基于概率分析的钢箱梁竖向温度梯度模式

Study on temperature gradient of steel box girder without pavement based on probability analysis

为了研究无桥面铺装时钢箱梁的温度场问题,根据热传导理论和有限元原理,采用ANSYS软件,对四川省泸州市沱江四桥主桥钢箱梁在施工过程中的温度场进行了计算。将计算温度与现场实测温度进行了比较,发现二者非常接近。计算结果表明:采用有限元方法计算钢箱梁温度场是可行的。以四川泸州沱江四桥主桥在顶推施工时的温度场监测数据为基础,采用指数函数,对钢箱梁在无桥面铺装时的竖向温度梯度进行了拟合。应用数理统计学方法,对顶、底板的竖向正温差进行了分析。分析结果表明:2个Weibull分布函数的加权和能够精确反映其竖向正温差的分布规律。采用极值分析的方法,得到了设计基准期内无桥面铺装的钢箱梁在竖向的正温差代表值。

In order to study temperature field of steel box girder without pavement,a three-dimensional model for a section of Sichuan Luzhou Tuojiang 4 th Bridge steel box girder without pavement was established during the construction using ANSYS.The temperature field was calculated according to principles of heat conduction.The calculated temperature field at the scene of Tuojiang 4 th Bridge was very close to the measured one.The temperature field of steel box girder calculated by the finite element method was possible.Based on the measured data of Tuojiang 4 th Bridge during construction,the formula of exponential function was adopted to simulate the vertical temperature gradient of the steel box girder without pavement in Sichuan.The statistical method was used in the analysis of the vertical positive temperature differences between the top plate and the bottom plate of the steel box girder without pavement.The positive temperature differences between the top plate and the bottom plate could be described by the weighted sum of two Weibull distributions.The representative value of vertical positive temperature differences in design reference period was further obtained by extreme value theory.