大跨中承式钢管混凝土拱桥极限承载能力

分析了大跨中承式钢管混凝土拱桥在设计荷载工况作用下的静力失稳全过程,对其受力特性及破坏机理进行了探讨,并对桥面系非保向力作用对结构稳定性的贡献进行了讨论。结合ANSYS软件的分析功能,对一360 m跨的中承式钢管混凝土拱桥进行了荷载工况-恒载+全跨双向汽车荷载+全跨双向人群荷载+风荷载-作用下的极限承载能力分析,通过内力、变形等指标描述了算例的静力失稳全过程。分析结果表明,结构达极限荷载时发生的面外失稳破坏属于典型的极值点失稳问题,在此过程中,桥面系对拱肋的非保向力作用对结构面内、外刚度均有贡献,且在拱肋弹性受力阶段贡献更大。

Analysis on ultimate load-bearing capacity of large-span half-through CFST arch bridge

The whole buckling procedure of large-span half-through CFST(Concrete filled steel tubular) arch bridge under design load case was analyzed in order to understand structural behavior and failure mechanism.During the analysis,the function of non-conservative force from deck system was discussed.The ANSYS program was used to analyze as example,ultimate load-bearing capacity of a 360 m half-through CFST arch bridge.The whole static buckling procedure was demonstrated with internal forces and displacements resulted from load combination of dead load,vehicle load,pedestrian load and wind load.It is concluded that the out-of-plane buckling of large-span half-through CFST arch bridge belongs to typical ultimate-point failure problem.It is shown that the non-conservative force from deck system applied to arch ribs has the contribution to both in-plane and out-of-plane stiffness,especially at elastic state.