摘要
基于东南地区某高速铁路桥上曲线段CRTSⅡ型板式无砟轨道三年的实测温度数据,采用时间序列差分法将温度时程曲线趋势变化和短周期变化进行分解,得到轨道结构的均匀温度时程,并用傅里叶级数进行拟合,提出轨道结构均匀温度时程拟合表达式;考虑到常用的概率模型求取梯度极值忽略了尾部数据的影响,导致不同重现期梯度代表值计算存在一定误差,采用GPD数学模型对梯度尾部样本进行拟合与重现期估计,提出轨道结构现场实测最大温度梯度模式与对应100 a重现期的温度梯度拟合模式。研究表明:GPD模型可对尾部极值温度数据进行很好地拟合,预估不同概率需求的温度梯度作用值;轨道结构年均匀温度为21.38℃,年均温的变化幅值为11.3℃;采用GPD模型对轨道结构梯度100 a重现期代表值进行计算,截面Ⅱ顶底测点最大正温差的实测值与估计值分别为18.8、26.8℃,采用指数形式对结构竖向温度梯度实测最值与估计值进行拟合,拟合相关系数的平方均在0.98以上,可为无砟轨道结构温度作用取值提供参考。
Based on the three-year measured temperature field data of CRTSⅡslab ballastless track on the curve section of a high speed railway bridge in southeast China the changes of the trend and the short period about temperature time history curves were decomposed by means of time series difference method to obtain the uniform temperature time history of track structure.The fitting expressions of the uniform temperature of track structure were put forward by means of Fourier series.Considering that the conventional statistical model neglected the tail of samples during the calculation of the temperature gradient extremum,resulting in a certain error in the calculation of the gradient representative value of different return periods.The GPD model was used to fit the tail data of the track structure temperature gradient and the recurrence period estimate.The maximum temperature gradient model measured in situ on the track structure and the corresponding temperature gradient fitting model for 100-year return period were presented.The results reveal that the GPD model can well fit the extreme temperature data of tail,estimating the temperature gradient load value of different probability demands.The annual mean temperature of track structure is 21.38℃,with 11.3℃variation range of annual mean temperature.The estimated value of corresponding 100-year return period can be calculated by using GPD model.The measured and estimated values of the maximum positive temperature difference between the top and bottom measuring points of the sectionⅡare 18.8℃and 26.8℃respectively.The measured maximum values and the estimated values of the vertical gradient are fitted with exponential form.The correlation coefficients of the fitting forms are more than 0.98,which are used for temperature effect values on ballastless track structure.
作者
梁金宝
戴公连
唐宇
杨凌皓
LIANG Jinbao;DAI Gonglian;TANG Yu;Yang Linghao(School of Civil Engineering, Central South University, Changsha 410075, China;China Railway Siyuan Survey and Design Group Co., Ltd., Wuhan 430063, China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2021年第1期122-127,共6页
Journal of the China Railway Society
基金
国家自然科学基金(51378503)
中国铁路总公司科技研究开发计划(2015G001-K)。
关键词
高速铁路
无砟轨道
均匀温度
GPD模型
温度梯度
high-speed railway
ballastless track
uniform temperature
GPD model
temperature gradient
