ABSTRACT
In Concrete Filled Steel Tubes (CFST) structures, the in-filled concrete delays local buckling of the steel tube, while the steel tube reinforces the concrete to resist tension stresses and improve its compression strength and ductility. Moreover, in construction, the tube also acts as a formwork for the concrete. The first two CFST arch bridges were built in the USSR in 1930s and 1940s. Since 1990, many CFST arch bridges have been building in China. Up to March 2005, more than 230 CFST arch bridges, with the span over 50 m, have been built or are under construction (Chen 2004, 2007a & 2007b). Among them, 131 bridges have a main span longer than 100 m and 33 significant bridges with a span greater than 200 m. In the following, all of the analyses are based on the data of CFST arch bridges with a span equal to or longer than 100 m.
