What's special about the steel used for the Hong Kong-Zhuhai-Macao Bridge?

The construction innovation of the main bridge project of Hong Kong-Zhuhai-Macao Bridge is first manifested in the new breakthrough in the processing and manufacturing of the steel structure of the bridge deck. The steel structure manufacturing of Hong Kong-Zhuhai-Macao Bridge is divided into three stages: plate unit manufacturing, beam segment assembly and site connection. Various plate units that make up the bridge deck steel box girder are manufactured in Zhongtieshan Bridge, Wuchuan Heavy Industry, Shanghai Zhenhua and China Railway Baoqiao Base located in Shanhaiguan, Wuhan, Nantong and Yangzhou respectively, while the beam segment assembly and bridge deck steel box girder assembly base is located in Zhongshan. Breakthroughs in the processing and manufacturing technology of bridge slab steel structure include: realizing factory automatic production of slab unit processing, realizing "workshop-style" steel structure assembly operation, adopting horseless assembly technology, applying digital welding robot to steel structure assembly and manufacturing for the first time, adopting group control welding data management system, and equipped with modern sanding painting workshop matching production capacity.

On the other hand, the Hong Kong-Zhuhai-Macao Bridge steel box girder/composite beam assembly adopts the "long line method", which is the first in China to realize the "workshop-style" operation of large-scale bridge deck steel box girder assembly, greatly improving the production efficiency and ensuring the assembly quality and accuracy. Secondly, Fang Mingshan said that the overall prefabrication and assembly of the components of the Hong Kong-Zhuhai-Macao Bridge have also been improved. The assembly of the concrete structure of the Hong Kong-Zhuhai-Macao Bridge is to prefabricate the piers and caps into a whole, and then assemble them like building blocks. The Hong Kong-Zhuhai-Macao Bridge has taken another step in the overall assembly.

Wuchuan is built with about half of the steel structure of the main bridge, with a total weight of more than1.6000 tons, including the steel box girder on the bridge deck with a length of 7. 1.54 kilometers and the three main towers of the river-sea direct boat channel bridge. Among them, the Jianghai Direct Ship Channel Bridge is a three-tower cable-stayed bridge, which is one of the landmark buildings of the Hong Kong-Zhuhai-Macao Bridge. The installation height, weight and hoisting difficulty of steel tower crane are the first in China.

Steel structure is the "backbone" of the bridge, and its life directly affects the quality of the bridge. In the composition of steel box girder on bridge deck, the top plate of steel box girder is next to asphalt pavement. The roof directly bears the pavement pressure, and its quality restricts the quality of steel box girder. Previously, the roof thickness of China steel box girder was 10 mm, and that of Hong Kong-Zhuhai-Macao Bridge was 16 mm -20 mm, which was equivalent to "double roof".

The roof bears the pressure of the vehicle all the year round, and it is easy to get tired after a long time. For the first time in China, this military ship uses ultrasonic flaw detector to check the welding "wound", accurately locate the size and depth of tiny wound, and "treat the wound" pertinently, so as to improve the service life of steel box girder.