Static Wind-Induced Lateral Stability Analysis Of Long Span Concrete Filled Steel Tubulrear Arches Bridge

In urban and highway bridges, the CFST arch bridge is the bridge construction style with large amount, strong competition, long history, activity and ever development because of its large span, high capacity, low cost and maintenance fees, grand figuration and etc. As a compress-bend structure, with increasing of the span, length slender ratio and carrying load of arch increase, lateral rigidity and width span ratio of arch ring minish relatively. During construction and service stages, lateral stability becomes more important and a control factor of arch bridge design. So lateral ultimate loading capacity of CFST arch bridges is becoming a more and more serious problem.Based on the summary of current researches on circularity and parabola arch at home and abroad, taking the long-span catenary arch bridge without cross-beam as the object of study, a practical method for the lateral stability calculation of ribbed arches with catenary rib curve is established. Lateral ultimate loading capacity of long span catenary arch bridge(deck bridge, half-through bridge, through bridge) was analyzed systemly.1. Catenary single rib arch that carries vertical loadings and transverse wind loadings was analyzed in this paper, calculation formula of critical loading of lateral stability flexuosity by the energy principle. The structure parameter influences on lateral stability, such as crankle rigidity ratio of arch rib, arch axis coefficient, arch high span ratio, lateral rigidity of bridge decking and arch rib ratio, the effect of non-orientedly conservative loadings of bridge deck, lateral wind loadings were discussed. Corresponding numerical charts were given, and they may be of some reference value and helpful to the parameter design of ribbed arches.2. In this paper, the example bridge is a long-span half-through CFST arch bridge of a 100m span in Yi Lan. Two loading sequences are used to determine the load-deformation response and the ultimate load of the bridge: Sequence I is the sequence in which the dead and wind loads are applied first and then the live load is increased proportionally to the collapsed load ; Sequence II is the sequence in which the dead and live loads are applied first and then the wind load(wind velocity) is increased proportionally to the collapsed load(critical wind velocity). The ultimate capacity of this bridge under two loading sequences is investigated using geometrically and materially nonlinear buckling method. The effects of long-span CFST arch bridges are discussed.