tests applied to a gravity dam

Abstract

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 be used in existing dams to evaluate the materials (strength properties) and to verify if they match design expectations, as well as to contribute to the safety control. In particular seismics methods can considerably contribute to the examination indicating the less consolidated material and the degradation of mechanical parameters. For the characterization of the concrete conservation three seismic tomographies and a vertical seismic profile on the dam body were performed.The vertical seismic profile showed P-wave velocity ranging between 3800 m/s 4750 m/s and S-wave velocity ranging between 1100 m/s and 2520 m/s. Also in this case lower values are present in the upper part of the dam body, as well as show the three seismic tomographies. Even Poisson ratios show typical values of the concrete in good condition, varying between 0.29 and 0.41 (at the upper part of the dam body), which are representative values for concrete.