| Project/Area Number |
03302043
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
土木構造
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
NAKAMURA Yasuharu Kyushu University, Research Institute for Applied Mechanics, Professor, 応用学研究所, 教授 (80038554)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAKE Akinobu National Technical College of Ariake, Assoc. Professor, 助教授 (40038104)
YOSHIMURA Takeshi Kyushu Sangyo University, Faculty of Engineering, Professor, 工学部, 教授 (80122612)
KUBO Yoshinobu Kyushu Institute of Technology, Faculty of Engineering, Assoc. Professor, 工学部, 助教授 (70093961)
MAEDA Junji Kyushu University, Faculty of Engineering, Assoc. Professor, 工学部, 助教授 (40128088)
OHYA Yuji Kyushu University, Research Institute for Applied Mechanics, Assoc. Professor, 応力研, 助教授 (00150524)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1991: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Keywords | Cable-stayed bridge / Aerodynamic instability / Flutter / Wind characteristics / Wind tunnel / Boundary layer control / Bridge section / Gust factor / 渦励振 |
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| Research Abstract |
1.The characteristics of gusty winds due to two typhoons, No.17 and 19 of 1991, passed through northern Kyushu are comparatively reported using the measurement records at 24 meteorological stations in Kyushu area. Gust factors at many of the stations exceeded 2 in both typhoons. The turbulent intensities at the stations were estimated to be more than 30%.
2.A new idea was discussed for improving aerodynamic instability of closed and open decks of PC cable- stayed bridge decks. The separation from a leeward separation point is controlled by a separated flow from a windward separation point. By using this method, non-streamlined shape deck can be chosen as the PC cable- stayed bridge girder and this method makes it possible to reduce the dead load of girder.
3.The stability of bridge girders was examined, and every girder satisfied the required wind speed in their wind resistant design. For suppressing galloping of a steel pylon, a tuned mass damper has been installed near its top since erection. Rain-wind induced vibrations of cables were observed on a bridge during construction, and a pair of oil dampers has been installed near the lower end of every cable.
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