At 285 metres high, a span of 380 metres and a width of 16 metres, this new bridge is the largest double-arch bridge in the world, breaking other records during its construction.
The bridge consists of two back-to-back concrete-filled steel tubular spans of about 380 to 504 metres, if measured between the centre of the beams. Each “rib” forming the structure allegedly weights up to 200 tonnes (200,000 kilos).
The Shuangbao Bridge’s six-lane structure, covering a width of 16 metres, crosses the Dadonhge and Xiaohegou rivers in a W-shaped canyon of the Chongqing district, China. The construction of the bridge was incredibly difficult due to the karst geography in the region – a type of landscape in which dissolving bedrock creates sinkholes, caves and sinking streams.
As a result, the project required extensive on-site exploration and measurements, as well as comprehensive consideration of various complex conditions, including the stress the bridge would place on the geological conditions.
Once operational, it is said that the bridge will save from 40 minutes to an hour on journeys from the central city of Chongqing to Youyang and Xiushan in China.
On top of breaking the record for the largest double-arch bridge in the world, the No.2 Public Transport Bureau of the China Communications Construction Company also said it used the “world’s first cable crane span of independent cranes,” during construction, with a 900-metre span and 167-metre height, which received the “the world’s first cable lifting weight of the same structure”.
This type of advanced technology had not previously been used in China before. It also used an intelligent active balance support system to eliminate the imbalance of forces, and applied digital pre-assembly technology for the first time. This was based on 3D laser scanning and creation of point clouds on the segments and ribs of the arches, which saved significant time in the final assembly with an accuracy at millimetre level.
Prior to the bridge’s construction, a temporary suspended chain bridge, with a span of over 245 metres, was installed which attracted a lot of media attention, with photographs and video clips showing 40 to 50-tonne trucks driving along the single-lane track as if walking on a tightrope.
In December 2023, the two arches were connected and the bridge was declared to be in the final stages of completion.
Once completed, Yuxiang dual carriageway “will greatly relieve traffic pressure on the existing motorway, further improve the logistics and passenger transport network in southeast Chongqing, and provide supporting infrastructure for the development of local ecological agriculture, tourism and other ecological industries,” according to Chongqing Municipal Bureau of Transportation through People’s Daily Online.
