On June 30, the Shenzhen-Zhongshan Link Project, which took 7 years to construct, had been officially completed and opened to traffic. Integrating “bridge, artificial island, tunnel and underwater interchange”, the 24.03km long Shenzhen-Zhongshan Link is the world’s largest cross-sea cluster project. China Railway Shanhaiguan Bridge Group Co., Ltd. and China Railway Baoji Bridge Group Co., Ltd. affiliated to CRHIC have undertaken the steel box girder manufacturing tasks for contract sections G05 and G04 of the Project, including Shenzhen-Zhongshan Bridge (formerly Lingdingyang Bridge), Zhongshan Bridge, non-navigable channel bridge in Hengmen Flood Diversion Zone, non-navigable channel bridge in the West Flood Diversion Zone, non-navigable channel bridge in shallow water area, Wanqingsha Interchange Ramp Bridge and ancillary facilities, with a total length of 7.24 kilometers and a total weight of steel structure of 183,000 tons. 

The steel box girders adopted in this project are diverse in type, complex in structure, and challenging to manufacture. Focusing on solving common industry problems such as fatigue damage to the orthotropic bridge deck of steel box girders, CRHIC independently developed a series of new processes and equipment. This led to an improvement in production efficiency of over 30%, with stable weld quality and an average qualified rate of one-time flaw detection of over 99.9%. The one-time qualified rate for the full penetration welds of the top plate U-ribs exceeds 98% (2 percentage points higher than the Project target). To address the challenge of sectional manufacturing or slotted erection of large segments of non-navigable channel bridges in some shallow water areas, the Project team innovatively developed the scheme of steel box girder large segment offshore platform, broadening the way of transporting large segments through harbor basin. Since the commencement of plate unit manufacturing on June 20, 2020, the team has successively overcome many adverse factors such as typhoons and torrential rains, completing the manufacturing, shipment, and bridge connection of 135 steel box girder segments with high quality. They even set a record of completing an entire round of steel box girder assembly in 29 days.