大跨度斜拉桥钢-混结合段局部受力预测方法

On the method for predicting local forces in the steel concrete composite section of long span cable-stayed bridges

为避免斜拉桥出现应力过于集中而导致事故的发生,提出大跨度斜拉桥钢-混结合段局部受力预测方法。根据不同结构的钢-混结合段构造方式与特点,确定传力模式和传力路径,明确各部件的受压状态;通过建立有限元分析模型,探究混凝土、钢箱梁和剪力钉的材料特征,在不同工况下的效应组合作为有限元的分析依据,选择钢板与混凝土的合适单元类型设置边界条件,经过模型修正后确保预测结果更加精准。经过试验结果表明,所提方法的预测结果与实际计算结果相符,混凝土横桥应力的预测最大仅为0.7 MPa,钢板的受力预测最大误差为4.3 MPa,能够准确反映结合段的应力分布规律。

In order to avoid accidents caused by excessive stress concentration in cable-stayed bridges,the article proposes a local stress prediction method for the steel-concrete composite section of large-span cable-stayed bridges.Determine the force transmission mode and path based on the construction methods and characteristics of steel concrete composite sections of different structures,and clarify the compression state of each component;by establishing a finite element analysis model,exploring the material characteristics of concrete,steel beam boxes,and shear nails,and using the combination of effects under different working conditions as the basis for finite element analysis,appropriate element types of steel plates and concrete are selected to set boundary conditions.After model correction,the predicted results are ensured to be more accurate.The experimental results show that the predicted results of the proposed method are consistent with the actual calculation results.The maximum predicted stress of the concrete transverse bridge is only 0.7 MPa,and the maximum predicted error of the steel plate’s stress is 4.3 MPa,which can accurately reflect the stress distribution law of the bonding section.