桥上CRTSⅡ型板式轨道结构竖向温度场预估模型

The prediction model of vertical temperature field for CRTSⅡ slab track on bridge

将桥上CRTSⅡ型板式无砟轨道结构视为多层层状体系,基于传热学基本原理,考虑模型边界条件,建立轨道结构温度场分析模型,以日照时长、日辐射总量、日平均气温和日温差为自变量,回归分析提出轨道结构竖向温度分布预估模型,研究桥上CRTSⅡ型板式无砟轨道结构的竖向温度场分布。研究结果表明:利用理论模型计算得到的轨道结构温度场分布与实测结果对比具有较好一致性;将各环境因素视为独立变量,轨道结构表面温度最值、轨道板温差随日照时长、日辐射总量、日平均气温、日温差成线性变化,轨道结构内部温度在当表面温度取最值时随深度成3次曲线线形变化;根据预估模型所得的轨道板表面温度最值、轨道板温差、轨道结构竖向温度预估值与实测值、理论值误差小于2%;利用温度场预估模型可根据气象数据快速计算得到轨道结构竖向温度分布,可为精确计算轨道结构温度效应提供参考。

In this paper,a temperature field analysis model for CRTSⅡslab track on bridge was established based on the heat transfer theory,in which the CRTSⅡslab track on bridge was modeled as a multilayer system and the boundary condition of the model was considered.A prediction model of slab surface extreme temperature value,temperature difference and the structure inside temperature variation is put forward taking the length of sunshine time,daily radiation,daily average temperature,daily temperature difference as independent variables.The vertical temperature field distribution of CRTSⅡslab track on bridge was analyzed.The results show that the temperature field distributions of the track calculated by theoretical model are good agreement with those by the experimental results;when the environmental factors change independently,the temperature extreme value and temperature difference of slab linearly change with the length of sunshine time,daily radiation,daily average temperature,daily temperature difference,and the temperature of the track inside change with the depth as cubic curve when the slab surface temperature takes the extreme value;Comparing with the experiment results,theory calculation results as well as the predicting results of the slab surface extreme temperature value,temperature difference and the structure inside temperature variation,the errors are less than2%;the prediction model can be used to calculate the vertical temperature field distribution of the track based on the meteorological data,and is helpful to calculate the track temperature effect conveniently and accurately.