弧长比例对曲线斜拉桥力学性能影响分析

Influence of Arc Length Ratio on Mechanical Properties of Curved Cable-stayed Bridge

曲线斜拉桥是主梁呈曲线的斜拉桥。其兼具弯梁桥和斜拉桥的受力特点,主梁在承受弯矩、剪力作用的同时承受了较大的扭矩作用,受力复杂,具有高度空间性。以某座主跨285 m混凝土Π形主梁双塔双索面曲线斜拉桥为工程背景,基于有限元分析方法,通过改变曲线斜拉桥弧长比例(曲线斜拉桥曲线部分长度占全桥长度的比例,取值为[0,1])以探究弧长比例变化对结构受力性能的影响规律,主要研究对象包括主梁应力、内力、挠度以及支座反力等。研究结果表明:弧长比例对主梁轴力、剪力影响较小,相对于直线斜拉桥,变化不大于5%,可按直线桥进行计算;弧长比例在不同区间变化对主梁弯矩和扭矩的影响呈现不同趋势。研究成果针对弧长比例这一参数对曲线斜拉桥提供设计建议,为道路选线及桥梁设计提供参考依据。

Curved cable-stayed bridge is a cable-stayed bridge with curved main beam.It has stress features of both curved beam bridge and cable-stayed bridge.The main beam,under the action of bending moment and shear force,bears a larger torque.This type of bridge is under extremely complexforce with a high degree of space.With reference to arc length of the curve cable-stayed bridge(the ratio of the curve length of the curve-stayed bridge to the length of the whole bridge,the value is[0,1]).The main research objects include main beam stress,internal force,deflection and bearing reaction.The research results show that the arc length ratio has little effect on the axial force and shear force of the main beam,and its change is not more than 5%compared with the straight cable-stayed bridge.The arc length ratio can be calculated as that of the straight bridge.The influence of the arc length ratio on the bending moment and torque of the main girder varies with different intervals.The research results provide design suggestion for curve cable-stayed bridge in terns of the arc length ratio,which may serve for route selection and bridge design.