Composite material bridges anti-collision devices

Recently, Chongqing City government decided to apply those soft bridge anti-collision device in 5 bridges within the city’s jurisdiction as well as the provinces of Fujian and Guangdong.

According to the introduction of Mr. Geng Bo, director of bridge research & development center of the CCTRDI bridge branch, there are many bridge-boat collisions accidents across the Chongqing jurisdiction. At present only 3% to 5% bridges in China that has installed anti-collision devices. Because there is limitation of the materials selections, most of those devices used in the bridges across China have applied steels as the raw materials. The new type of bridge anti-collision devices developed by the CCTRDI bridge branch bridge R & D center has for the first time applied the high elastic fiber reinforced composite materials in the bridge anti-collision field.

It has been reported that this bridge anti-collision device has designed according to the Chinese Tai Chi concept of shoving a thousand cattle with four tales. When the boat yawing away from the course and colliding with the bridge, the soft bridge anti-collision device will not allow the shock wave generated by the collision to transform into the bridge pier directly.

The anti-collision device can allow the boat to have the turning time and space and utilized the water current lifting effect to push the boat away from the bridge pier, so that the boat can slide away from the outside of the anti-collision device, which gives double protection to both of the bridge and the boats.

According to Geng Bo, this device has been designed three types including self-floating soft anti-collision boxed cofferdam, fixed soft anti-collision fender, and fixed soft anti-collision board. All of those three types are made of composite materials with good flexibility, high energy absorption rate, and high buffering effects.

After many time testing, compare with the traditional anti-collision devices made of materials such as steels, and rubbers, the bridge anti-collision device they have developed can at least reduce about 40% boat colliding impact, while the steel device can only reduce about 10% to 20% boat colliding impact.

In respect to the service life, the composite material anti-collision device can increase about 2 to 3 times as long as that of the traditional material devices made of steels or rubbers. The service life without maintenance can last at least 25 years.

The bridge with such soft anti-collision devices, the damage will be greatly reduced during the boat colliding accident. “Because this kind of device has applied modular design and installation, which is equivalent to children’s block building game that can be built with many different shape components. This method not only can increase the production and construction efficiency, but also can ease the future maintenance work after the boat collision. Only those blocks that have been damaged during the collision or over the time need to be changed with the other blocks intact.” Geng Bo told reporters.

In addition, each of the different type devices has its own unique characteristics: for the self-floating soft anti-collision boxed cofferdam, except anti-collision functions, it can automatically change the protection height based on the river current level changes. Even after partial damaging, it can still floating with the water level and continues its bridge protection functions. This type of anti-collision device is especially suitable for the bridges in the mountainous rivers with large water level height difference and fast flaw rate during the flood season. For the bridges of the river with small water level height difference, the other two types of devices can be applied.

According to Geng Bo, the above anti-collision devices have applied more than 10 patents including 3 invention patents. At present, they are preparing to apply these devices in 5 bridges in Chongqing, Fujian, and Guangdong.

More information:www.cmct.cn – www.ctin.ac.cn
Original language Chinese