On August 6, 2021, China Communications Second Navigation Bureau undertook the construction of the first cross-sea high-speed rail bridge in China-Fuzhou-Xiamen (Men) High-speed Rail Quanzhou Bay Cross-sea Bridge successfully completed the main bridge closure, and China's high-speed rail entered the era of sea-crossing. .

The newly built Fuzhou-Xiamen high-speed rail project is located in the coastal area of Fujian Province, starting from Fuzhou in the north, and reaching Xiamen and Zhangzhou in the south. The main line is 277.42 kilometers long and has a design speed of 350 kilometers per hour. It is China's first cross-sea high-speed railway line in the true sense. 

Among them, the sixth bid section undertaken by CCCC Second Aviation Administration is the most difficult bid section for the entire line. The route starts from the Taiwanese Investment Zone of Quanzhou City and crosses Quanzhou Bay into Jinjiang City. The total length is 27.455 kilometers, including key control projects across the line— —Quanzhou Bay Sea-Crossing Bridge. The sea bridge is 8.96 kilometers long. The main bridge spanning Quanzhou Bay is 800 meters long and the main span is 400 meters. The sea high-speed railway bridge is also the world's first long-span cable-stayed bridge across the sea with a traveling speed exceeding 300 km/h.

The main girder of Quanzhou Bay Cross-sea Bridge adopts the form of steel box girder, which is divided into 13 types and 77 sections, of which the heaviest girder section weighs 365.18 tons. According to Weng Fangwen, chief engineer of the Fuxia Railway Project of the Second Aviation Administration of China Communications, the steel box girder of the final closing section that was installed on the same day, the single beam section is 10 meters long, 21 meters wide, 4.25 meters high, and weighs more than 240 tons. The length and ambient temperature influence on the site operation of the closure. In order to facilitate the flexible control of the closure time, the mid-span closure adopts the "active" closure method of hoisting on the north side and pushing on the south side, achieving millimeter-level precision control.

Facing the high wind, water depth, large waves, high tidal range, high salinity, high humidity and other marine environmental conditions in the bridge area, as well as the series of challenges in the seismic high intensity area on the west bank of the Straits, the Fuxia high-speed railway design unit China Railway Construction Railway Fourth Institute and China Construction units such as the Second Navigation Bureau of Jiaotong University have carried out joint technical research to overcome the passage of high-speed rail trains on long and long sea-crossing bridges in strong winds, long-term corrosion resistance and durability of high-speed rail sea-crossing bridges in high-salt, high-humidity and corrosive environments, and long-connected high piers in areas with high seismic intensity The seismic resistance of sea-crossing bridges and the adaptation of long-span long-span bridges on the sea to the laying of ballastless tracks have realized three major issues: railway steel-concrete composite beam cable-stayed bridges, unsupported monolithic rigid-frame bridges, and marine atmospheric corrosion-resistant steel structures. Major innovations and breakthroughs in the technological system.

In order to realize the coordination between the bridge form and the bay environment and make the bridge a landmark bridge in Quanzhou Bay, the Fourth Railway Academy and the Academy of Fine Arts have carried out a special landscape design. The pylons of the bridge are integrated with marine elements, adopting shell-shaped curved pylons, taking into account the reasonable structure and architectural aesthetics, and recreating the historical glory of "Song and Yuan China's world marine trade center". Next to the Quanzhou Bay Bridge on the Fuzhou-Xiamen High-speed Railway is the Quanzhou Ring-City Expressway Cross-sea Bridge that opened to traffic in 2015. The closest distance between the two bridges is only 28.7 meters. Quanzhou Bay will show the beautiful sea scenery of the two bridges.

Yan Aiguo, chief engineer of the Bridge Institute of the Fourth Academy of China Railway Construction, said that the main bridge of the Quanzhou Bay Cross-sea Bridge was successfully closed, marking the opening of the key control nodes of the Fuxia high-speed rail line, and the entire line construction has entered the final sprint period. "The completion of the bridge will usher in the world's high-speed rail sea-crossing era and promote the technological development of China's large-span high-speed rail and sea-crossing bridges." Yan Aiguo emphasized.

Keywords: engineering construction, engineering news, engineering construction information

It is reported that the Fuzhou-Xiamen high-speed rail, as an important extension of the Beijing-Fuzhou high-speed rail, is planned to be completed and opened to traffic in 2022. By then, Fuzhou and Xiamen will achieve a "one-hour living circle". At the same time, the completion of the Fu-Xia high-speed railway will effectively solve the problem of railway "bottleneck" constraints in the southeast coastal areas of China, and will be of great significance for promoting Fujian's rapid integration into the national high-speed railway network and accelerating the economic and social development of the Haixi urban agglomeration. Editor/Sang Xiaomei