自锚式钢箱梁悬索桥静力稳定性分析

Analysis on Static Stability of Self-Anchored Suspension Bridge with Steel Box Girder

为了解自锚式钢箱梁悬索桥的整体失稳模态和钢箱加劲梁的局部稳定性,以重庆鹅公岩轨道专用桥(主跨600m自锚式钢箱梁悬索桥)为背景,采用Abaqus软件建立全桥多尺度有限元模型(跨中段钢箱梁建立局部精细模型),采用弧长法进行非线性静力稳定承载力分析,研究该桥的整体稳定和局部稳定问题及其相互影响规律。结果表明:达到整体稳定极限荷载时,该桥跨中段钢箱梁发生明显的竖向和横向变形,全桥静力稳定极限状态由钢箱梁的整体稳定控制;整体稳定极限状态下,跨中段钢箱梁主要板件不会发生局部屈曲,中腹板局部发生屈服,其余板件仍处在弹性阶段,中腹板是钢箱梁局部稳定的控制部件。

In order to investigate the integral instability mode of the self-anchored suspension bridge with steel box girder and the local stability of the steel box stiffening girder, Chongqing Egongyan Rail Transit Special Use Bridge (a self-anchored suspension bridge with steel box girder and main span of 600 m) was taken as a research background. Moreover, a multi-scale finite element model was established by the Abaqus software, in which the steel box girder in a mid-span position was modeled in refined elements locally. Thereby, the nonlinear static stability analysis for the bridge was analyzed by using the arc-length method, and the integral stability, local stability and the interaction between these two stability phenomena of the bridge were investigated. Conclusions can be drawn as follows: when the ultimate load for integral stability is loaded, the vertical and transverse deformations in mid-pan position of the bridge occur obviously, and the ultimate state of static stability for the bridge can be controlled by the integral stability of the steel box girders;in a state of the ultimate stability, local buckling phenomena of the main panels in steel box girders of mid-span will not occur, and the middle web will be in a yield state but the other panels will be still in an elastic state, thus the middle web is the controlling part for the static local stability of steel box girders.