Cross-sea bridges pillar of stability for high-speed rail

The two main tower piers are built on the ocean where the depth of water can reach a maximum 20 meters. Construction of temporary facilities such as trestles, platforms, and steel cofferdams is difficult due to the slope of the large rock mass or exposed bedrock, as well as fast currents, according to the constructor.

The company adopted the advanced Building Information Modeling technology to stimulate constructing process and visualize possibility of collision or other situations, to have acquired key data before construction.

The Quanzhou Bay Bridge, with a total length of 20.3 kilometers, is the first cross-sea high-speed rail bridge in China. To tackle the difficulty in lifting and precisely positioning box girders on the sea, the constructor, CCCC Second Harbor Engineering, set up a three-dimensional scene for bridge closure construction, arranged a data collection network based on cloud intelligence of things on site, and used high-precision sensors to obtain key parameters, said Liu Fuxing, who was in charge of the project from the company.

"We have solved the difficulties of manual observation and temperature variation at the closure mouth. In the end, the deviation of the bridge closure axis was only 1 millimeter, with a relative height difference of 0.5 mm," Liu added.

In response to the high salt spray environment in the Quanzhou Bay area, which requires high corrosion resistance of steel, the bridge has, for the first time in China, applied non-coated nickel-based weather resistant steel materials to steel anchor beams anchored by stay cables. The "protective clothing" achieved a technological breakthrough in long-term corrosion protection throughout their entire lifespan, according to the company.