Design and construction of Busan–Geoje fixed link, S. Korea Available to Purchase

This paper describes the construction of two major cable-stayed bridges on the 8·2 km long US$2·5 billion fixed link connecting Busan to Geoje Island on Korea's south coast. The 1·65 km two-pylon and the 1·87 km three-pylon cable-stayed bridges cross water depths of up to 30 m with main spans of 475 m and 2 × 230 m, respectively. The alignment takes an island-hopping route that is exposed to severe open sea conditions from the Pacific Ocean. To minimise off-shore working, large precast concrete units were used extensively for the sub-structures. This included placing 9600 t caissons, 1800 t pier shafts and 2080 t pier cross beams by floating crane. The prefabricated approach bridge superstructure spans up to 90 m long and 2427 t were also placed by floating crane. The pylons for the bridges are up to 158 m high and have a distinctive curved elevation. From the caisson, the two legs splay outwards until they reach the cross beam at deck level, where they lean back towards each other while both forming a large-radius curve. This imposes additional complexity on the construction but is considered to give enhanced appearance. Unusually, the deck has no vertical bearings at the pylon locations, instead being supported entirely by the cable stays. During superstructure construction, five sets of balanced cantilevers will be in simultaneous use and temporary typhoon stabilising measures will be the major risk management challenge. Completion is due in December 2010.