Video: Ten-Thousand-Ton Cantilever Arms “Join Hands in Mid-Air” as World’s Longest-Span Steel Arch Bridge Closes Its Final Gap

Today, the steel truss arch of the Fenglai Daxi River Bridge on the Chongqing Wulong to Liangjiang New Area Expressway (hereafter referred to as the Wuliang Expressway) was successfully closed, marking a major milestone in the bridge’s construction with the conversion of the 10,000-ton cantilever system.

The Fenglai Daxi River Bridge on the Wuliang Expressway has a total length of 1,136.7 meters. The main bridge adopts a 580-meter deck-type steel box truss arch bridge, making it the world’s longest span steel arch bridge.

As a key and difficult control project along the entire route, the bridge features technical characteristics such as “super-large span, heavy-tonnage hoisting, and high-precision closure,” making it a typical representative of large-span steel truss arch bridge construction in mountainous areas of China.

The Fenglai Daxi River Bridge is located in the high, steep, and deeply incised canyon area of Wulong District. The bridge deck is over 310 meters above the river surface, equivalent to the height of a 100-story building. The entire bridge uses an all-steel structure with a total steel consumption of 25,000 tons. The largest single segment truss piece is 39.5 meters long, 18 meters high, and weighs 425 tons, equivalent to the height of a 6-story building and the weight of approximately 140 adult elephants.

Due to the high precision requirements for the alignment and stress of the super-large span arch bridge, the construction team broke through conventional arch bridge construction methods. For the first time, they adopted a construction philosophy of actively redistributing the stress in the upper and lower chords to form the arch, with dual control of stress and alignment. This overcame three core construction challenges: dual control of segment stress and alignment for the fully bolted steel truss arch bridge, adjustment of truss piece posture in limited space, and digital assembly of the arch rib with real-time alignment correction.

During the construction process, an innovative “prototype reset” assembly adjustment process was also adopted. This involved spatially matching the point cloud data models of the segment pre-assembly and the on-site bridge segments, significantly improving the construction accuracy and efficiency of the arch ribs.

Following the closure of the main arch, the 10,000-ton-level cantilever arch rib structure will complete the conversion of the force-bearing system, laying the foundation for subsequent superstructure construction and the full opening of the expressway.

The Wuliang Expressway starts from Pingqiao Town in Wulong in the west and connects to the Nanliang Expressway in the east, linking multiple areas including Wulong, Nanchuan, and Fuling. It has a total length of 36.7 kilometers. Upon completion, the Wuliang Expressway will directly shorten the travel time between Wulong and Liangjiang New Area by approximately 30 minutes, connect tourism resources such as Fairy Mountain and Baima Mountain, and promote development along the route.