Abstract
This paper deals with a newly developed damper, called a keel damper, used to reduce bridge vibration caused by wind or vehicles passing over it. It was installed in two-girder bridge of span lengths 60m, and the vibration testing was carried out. The damping characteristic of the bridge was greatly improved by this damper. It was confirmed to have the high performance for not only first and but also second mode in which the frequency widely separated, moreover for minute vibration. As a result of investigating the temperature dependency of the performance, the characteristic agreed with the analysis comparatively well.
