2022 Fiscal Year Research-status Report
Experimental investigation on the adjustable wind barrier for the long-span strait bridge
| Project/Area Number |
22K14316
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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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| Keywords | Wind barrier / Long-span bridge / Aerodynamic stability / Travelling safety / Wind environment |
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| Outline of Annual Research Achievements |
Through the wind tunnel tests, this research investigated the effects of the wind barrier on the aerodynamic response and wind environment of two box girders: a bluff girder (width-to-height side ratio of 3.44) and a streamlined girder (side ratio of 7).
The aerodynamic response was not significantly affected by the wind-barrier section configuration or the opening shape. Increasing the porosity ratio significantly stabilized the wind-induced vibration because that increasing the porosity ratio significantly increased the turbulence intensity and decreased the vortex size on the girder according to PIV tests.
The wind barrier (porosity ratio 50%) can reduce the wind velocity on the streamlined girder by almost 50%, while it has limited effects on reducing it for the bluff one.
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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 two box girders of bluff type and streamlined type were clarified. Especially, the proposed wind barriers can stabilize the wind-induced vibrations of both two girders and reduce the wind velocity by 50% for the streamlined box girder. Additionally, the mechanism related to the effects of the wind barrier on the aerodynamic response was also clarified through PIV tests. Even though this mechanism needs to be clarified by more investigations, 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 box girders, the relationship between the wind-barrier parameters and the pressure distribution of the stationary and vibrating box girder is clarified through the wind tunnel tests. More specifically, it focuses on the vortex convection and the work of the surface pressure on the girder.
Meanwhile, the effects of the wind barrier on the aerodynamic performance and the wind environment of the truss girder are investigated through the wind tunnel tests to provide the wind barrier that can keep the girder aerodynamic stable and reduce the wind velocity on it by 50%. The related mechanism is clarified by PIV tests.
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| Causes of Carryover |
The reason for the incurring amount to be used next fiscal year is that the annual meeting of wind engineering was held online and the related travel fee was saved.
The incurring amount will be spent on English proofreading for the paper submitted to an international journal or buying books for research.
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