At about 5 May 14, Humen Bridge felt a strong earthquake, and then it was completely closed in both directions. On May 6th, Guangdong Communications Group reported that the Provincial Department of Transportation and the Provincial Communications Group organized 12 famous domestic bridge experts to hold a special video conference for evaluation.
According to the preliminary judgment of the expert group, the main reason for this vibration of Humen Bridge suspension bridge is that the aerodynamic shape of the steel box girder has been changed due to the continuous installation of water horses along the guardrail of the bridge span, and the bridge vortex vibration has occurred under specific wind environment conditions.
Experts also have a guess that it is related to the "damping ratio" of the bridge. Generally speaking, "damping ratio" is similar to virus antibody, which represents its ability to resist bridge vibration. The smaller the damping ratio, the lower the seismic capacity of the bridge. Humen bridge has existed for 25 years, and the damping ratio may become smaller, which will affect the anti-vortex vibration ability.
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Structural Safety of Humen Bridge
Recently, the bridge in China seems a little "floating". On April 26th, the bridge body of Wuhan Yingwuzhou Yangtze River Bridge swayed in the waves. Nine days later, a similar wave of "God Shake" came to the suspension bridge of Humen Bridge in Guangdong, which made the bridge "float" on the hot search.
The "blockbuster" of Humen Bridge in the vibrato video is really scary. However, experts say that although the bridge "floats" obviously, it is still safe.
Regarding the "flutter" of bridges, Zhengqing Chen, an academician of China Academy of Engineering, thinks that it can be divided into "dynamic" and "static" angles. When designing a bridge, the bearing capacity of the structure will be considered, that is, the maximum settlement of the bridge when it is fully loaded. It is estimated that the maximum subsidence of Humen Bridge is 2m, and the "floating" range of this bridge is about 0.5m.. From this static concept, the bridge is very safe.
People's Network-Expert: We must attach great importance to the vortex vibration of bridges.