Yong Jong Grand Suspension Bridge, Korea

The Yong Jong Grand Bridge in South Korea is part of the new road and rail links between Seoul and the new Inchon International Airport now being constructed. The main design principles of the bridge were function, symbolic expression of Korean culture, and visual harmony with the surrounding environment. The 4.42km long bridge has an upper deck carrying a six-lane highway, and a lower deck carrying a four-lane highway and two railway lines. The main part of the bridge is its 550m long suspension bridge, with 300m main span, two 125m side spans, and a 60m cable sag. It is one of the few self-anchored suspension bridges that have yet been built. It has 35m clearance above the sea, steel box girders for its decks, and 104m diamond-shaped steel towers, whose wind-resistance properties were tested using a 1:150 scale model. The main cables are shaped in three dimensions. The bridge's design wind speed is 40m/s. The approach viaducts have a double-deck truss configuration with three-span continuous sections; each span is 125m long and 36.1m wide. The whole superstructure, which is almost all made of steel, is being constructed on steel bents. Cables will be erected on top of the superstructure, which they will then support. By April 1998, about 40% of the construction work had been completed.