| 摘要 |
PROBLEM TO BE SOLVED: To improve attenuation efficiency of torsional vibration of a girder of a suspension bridge. SOLUTION: A hanger 2 suspended from a cable 1 is not anchored directly to a girder 3 and, instead, anchored through a vibration-damping device having attenuating function. The vibration-damping device comprises a member 4 provided rotatably with a pin attached to the girder 3 as a shaft and a high attenuation rubber sandwiched between the member 4 and the girder 3. If a torsional angleθoccurs at the girder 3 in the process of the occurrence of torsional vibration to the girder 3, the hanger 2 almost kept to a vertical posture since the hanger 2 is subjected to a tension 5 by the gravity of the girder 3. At this time, the member 4 is restricted by a tension 5 of the hanger 2, so that the member 4 rotates with the pin as the shaft and is held at the position on a straight line with the hanger 2. Thus, a relative torsional angleθoccurs between the hanger 2 and girder 3 and the member 4 and girder 3. Shear deformation by the torsional angleθoccurs in the high attenuating rubber, so that the energy is dissipated by this shear deformation and torsional attenuation of the girder 3 is kept to a high level. |
