用于结构状态判别的PC斜拉桥温度效应

温度效应对PC斜拉桥的结构状态判别至关重要。以天津永和大桥的维修为工程背景，分析了PC斜拉桥的温度效应，包括体系温差、索梁温差、主梁温度梯度、索塔温度梯度等对桥面线形、塔顶偏位、索力的影响。根据永和大桥前后2次维修的实测数据，验证了基于现行规范的PC斜拉桥温度效应分析方法的有效性，给出了结构状态判别中温度效应修正的方法和步骤。结果表明，体系温差和索塔温度梯度对塔顶偏位的影响较大，而索梁温差是影响主梁竖向变位的主要因素。尽管运营多年的旧桥结构的刚度退化可能会导致计算结果与相应的实测值出现一定的误差，但将基于现行规范的温度效应计算结果用于既有PC斜拉桥的结构状态判别基本上是可行的，可供同类型桥梁维修设计及施工控制参考。

Temperature Effect Analysis for structural state Estimation of PC Cable-stayed Bridge

The temperature effect was of crucial importance to estimate structural state of existing PC cablestayed bridges. Taking Yonghe Bridge in Tianjin as a case, the influence of temperature effect, including temperature change of whole bridge, difference in temperature of cable and main girder, temperature Gradient in the transverse section of main girder, and temperature gradient in the transverse section of tower, was analyzed on geometry of bridge deck, inclined displacement at the top of tower and cable force. Based on observation data of Yonghe Bridge during the First and Second maintenance, effectiveness of temperature effect analysis based on the present bride code in China was verified. And then a modifying method of temperature effect in structural state estimation was proposed. It was shown that the temperature change of whole bridge and the difference in temperature of cable and main girder were the main factors to inclined displacement at the top of tower, and the difference in temperature of cable and main girder was the main factor to the deflection of main girder. Although a small error between measured and theoretical results caused by the rigidity deterioration of old bridge, the temperature effect analysis based on the present bride code in China could be feasible in structural state estimation of existing PC cablestayed bridges and provided reference for maintenance and construction control.