In Chengdu, the new 295-metre Jiangxi River Bridge by Zaha Hadid Architects (ZHA) is now complete. Designed to accommodate vehicular traffic, cycling enthusiasts, and pedestrians, the bridge is the first of a series of bridges planned along Chengdu's reimagined West Line Road, which will form part of the Airport New Town Ring Road and Cycle Path in its redeveloped state.
Designed using sophisticated structural analysis software, the symmetrical bridge comprises two primary steel arches that rise from either side of the road deck. As the arches rise, they lean toward each other, touching tangentially at their crown and thus stabilizing the structure from lateral wind forces.
With a maximum height of 30 meters, the arches maintain a proportional relationship with an approximate 1:6 ratio, which is an ideal balance between the height and span of the bridge. Narrowing towards its centre, the bridge appears in the landscape as a dynamically curving and sculpted form.
The arches and their base are connected with longitudinal box girders integrated along the road deck's perimeters. Typically made from steel and concrete, box girders are often used where expansive spans are required, and a structure's inherent weight must be minimized. Positioning the box girders here also counteracts the horizontal pressure impacting the bridge.
Another interesting design aspect is the absence of foundations within the river the bridge spans. Instead, the bridge is supported by piers on opposite sides of the riverbank.
Many of the bridge's elements, such as the deck and the girders, were premanufactured. The deck was made of precast panels, and the edge box girder sections, which house cable anchorages, were also prefabricated and welded on-site.
These cable anchorages are large concrete structures placed far enough back from the water's edge to prevent the structure from sliding. These girders were transported to the construction site and linked to edge girders with bolted cover plate splices while mobile cranes lifted all the prefabricated steelwork and concrete parts. In-situ reinforced concrete was meanwhile used for constructing the bridge's bored piles and abutments.
The Chengdu West First Bridge crossing the Jiangxi River will open to the public upon completion of the West Line Road.
The Jiangxi River Bridge is one of the latest projects by Zaha Hadid Architects in China. Other recent regional projects include the Daxia Tower in Xi'an and the Wuhan Taikang Financial Centre.
