Vibration analysis and modal identification of a circular cable-stayed footbridge

Abstract

Vibration measurements and modal identification were performed on a footbridge as part of the commissioning tests. The deck presents a circular configuration, in plant, and is suspended from eight cables connecting it to the extremity of a steel mast anchored to a concrete bulk situated on the riverside. The dynamic measurements were aimed to control the force installed in the cables during the tension operation and to characterize the dynamic parameters through output-only modal identification techniques in order to calibrate a Finite Element model. At last, groups of pedestrians crossed the bridge at various speeds allowing conclusions about the vibration amplitudes that can be expected during real use of the bridge.