Modal identification of concrete dams with different typologies under natural excitation

Abstract

The Laboratory of Vibrations and Structural Monitoring (ViBest) of FEUP is presently responsible by the development of the research project DAM-AGE (Advanced Online Dynamic Structural Health Monitoring of Concrete Dams). One of the first tasks of this project consists on the performance of ambient vibration tests on concrete dams with different typologies and stiffness characteristics and on the application of state of art output-only modal identification methods, getting better sensitivity to the problems raised by the very low collected signals (of the order of micro g) when dealing with such massive structures. In this context, this paper describes a set of ambient vibration tests performed on different Portuguese concrete dams and presents the most relevant modal estimates obtained with the application of modern output-only modal identification techniques, stressing the good level of accuracy in general achieved, despite the very unfavourable signal-to-noise ratio in comparison with other civil engineering applications. (c) 2019 International Group of Operational Modal Analysis.