斜拉桥索梁锚固区应力分析

Stress Analysis of Cable-beam Anchorage Zone of Cable-stayed Bridge

依据某矮塔斜拉桥,对索梁锚固区主梁受力进行现场试验,明确整个施工过程中的应力变化规律。通过采用弹性边界条件的索梁锚固区精细化分析模型,将计算结果与实测结果进行对比,验证了分析模型的准确性。同时,对索梁锚固区的主梁进行参数分析,研究索梁锚固区主梁在不同状态下的应力分布规律。结果表明:(1)在整个施工过程中,主梁索梁锚固区不同测点的应力在拉索张拉和下一根拉索安装前的应力变化较大,之后趋于稳定,翼缘板上部位置出现了拉应力。(2)收缩徐变、整体升温和整体降温对主梁混凝土压应力的影响较小。(3)温度变化对翼缘板锚固区混凝土的拉应力影响较大,桥梁设计时应充分考虑温度变化对索梁锚固区主梁翼缘板混凝土横向应力的影响。

Based on a short-pylon cable-stayed bridge,the stress of the main beam in the anchorage zone of cable beam is tested in the field to determine the variation rule of the stress in the whole construction process.A refined analysis model of cable beam anchorage zone with elastic boundary conditions is used to compare the calculation result and the measured result in order to verify the accuracy of the analysis model.At the same time,the parameters of the main beam in the anchorage zone of cable beam are analyzed to study the stress distribution law of the main beam in different states in the anchorage zone.The results show that during the whole construction process,the stress at different measuring points in the anchorage area of the main beam cable beam varies greatly before the tension of the cable and installation of the next cable,and then tends to be stable.The tension stress appears at the upper part of the flange plate.The shrinkage and creep,overall warming and overall cooling have little influence on the compressive stress of main beam concrete.The temperature change has a great influence on the tensile stress of concrete in the anchorage zone of flange plate.The influence of temperature change on the transverse stress of flanged slab concrete in the anchorage zone of cable beam should be fully considered in bridge design.