Geophysical methods contributing to the testing of concrete dams. Application at the Marathon Dam

摘要

Geophysical investigations were conducted at the Marathon Dam site near Athens, Greece, in order to detect possible degraded areas that are potentially liable to water infiltration or leakage, and to evaluate the dynamic properties of the subsurface materials. The investigations were also extended in the dam interior in order to evaluate the quality of the concrete. This survey was necessary because the dam was hit by a strong (Ms=5.9) earthquake in 1999. The methods implemented included geoelectrical, seismic and GPR techniques. The potential of seismic methods to assess the dynamic properties of the material, the great dependence of electrical methods on the moisture content and the high resolving power of GPR in recognizing local structure anomalies proved to be the main contributing factors to the proper evaluation of the dam. The geophysical techniques also indicated a few suspicious parts in the dam that warrant close inspection by specialist engineers. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 13]