Study On Stability Influence Factors Of Long-span Concrete-filled Steel Tubular Arch Bridge

Due to high bearing capacity, span, sleek, linear and smooth, convenient construction and many other advantages, CFST Arch Bridge will appear by the people’s love and favor, so the bridge has been widely used in road construction in China. With the continuous development of concrete filled steel tube arch bridge design theory and construction technology, Such bridges are more gentle as the span increases. The stability of CFST Arch Bridge has become increasingly evident and complicated. Existing theory can not fully meet the actual needs of the modern concrete filled steel tube arch bridge design and construction. Many bridges occur instability failure at home and abroad. Research of Long Span CFST Arch Bridge stability has become one of the important issues to be solved in such bridge design and construction.This thesis focused on the factors influencing the stability of long-span CFST Arch Bridge, which based on a span CFST Arch Bridge. This paper mainly discusses the effect of the following factors on the stability of CFST Arch Bridge, which draw the relevant conclusions.1. Number of rungs arranged. With the gradual increase in the number of rungs, the arch bridge of safety factor is gradually increased, and Arch Bridge of plane stiffness gradually increases.2. Rungs layout position. The analysis results show that the arch near rungs have greater impact on arch stability safety factor than the vault near rungs.3. The rungs style. K words support play a greater role in the increase stability of the arch bridge than the word support, and the K word support at different locations play the varying degrees of impact on the stability of the arch bridge.4. Span ratio. When the span ratio changes in the range of1/7to1/4, the stability factor of CFST arch bridge is increased as the span ratio increases, and maximum appears within the range of1/4.5to1/4. When the arch’s span ratio exceed1/4, the arch bridge’s stability factor has declined as the span ratio increases; and nonlinearity have a great impact on different span ratio of arch bridge. 5. The radius to thickness ratio. The analysis results show that with the gradually increasing diameter to thickness ratio, the stability factor of CFST Arch Bridge show degradation; And nonlinearity have a great impact on different radius to thickness ratio of arch bridge.6. Rib rigid. The stability of the arch bridge is enhanced with the increase of the rib rigid; the same time, With respect to the arch rib torsional stiffness and vertical bending stiffness, lateral stiffness of the arch rib have greatest impact on the overall stability of the arch bridge.