A major advancement has been made on the Shizi Yang Passage, a core transportation hub in the Guangdong-Hong Kong-Macao Greater Bay Area, with the successful closure of the steel truss girder bridge crossing the Xiqiao Waterway. Eleven prefabricated segments were meticulously assembled and connected on September 12, marking a critical step in the bridge's construction. This particular structure is recognized as the largest single-span double-deck steel truss girder currently under construction in mainland China.
The Shizi Yang Passage is another massive cross-river project in the Greater Bay Area, following in the footsteps of the Hong Kong-Zhuhai-Macao Bridge and the Shenzhen-Zhongshan Link. The passage spans approximately 35 kilometers, connecting Nansha District in Guangzhou with the towns of Humen and Shatian in Dongguan. The main engineering works consist of the Shizi Yang Bridge, the project's flagship river-crossing structure, and approach roads on both banks.
The Xiqiao Waterway bridge features a main span of 165 meters, making it the largest single-span double-deck steel truss girder in mainland China, and its design accommodates inland Class II navigation standards. The steel truss girder measures 41 meters in width and stands about 15 meters high, with a total weight of 8,100 tonnes. The entire structure is divided into 11 segments, akin to 11 giant "building blocks," which are intelligently prefabricated in factories and then transported to the site for precise assembly.
Construction faced significant logistical hurdles due to the presence of basic farmland on both banks of the waterway, which restricted land transport. The tidal range in the Xiqiao Waterway reaches 3 meters, and the limited navigation clearance of surrounding bridges meant that oversized and overweight components could not be transported in one piece. More critically, this project's double-deck steel truss girder has the longest span of its kind in mainland China, requiring a steel usage of 50 tonnes per linear meter—the highest design metric of its type. The bridge's large width and immense weight greatly increase the load on temporary support structures, rendering traditional step-by-step incremental launching methods unsuitable. Furthermore, due to navigation constraints, there was insufficient space to deploy extensive temporary water-based support systems, making construction organization exceptionally challenging.
To overcome these obstacles, the construction team adopted an innovative approach using "water-based prefabricated lifting and floating-box rotation techniques." The large steel beams were divided into smaller components, transported to the site in batches, and then lifted and assembled section-by-section using floating cranes, effectively solving the issues of transporting large components and limited shore-side space. Additionally, the team independently developed and designed a "modular floating-box component rotation device." This device enables the safe and smooth flipping of 400-tonne steel components without relying on large shore-based cranes, greatly improving both safety and efficiency. This method provides a replicable technical solution for similar water-crossing bridge construction projects.
Currently, construction on the Shizi Yang Passage is progressing steadily. The main Shizi Yang Bridge is in the process of erecting its catwalk, while the approach sections are installing steel truss girders and launching box girders. Overall, the project is more than halfway complete. Once fully opened to traffic in 2029, the Shizi Yang Passage will horizontally connect the three major metropolitan circles of the Greater Bay Area, linking the eastern and western wings of Guangdong Province. It will further densify the core transportation network of the "Golden Inner Bay," providing a powerful impetus for the integrated and coordinated development of the Greater Bay Area.