成桥混凝土箱梁温度场观测与温差分布研究

Observation and research on temperature field and temperature difference distribution in concrete box girders of finished-state-bridge

以广东佛山市潭州大桥扩建桥为工程实例,对该成桥箱梁的温度场及其挠度进行了现场观测;分析了其各板块全天温度变化的特点及趋势,重点研究了箱梁截面的竖向温度分布规律,并采用非线性回归方法给出了箱梁截面竖向温差分布模式,在此基础上,分别按该温差分布模式、公路规范温差分布模式以及其他文献温差分布模式,采用有限元软件MIDAS/CIVIL对该桥进行了温度变形仿真分析。研究结果表明,箱梁内温度变化比环境温度变化滞后约2～3h,基于不同的温差分布模式计算得到的箱梁挠度效应相差较大,按本文温差分布模式计算的挠度与实测值吻合较好。

Taking the Tanzhou expansion bridge as an engineering example, the temperature field and deflection of the box beam of this finished-state-bridge was observed on site.This paper analyses the characteristics and trends of temperature change of each plate all day long, mainly studies the vertical temperature distribution rule of the box beam, and puts forward the vertical temperature difference distribution pattern of the concrete box girder section of this bridge by using nonlinear regression method.On this basis,according to the temperature difference distribution pattern obtained above,the temperature difference distribution patterns given in highway standard and other literatures separately,the temperature-deformation of the bridge was simulated and analyzed by using the finite element software MIDAS/CIVIL.The results show that the temperature change inside the box beam lags about 2~3h than the ambient , and the deflection-effects of the box beam based on different temperature difference distribution patterns has obvious difference,and the deflection are in good agreement with the measured ones in use of the temperature difference distribution pattern proposed in this paper.