白鳥大橋主塔に見られた塔面内方向調和的限定振動の特性と風洞実験による再現

• Published in: Nihon Kaze Kōgakkai shi Vol. 41; no. 4; pp. 136 - 147
• Main Authors: 水谷, 司, 小林, 寿彦, 藤野, 陽三, シリンゴリンゴ, ・ ディオニシウス
• Format: Journal Article
• Language: Japanese
• Published: Tokyo 一般社団法人 日本風工学会 2016; Japan Science and Technology Agency
• Subjects: Coastal engineering; Pylons; Suspension bridges; Vibration; Wind direction; Wind shear; Wind tunnel experiments; Wind tunnels; Wind velocities; Japan
• ISSN: 1349-3507; 1349-340X
• DOI: 10.5359/jwe.41.136

This paper describes an along-wind vibration of frame-type pylons of Hakucho Suspension Bridge found from long-term vibration monitoring data. It is shown that the vibration is very harmonic although its amplitude is small and it occurs under certain ranges of wind direction (10~30 degree from the bridge perpendicular axis) and of wind velocity (13~25 m/s). The dominant frequency of the vibration is either 0.6 Hz or 0.8 Hz depending on the wind velocity and these correspond to the natural frequencies of the in-plane pylon dominant modes of the suspension bridge. A series of the wind tunnel experiments using a spring-supported scaled model are conducted under uniform flow and the along-wind pylon vibration was observed and its vibration characteristics is found to be consistent to those observed in Hakucho Bridge. It is also found that the vibration is very sensitive to the incident angle of wind and to the distance between the two columns.