Vibration Testing of Scaled Cable-Stayed Bridges

In this article, the development of a 1/75 dynamic small-scale model of the Hawkshaw Bridge and its modal identification are presented. The results are also compared with the vibration tests performed on the prototype structure. The Hawkshaw Bridge is a cable-stayed bridge in New Brunswick. The scaled model is 4.4 metres long compared to the actual length of 332 metres. The scale model was designed to stay within the elastic limits under the performed tests. Similitude laws were strictly followed to develop a structural model that complies with the dynamic similitude requirements. Random vibration sources were introduced to the scaled structure to simulate operational dynamic loads that the prototype structure experience. The response of the model was recorded using five tri- axial accelerometers. Using operational modal analysis, modal properties of the scaled model are estimated. The results were used to correlate the field vibration test data to the laboratory experiments.