The Taizhou Bridge, Jiangsu, China
The Taizhou Bridge, China, has been awarded with the IABSE Outstanding Structure Award 2014 for being “A breakthrough in engineering and construction to span over large distances, the Taizhou Bridge ushers in a new generation of multiple-long-span, continuous suspension bridges”.
This Award recognises the most remarkable, innovative, creative or otherwise stimulating structure completed within the last few years. The Finalists were the ‘Kings Cross Western Concourse Roof’, UK; the ‘Canton Tower’, China and ‘Las Arenas’, Spain. The Outstanding Structure Award Committee 2014 was chaired by William Nugent, USA.
The Taizhou Bridge over the Yangtze River is the world’s first long-span, three-pylon, two-span suspension bridge and was opened to traffic in November 2012. It is a pivotal element of infrastructure in the east of China and will play a vital role as a link in the freeway network in Jiangsu Province and the Yangtze Delta region.
The spectacular suspension bridge has two continuous 1080 m main spans. It carries dual-six traffic lanes, with a deck with of 33m. The central pylon is of an inverted-Y shape on elevation, 200m tall, constructed in steel, and founded on a 58m by 44m caisson. The pylons at each end of the main bridge spans are concrete frame structures, 180 m tall, and each founded on 46 number 2.8 diameter friction poles.
All elements of the planning, design and construction have been determined to minimizing the ecological impact on the environment. The three-pylon two main span suspension bridge scheme was chosen for environmental reasons, as a means of minimising impact on the river hydraulics and ecology though reducing the number of bridge piers in the water while providing for two main navigation channels to facilitate ship movements and encourage the development of port facilities in the region. The scheme was also cost competitive given the site constraints and project conditions.
The structural behaviour of the suspension bridge system is different from that of a conventional two-pylon suspension bridge system. The design must ensure that no cable slip occurs over the cable saddles under all loading conditions, in order to prevent collapse. Conflicting demands on the central pylon stiffness therefore arise – a flexible central pylon helps prevent cable slip but is ineffective in the control of girder deflection; a stiff central pylon renders it difficult to help prevent cable slip, although it improves on deflection control of the girder. The main challenge issues are concentrated on the design of the middle pylon.
The Taizhou Bridge is high on aesthetic merits. The shape of the High-profile inverted Y-frame central pylon resembles the Chinese character for “human”, complimented by an aerodynamically efficient streamlined steel box girder deck, and a spectacular suspension cable profile. The silhouette is a stunning imagery night and day in all seasons. Its graceful and slender profile exudes simplicity and elegance and the bridge will become an iconic structure not only for China but also for the international scene.
The three pylon, two main span integral suspension bridge system has enabled not only a breakthrough in spanning over large distances, but also the beginning of a new generation of multiple-span continuous ultra-long-span bridges for conquering difficult terrains and obstacles.