钢管混凝土拱桥拱肋接缝错台问题研究

Research of Arch Rib Joint Deviation for Concrete Filled Steel Tubular Arch Bridge

选取拱肋截面为单圆管、哑铃形、桁式的钢管混凝土拱桥各一座,建立有限元模型,分析了钢管拱肋接缝错台对成桥状态下受力性能和截面承载力的影响。研究结果表明:接缝错台对拱肋轴力、竖向变形几乎没有影响,而对拱肋截面弯矩影响较小;错台幅值的增大,会造成钢管混凝土截面承载力逐渐降低,承载力的下降幅度与错台值、钢管面积的变化率基本呈线性相关的关系。在目前规范规定的错台限值情况下,截面弯矩最大变化率不超过1.2%;截面承载力下降幅度不超过4%;目前桥梁施工规范中对接缝错台的限定较为合理。

Three types of CFST arch bridge with rib cross-sections of single tube, dumbbell and truss were selected to build FEM models. The effect of arch rib joint deviation on mechanical behavior and section carrying capacity under condition of completion were analysed. The research result shows that （1） the joint deviation has little influence on axial force and vertical deformation, and has less influence on section moment of arch rib; （2） section carrying capacity of CFST will reduce with increment of joint deviation; （3） There are linear dependence relation of deviation stipulated in the current bridge construction specification, the maximal change rate of section moment and reduce rate of carrying capacity are no more than 1.2% and 4% respectively. The limit of joint deviation in the current bridge construction specification is rational.