More than 20 years after its completion, it has won many innovation awards
What happened to the unusually shaking Humen Bridge
Our reporter Li Yan
On the afternoon of the 5th, the Humen Bridge in Guangdong was abnormally shaken. Many people in the past said that the entire bridge was undulating like a wave, causing heated discussions. Subsequently, the bridge management department closed the bridge.
It is understood that experts in related fields have rushed to the scene. After synthesizing the opinions of teachers such as Liu Chengyin, Xiao Yiqing and Gu Lei from Harbin Institute of Technology Shenzhen Campus, experts analyzed that the on-site wind speed reached about 8 meters per second, which caused the bridge amplitude vortex vibration (For finite amplitude vibration of vibration and forced vibration characteristics, its calculation of finite amplitude is a very important but extremely difficult problem).
It is reported that the Humen Bridge is under maintenance, and a 1.2-meter-high retaining wall has been added to the bridge deck to destroy the streamline of the section and cause vortex vibration. At present, the retaining wall is being demolished.
The Humen Bridge is the main component of the Guangzhou-Shenzhen-Zhuhai Expressway network, connecting the two banks of the Pearl River, connecting important cities such as Shenzhen and Zhuhai, and is an important transportation hub in the coastal areas of Guangdong. The Humen Bridge started construction in 1992 and was opened to traffic in 1997.
Humen Bridge is a national key project, many technologies have won innovation awards
The Humen Bridge, with an investment of nearly 3 billion yuan, is a national key project and the first truly large-scale modern suspension bridge in China. It has a large scale of construction, a novel structure, and is greatly affected by the external environment. Both design and construction are the first attempts in China, and have a special status in the history of bridges in China.
"Although the Humen Bridge is located in a typhoon-prone zone, this factor has been fully taken into account at the beginning of the design, and the wind resistance coefficient must be very high." Jia Yong, an architectural designer of Shenzhen Mobile Design Company, has long been engaged in bridge design, he told Technology A reporter from the Daily News, "The Humen Bridge has only been 20 years from now. Most of the bridges in China will be designed according to a 100-year plan."
During the construction of the Humen Bridge, China's long-span modern suspension bridge technology can be said to be a blank stage, and there are no ready-made construction technical standards and design specifications. From the later situation, Chinese engineers completed the design and construction work well. Because of this, the Humen Bridge project won not only the Zhan Tianyou Civil Engineering Award, but also several technologies won the Guangdong Science and Technology Progress Award and the National Science and Technology Progress Award.
The bridge real-time monitoring system is indispensable, but the maintenance is good or bad
The safety of bridges, including earthquake resistance and wind resistance, are key elements in design and construction. In order to understand the safety factors of bridges in real time, modern bridges generally have health monitoring and evaluation systems. This is a system that combines software and hardware to monitor and warn of cracks, waterways, traffic flow, environmental temperature, vibration and displacement of bridges in real time.
Industry insiders told Sci-Tech Daily that Humen Bridge also has a monitoring system that monitors the continuous displacement of the bridge in real time to understand the actual stress and working conditions of the bridge structure under various effects; at the same time, it is obtained by analyzing the monitoring results. The vibration parameters of the structure verify the wind and earthquake resistance design of the structure and realize the real-time monitoring of the safety of long-span bridges.
It is worth mentioning that this industry source said that the monitoring system of the building is not easy to maintain. Generally, software and hardware need to be updated in about 10 years. Some projects may not be replaced in time, but he also emphasized that bridge monitoring is The most important of all buildings, the monitoring system for important hubs like the Humen Bridge should keep running well.
The Tacoma Strait Bridge was destroyed by the breeze
For the unusual shaking of the Humen Bridge, many people initially believed that it was caused by the excessive wind speed of the main bridge at that time. However, some local people said that "the wind is not too strong." Speaking of which, there is really no wind in history, but the case of the bridge collapsed occurred. The most famous is that the Tacoma Strait Bridge collapsed in the breeze.
The Tacoma Strait Bridge is a suspension bridge located in Tacoma, Washington, USA. In 1940, the bridge suddenly collapsed 4 months after it was opened to traffic. According to records, the wind speed at that time was not large. It seems that such wind speed should not be a threat to the structure of the bridge, but the bridge was still destroyed by the breeze dramatically.
This collapse was considered to be caused by inadequate aerodynamics and structural analysis, which had a profound impact on the subsequent bridge design and construction. Later, all bridges, whether in whole or in part, had to pass strict mathematical analysis and wind tunnels. test. (Technology Daily Beijing May 5th)