铁道科学与工程学报2024，Vol.21Issue(6)：2359-2370,12.DOI:10.19713/j.cnki.43-1423/u.T20231293
磁悬浮轨道梁均匀温度及温差分量极值研究
Study on extreme values of uniform temperature and temperature difference components in maglev track beams
摘要
Abstract
Unlike conventional road and railway bridges,the temperature field of maglev track beams is affected by the surrounding magnetic field and the heating of functional components.Given the current absence of explicit regulations in Chinese standards regarding extreme values for the uniform temperature and temperature difference component of maglev track beams,studying representative values for temperature components with probabilistic assurance holds significant importance.Based on the on-site temperature monitoring data collected over one year for a concrete box girder of the Changsha maglev operational line,this study analyzed the time-varying characteristics of the uniform temperature component and vertical equivalent linear temperature difference component of the girder.The Univariate linear regression(ULR)and Gradient Boosting Regression Tree(GBRT)methods were separately used to establish predictive models for the temperature components based on meteorological factors.Comparisons showed that the GBRT method not only improved the prediction accuracy of the uniform temperature but also overcame the limitation of ULR in predicting the vertical equivalent linear temperature difference.Subsequently,the long-term meteorological data from 1960 to 2019 were input into the established GBRT predictive models,obtaining the 60-year long-term forecast values for temperature components of the maglev box girder.After organization,Samples of daily extreme values and annual extreme values of the uniform temperature and vertical equivalent linear temperature difference were obtained.Combining the Maximum entropy extreme value model with the Fourier function,the time-varying curves of daily extreme values for each temperature component were derived.The Maximum entropy extreme value models were established for the annual extreme value samples,determining representative values for temperature components under a hundred-year return period.The research findings are as follows:the uniform temperature of the maglev box girder exhibits seasonal variations with a yearly cycle,while the vertical equivalent linear temperature difference is affected by solar radiation,showing higher values in summer and lower values in winter.The representative values for the uniform temperature and vertical equivalent linear temperature difference of the maglev box girder under a hundred-year return period are 44.4℃and 8.6℃,respectively.This method combines the GBRT algorithm with the maximum entropy extreme value model,addressing the issue of insufficient annual extreme value samples in extreme value analysis.The results can provide a reference for the temperature deformation design of maglev track beams.关键词
磁悬浮轨道梁/现场试验/均匀温度/等效线性温差/GBRT算法/最大熵模型/极值分析Key words
maglev track beam/field test/uniform temperature/equivalent linear temperature difference/GBRT algorithm/maximum entropy/extreme value analysis分类
交通工程引用本文复制引用
戴公连,罗泽江,王芬,何昌林,张昂..磁悬浮轨道梁均匀温度及温差分量极值研究[J].铁道科学与工程学报,2024,21(6):2359-2370,12.基金项目
国家自然科学基金资助项目(51708560) （51708560）
中国铁路总公司科技研究开发计划重点课题(2017G006-N) （2017G006-N）
湖南省自然科学基金资助项目(2018JJ3672) （2018JJ3672）
