Vortex vibration of Zhoushan No.1 Bridge in Zhejiang Province

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 Vortex vibration of Zhoushan No.1 Bridge in Zhejiang Province


On the evening of June 18, a short-time vortex induced resonance occurred in Xihoumen sea crossing bridge, Zhoushan. The transport department called in relevant experts to respond today:

This phenomenon will not affect the safety of bridge structure.

It is reported that there have been many similar phenomena around the world. Although there have never been casualties, what exactly is vortex induced resonance? Is our bridge really safe?

If the professional positioning is used to explain, when the air flows through the structure, the regular vortex will be generated due to the influence of the shape of components, wind speed and other conditions. If the vortex is close to the natural frequency of the structure, vortex induced resonance will occur.

Dr. Tian Hao, director of the Institute of bridge and tunnel engineering, Zhejiang Academy of Transportation Sciences, who has been involved in the research of vortex induced resonance for a long time, gives an example,

Just like a knife in the water, the water will ripple. The bridge exists in the air, and the wind will vibrate, but the vibration of the wind cannot be seen by the naked eye.

In short, the most intuitive feeling of vortex induced resonance is that the bridge is shaking under the wind, and the upper and lower parts of the bridge deck swing like waves. At this time, driving may not be so comfortable, which is one of the reasons for the short-term closure of the bridge after vortex induced vibration of Xihoumen Bridge.

It is understood that Xihoumen Bridge is a large-span suspension bridge designed and constructed by ourselves in China. When it was completed in December 2009, it was the worlds largest span steel box girder suspension bridge. Vortex vibration monitoring system is installed on the bridge, which can judge the safety of the bridge in real time. Since Xihoumen Bridge was built and opened to traffic, vortex vibration has been monitored 20-30 times a year, lasting 10-300 minutes each time, and the amplitude of acceleration and displacement are within the allowable range of the code.

In fact, not only Xihoumen Bridge, but also important bridges with special structures in our province are equipped with special bridge health monitoring system, which can continuously monitor the bridge condition for 24 hours. As long as the data is abnormal, relevant measures will be taken.

(function(){( window.slotbydup=window .slotbydup||[]).push({id:u6056789,container:ssp_ 6056789, async:true }Dr. Tian Hao said that the phenomenon of vortex induced resonance must be faced by the bridge construction. In recent years, the code also has corresponding provisions for vortex induced resonance, and some bridges at home and abroad have relatively mature experience. Therefore, the design, construction and management of bridges in the province will be fully considered. Through the comparison of the main beam stress, main beam deformation, main cable force and other key data before and after the previous vortex induced vibration of Xihoumen Bridge, the acceleration and displacement amplitude of this vortex vibration are within the allowable range of the specification, which will not cause the strength damage of the structure, and the possibility of fatigue damage of the components is also small, so it will not affect the safety of the bridge structure, please rest assured. In addition, the transportation department also reminds you, if you encounter vortex induced resonance, do not panic, keep the distance from the car in front, and pass at normal speed. Relevant recommendations: a bridge across the sea in Zhejiang Province is subject to short-term vortex vibration due to strong wind. A man suspected of hanging himself on the bridge in Zhoushan, Zhejiang Province has no vital signs. Source: urban express author: Huang Yuxuan editor in charge: Yao Yu_ NBJS10892

Dr. Tian Hao said that the phenomenon of vortex induced resonance is something that bridge construction must face. In recent years, the code also has corresponding provisions for vortex induced resonance, and some bridges at home and abroad have relatively mature experience in handling it. Therefore, the design, construction and management of bridges in the province will be fully considered.

Through the comparison of the main beam stress, main beam deformation, main cable force and other key data before and after the previous vortex induced vibration of Xihoumen Bridge, the acceleration and displacement amplitude of this vortex vibration are within the allowable range of the specification, which will not cause the strength damage of the structure, and the possibility of fatigue damage of the components is also small, so it will not affect the safety of the bridge structure, please rest assured.

In addition, the transportation department also reminds you, if you encounter vortex induced resonance, do not panic, keep the distance from the car in front, and pass at normal speed.