| Project/Area Number |
22K14316
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| Research Category |
Grant-in-Aid for Early-Career Scientists
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| Allocation Type | Multi-year Fund |
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| Review Section |
Basic Section 22020:Structure engineering and earthquake engineering-related
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| Research Institution | Yokohama National University |
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Principal Investigator |
王 嘉奇 横浜国立大学, 大学院都市イノベーション研究院, 助教 (20902274)
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| Project Period (FY) |
2022-04-01 – 2025-03-31
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| Project Status |
Granted (Fiscal Year 2023)
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| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2024: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2023: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2022: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
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| Keywords | Wind barrier / Long-span bridge / Aerodynamic performance / Vortex-induced vibration / Vehicle safety / Bluff box girder / Aerodynamic stability / Travelling safety / Wind environment |
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| Outline of Research at the Start |
The safety of the vehicles on the long-span bridges against the strong winds has been the main concern. Even though traffic regulation is applied, wind-induced traffic accidents still frequently occur. The wind barrier is most effective to protect the vehicles by directly reducing their wind-induced forces, but it potentially results in the unallowable wind-induced vibrations of the bridge. Therefore, this research intends to develop the wind barrier that can guarantee the safety of the vehicles and stability of the bridge against wind-induced vibrations.
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| Outline of Annual Research Achievements |
To develop the wind barrier to guarantee the aerodynamic stability of both the bridge and the running vehicle on it, the below research based on wind tunnel tests was carried out. 1) We investigated the effects of the wind barrier on the aerodynamic response and wind environment of a bluff box girder. The wind barrier made the girder a larger amplitude of vortex-induced vibration than the bare girder. 2) We further investigated the mechanism of the abovementioned response using a rectangular cylinder. The wind barrier of 50% porosity ratio and with a triangle-section bar successfully stabilized the aerodynamic response to be the same as the bare girder. Additionally, the important role of the upside and downside surfaces of the bluff girder in its response is clarified.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Through a series of wind tunnel tests, the effects of the wind-barrier parameters on the aerodynamic performance and wind environment of a streamlined box girder, two bluff box girders, and a rectangular cylinder were clarified. Especially, the proposed wind barrier can stabilize the wind-induced vibrations of the abovementioned girders. Additionally, different from the streamlined box girder, the important role of the upside and downside surface of the bluff box girder in stabilizing the wind-induced vibration is clarified. The whole research can be evaluated as ‘making good progress’.
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| Strategy for Future Research Activity |
To further investigate the mechanism related to the effects of the wind barrier on the aerodynamic response of the streamlined and bluff box girders, the relationship between the wind-barrier parameters and the aerodynamic damping/work distribution of the vibrating girder will be investigated through pressure measurement of the girder in the wind tunnel.
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