Safety Evaluation Of Rock-Fill Dam By Seismic (Masw) And Resistivity Methods

Abstract

For safety evaluation of a rock-fill dam, it is often necessary to investigate spatial distribution<br>and dynamic characterization of weak zones such as fractures. For this purpose, both seismic and<br>electric methods are adopted together in this research. The former employs the multichannel analysis of<br>surface waves (MASW) method, and aims at the mapping of 2-D shear-wave velocity (Vs) profile along<br>the dam axis that can be associated with dynamic properties of filled materials. The latter is carried out<br>by DC-resistivity survey with a main purpose of mapping of spatial variations of physical properties of<br>dam materials. Results from both methods are compared in their signature of anomalous zones. In<br>addition, downhole seismic survey was carried out at three points within the seismic survey lines and<br>results by downhole seismic survey are compared with the MASW results. We conclude that the MASW<br>is an efficient method for dynamic characterization of dam-filling materials, and also that joint analyses<br>of these two seemingly unrelated methods can lead to an effective safety evaluation of rock-fill dam.