China News Agency, Guangzhou, May 6 (Cai Minjie) An unusual jittering incident occurred at the Humen Bridge in Guangdong, which aroused public attention. Zhang Xinmin, deputy chief engineer of Humen Bridge, said on the 6th that the current vortex vibration has no impact on the structural safety of the bridge. As of press time, the bridge was still shaking.
At 16 o'clock that day, the reporter was 200 to 300 meters away from the Humen Bridge, and felt that the wind at the scene was relatively strong, and the river surface turned up. More than a dozen bridge experts conducted test and evaluation work on the Humen Bridge.
It can be seen from the surveillance video of the Humen Bridge Management Center that at 15:50 on the 5th, the water horses along the bridge's side rails began to be removed, and they were removed at 17:42.
The reporter saw from the Humen Bridge Management Center that the "Main Bridge Jitter Record" shows that from 15:28 on the 5th, the main bridge of the Humen Bridge has been shaking, but the magnitude of the shaking is different. On-site staff said that, for example, the jitter amplitude increased from 8:35 to 12:20 on the 6th, but weakened again from 12:20 to 15:32. As of press time, the bridge jitter was weak and invisible to the naked eye.
Zhang Xinmin said that due to the influence of wind and inertia, a structure will not stop immediately after vibration, but the energy consumption can eventually be eliminated. At present, vortex vibration has no effect on the structural safety of the bridge.
The Humen Bridge is a cross-sea bridge connecting Nansha District of Guangzhou City and Humen Town of Dongguan City in Guangdong Province. It connects the two sides of the Pearl River and communicates with important cities such as Shenzhen and Zhuhai. It is an important transportation hub in coastal areas of Guangdong. The Humen Bridge started construction in 1992 and was opened to traffic in 1997.
Due to the large traffic volume and long-term overload operation of the Humen Bridge, the six bridge sections of the bridge have different degrees of disease. Therefore, since August last year, control and maintenance have been implemented to prohibit trucks and passenger cars with more than 40 passengers from passing through the Humen Bridge throughout the day.
According to Zhang Xinmin, according to the experience at home and abroad, generally large bridges will undergo operation and maintenance after 20 years. In general, the cause of the vibration of the Humen Bridge this time also includes the long-term high-load operation of the bridge, plus the bridge is at the estuary, where the salt and fresh water converge, the environment in which it is corroded is severe.
On the 5th, the Humen Bridge was abnormally shaken, the suspension bridge deck swayed relatively large, and the amplitude was relatively obvious, which caused discomfort to the traffic. In order to ensure traffic safety, Guangzhou and Dongguan traffic police have taken traffic control measures on that day and closed the two-way traffic of the suspension bridge. On the 6th, Guangdong Provincial Communications Group stated that according to the preliminary judgment of the expert group, the main reason for the vibration of the suspension bridge of Humen Bridge is that the continuous installation of water horses along the span of the bridge changes the aerodynamic shape of the steel box girder under certain wind conditions. , The phenomenon of bridge vortex vibration.
The expert group said that the large-span suspension bridge has vortex vibration at low wind speed, and the vibration amplitude is small, which is not easy to detect. Only under special conditions will it produce larger amplitude, which will not affect the safety of the bridge structure, and will affect the driving experience and comfort. , Easy to induce traffic safety accidents. (Finish)