REDUCTION OF VIBRATION DURING CONSTRUCTION OF BRIDGE TOWERS BY TMD

The wind-induced vibration of the bridge towers is detrimental to the safety of construction. In this paper, the Tuned Mass Damper (TMD) is used to reduce the wind-induced vibration. First, a vibration model of two freedom degrees is introduced to describe the mechanism of TMD by the relation of the vibration amplitude to both the parameters of TMD and the frequency of exterior excitation. Secondly, a simple method, which is based on the first eigen-frequency, is designed to compute the equivalent mass of the tower according to its first mode. A practical example about reduction of vibration of the large cable-stayed Yamen bridge is presented. It is demonstrated that the reduction of vibration by TMD to the tower of bridge is very effective despite the complicity involved in the design process.