大跨度混凝土斜拉桥温度效应的研究与分析

斜拉桥为高次超静定结构,在施工过程中,其索力和主梁标高都会受到温度的影响。为了研究大跨度混凝土斜拉桥的温度效应问题,在贵州红枫湖特大桥施工过程中进行了14h温度效应的观测。得出了该桥主梁浇筑阶段和主梁合龙后温度场对索力和主梁标高的影响曲线,在实测资料的基础上,对索梁温差、桥面日照、桥塔日照三种影响因素进行线性拟合,运用有限元的方法进行了理论计算,通过与实测资料的比较,说明温度效应的影响可根据理论计算结果进行修正。并对主梁立模标高和斜拉索的张拉索力的主动修正问题进行了分析和讨论。

Analysis and Research of Temperature Effects on Long-span Concrete Cable-stayed Bridge

Cable-stayed bridge is a kind of high degree statically indeterminate structure.Its cable force and elevation of main beam can be affected by temperature under construction.In order to study the problem of temperature effects on long-span concrete cable-stayed bridge,temperature effects have been measured for fourteen hours during the construction of Hongfenghu Super Major Bridge.The influence charts of temperature effects on cable force and elevation of main beam in construction and completion have been gained.Based on the actually-measured data,linear fitting has been done on the three following affecting factors as difference in temperature of cable and beam,solar temperature of deck,solar temperature of pylon tower.Theoretical calculation has been carried on with finite-element method.Through the comparison between calculated results and the measured data,it has been shown that the influence of temperature effect on the bridge can be corrected according to the calculated results.Furthermore,the analysis and discussion have been done on the problem of making an active correction to the formwork erection elevation of the main beam and cable force.