Preliminary Research Of The Design Technology Of Self-Prestressed CFST Arch Bridge

In China Since the first CFST arch bridge, Wangchang East-river Bridge in Sichuan Province, was been constructed in 1990,The CFST arch bridge in our country are developed swiftly and violently by its so many merits such as construction simple , long span, and so on. The main span of the Wu Gorge Yangtze River Bridge already completed achieved 460 meters, The CFST arch bridge still develop toward the greater span, the large-scale direction at present, the region and the scope used was also expanding unceasingly.Although Concrete-filled steel tubular arch bridge widely used in China, its theory is still lagging behind the engineering practice, such as the cavity problem between steel tube and concrete. The cavity problem may make cause steel tube and concrete can not joint force, which is not match the basic assumption of good combination of steel tube and concrete at the design, and once the steel tube into the yield, low-stress state of concrete-filled steel tube can not exert its confinement effect affect the mechanical properties of concrete-filled steel tube to play, and even endanger the structural safety of concrete-filled steel tubular arch bridge become a major obstacle to further development. The stress in self-prestressed concrete-filled steel tube, can effectively prevent the cavity problem between steel tube and concrete ,and enhance the joint force of steel tube and concrete, so that make the actual situation of concrete-filled steel tubular arch bridge better conform to its design theory.Through a comparative analysis of the calculation method of arch rib stiffness of several main norms, determined put the concrete-filled steel tube as a combination of materials, to calculate the self-prestressed concrete-filled steel tubular arch rib stiffness is more reasonable.Through researching the damage mechanism of self-prestressed concrete-filled steel tube, used the research results of ordinary concrete-filled steel tube to solve the problem of self-prestressed concrete-filled steel tubular component, at the basic of the formula for calculating the ultimate bearing capacity of ordinary concrete-filled steel tubular compression member, derived from the formula for calculating the ultimate bearing capacity of self-prestressed concrete-filled steel tube compression member, and analyzed the relationship between the self-prestress value and the growth rate of the ultimate bearing capacity in detail; Concrete-filled steel tubular arch bridge in the atmosphere, directly under the sun, caused larger temperature difference. Through researching the temperature data of the concrete-filled steel tubular arch cross-section under the sunshine, revealed the role of temperature distribution of concrete-filled steel tubular arch rib section under the sunshine, using the derived formula to calculate, came up with a reasonable range of self-prestress and the expansion rate of core concrete.