Source: Intuitive Learning Machinery (ID: Easy-machine), the article is compiled from: State-owned Assets Xiaoxin, People's Daily Online.
On August 4, the Anhaiwan Bridge of Fuxia High-speed Railway, designed and constructed by China Railway Construction, completed the construction of ballastless track, which is the first time in the construction process of high-speed rail in mainland China to achieve ballastless track laying on the cross-sea cable-stayed bridge, and it is expected that after the opening of traffic in 2023, the EMU will pass at a speed of 350 kilometers per hour to achieve the goal of high-speed rail crossing the sea without slowing down.
The Fuzhou-Xiamen high-speed railway has successively crossed Meizhou Bay, Quanzhou Bay and Anhai Bay, of which the Anhai Bay Bridge is 9.46 kilometers long and the cross-sea section is 1.56 kilometers long. It takes less than 7 seconds for the bullet train to cross the main body of the 650-meter bridge, how to realize the high-speed rail crossing the bridge without slowing down? Where is the "special" of the Ann Bay Bridge? Follow the editor to take a look!
How to realize high-speed rail crossing the sea without slowing down
It is understood that the high-speed rail track is divided into two forms: "ballasted" and "ballastless" track, compared with the flatness of the ballastless track is higher, the stability is stronger, and the train needs to slow down when passing through the "ballasted" track and "walking on the ground" through the "ballastless" track. However, due to technical bottlenecks, most of the domestic high-speed rail long-span bridges use ballasted tracks.
On long-span sea-crossing bridges, laying ballastless tracks and passing high-speed trains have extremely high requirements for bridge structural stiffness and dynamic performance. In order to clear the "speed limit point", the main girder of the Anhai Bay Bridge adopts effective pneumatic measures to reduce wind-induced vibration, and the bridge deck is paved with CRTS I. double-block ballastless track, which is more suitable for the large-span environment of the sea, ensures the span and takes into account the stiffness, and truly realizes the "seamless docking" of high-speed rail across the sea and land.
How difficult it is to install ballastless tracks on a sea-crossing bridge
Anhai Bay Bridge "large span" and "across the sea", there is no reference precedent for the ballastless track "on the bridge", the bearing motor car passes through the long-span bridge at a speed of 350 kilometers per hour, the ballastless track needs to bear the live load of the train, the temperature load and the bridge deformation and other multi-factor coupling effect, the bridge construction accuracy requirements are extremely high, and the builder should control the installation error of the steel anchor beam weighing up to 14 tons within 3 mm.
In addition, Ann Bay is located on the southeast coast, and the bridge is in a heavily corrosive marine environment, which is severely affected by waves and typhoons. In order to avoid the bridge from corroding the tower steel anchor beams and bearings, the construction team used marine atmospheric corrosion-resistant steel, which is one of the world's super steel technology cutting-edge steel grades, which can prevent the penetration of chloride ions in seawater and achieve the long-term anti-corrosion effect of "rust against rust".
In order to avoid the impact of monsoon and typhoon weather on the bridge in the southeast coastal area, the builders installed a large number of sensors on the bridge and adopted domestic dampers to "resist wind and maintain stability". When the cable-stayed cable encounters high-frequency vibration in strong winds, the damper can cancel the vibration and ensure the stability of the cable-stayed cable, so as to resist the rapid displacement caused by the earthquake, so that the train can pass the sea-crossing bridge at a speed of 350 kilometers per hour in a level 8 gale without a wind barrier, and will not close traffic under a level 11 storm.
"Take the high-speed train to see the sea" is about to be realized
The Fuzhou-Xiamen high-speed railway is the first cross-sea high-speed railway in China, with a design speed of 350 kilometers per hour and a total length of 277.42 kilometers, spanning three bays: Meizhou Bay, Quanzhou Bay and Anhai Bay, with a total of 8 stations. Up to now, the track laying of the Meizhou Bay Bridge has been completed, and the Quanzhou Bay Bridge is in the process of track laying.
Schematic diagram of the Fuzhou-Xiamen high-speed rail line
After it is completed and put into use in 2023, Fuzhou and Xiamen will form a "one-hour living circle", Xiamen, Zhangzhou, Quanzhou and other places will form a "half-hour traffic circle", and the southeast coastal urban agglomeration will be connected to a "golden tourism belt", which is of great significance for promoting the rapid development of the southeast coastal urban agglomeration.
Next, the editor will take you to understand the new stunts of China's high-speed rail!
In fact, as a professional team of sea-crossing bridges, infrastructure maniacs have been working hard for the desire to "see the sea by high-speed rail".
The longest sea-crossing bridge in China: Hong Kong-Zhuhai-Macao Bridge
On October 23, 2018, the Hong Kong-Zhuhai-Macao Bridge was officially opened by China Communications Group, China Railway, China Railway Construction, etc., which is the first super-large cross-sea traffic project jointly built by Guangdong, Hong Kong and Macao, known as the "Seven Wonders of the Modern World", and is the longest cross-sea bridge project in China's construction history, with the most investment and the most difficult construction, the world's longest sea-crossing bridge, the world's longest highway immersed tunnel, and the world's only deep-buried immersed tunnel.
The closest to the treasure island: the Pingtan Strait Highway and Railway Bridge of the Fuping Railway
On December 26, 2020, the Fuzhou-Pingtan Railway, which was constructed by China Railway and China Railway Construction, was officially put into operation. Pingtan Island in Fuzhou, Fujian Province, is only 68 nautical miles away from the treasure island of Taiwan, and is known as the most beautiful maritime high-speed railway in China.
China's first sea-crossing bridge: Donghai Bridge
The Donghai Bridge is the first real sea-crossing bridge in the mainland, and it is also the historic first step for the mainland bridge to move from the river to the sea. With a total length of 32.5 kilometers, it is constructed according to the two-way six-lane standard and has a design speed of 80 kilometers per hour, making it the first bridge in China to propose a 100-year design reference period.
On the blue deep sea, in the vast mountains, the builders have gathered sweat and wisdom to refresh the new level of mainland high-speed rail technology again and again, and promote the mainland high-speed rail bridge technology to the deep sea. I believe that in the future, more of our straits will be connected by such sea and sky routes, and truly change from moats to thoroughfares.
Beijing Shenzhou Xiangyu Technology Co., Ltd