我国典型地区无砟轨道非线性温度梯度及温度荷载模式  

Vertical Nonlinear Temperature Distribution and Temperature Mode of Unballasted Track in Typical Areas of China

作　　者：闫斌[1,2] 刘施[1] 戴公连[1,2] 蒲浩[1,2] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学高速铁路建造技术国家工程实验室,湖南长沙410075

出　　处：《铁道学报》2016年第8期81-86,共6页Journal of the China Railway Society

基　　金：国家自然科学基金(U1334203);中国铁路总公司科技研究开发计划(2014G001-D)

摘　　要：与外界环境的热交换过程中,无砟轨道结构内部温度呈非线性分布,其竖向温度梯度不仅影响连续轨道结构的稳定性,还引起轨道板反复翘曲变形导致砂浆层离缝。本文基于有限元软件ANSYS,考虑轨道所处经纬度、局部气候的影响,将热交换作用转化为热流密度边界条件施加于无砟轨道温度场热力学分析模型,研究无砟轨道竖向非线性温度分布规律,并通过实测数据验证该分析方法的准确性。在此基础上,研究不同地理坐标和气候条件下无砟轨道竖向温度梯度的地区分布规律,通过加入地区调整系数,提出适用于我国典型地区的无砟轨道竖向温度荷载模式。研究表明：无砟轨道表面温度随环境温度变化剧烈,其内部温度变化在时间上存在一定滞后,变化幅度随深度的增加迅速减弱;我国各地无砟轨道最大正温度梯度出现在5~8月的13：30~16：00,最大竖向正温差平均为17.0℃,最大负温度梯度出现在1月的5：00~5：30,最大负温差平均为8.7℃。During the heat exchange with external environment, there is a vertical nonlinear temperature gradient in unballasted track structure. The vertical temperature gradient not only affects the stability of continuous track structure, but also causes warpage of track plate, resulting in debonding of mortar layer from the joint. Based on the finite element software ANSYS, considering the influence of the latitude and longitude of the track and local climate, the heat exchange effects were transformed into heat flux boundary conditions and applied to the thermodynamic analysis model of unballasted track temperature field. In addition, the accuracy of the calculation method was validated by the measured data. On this basis, the vertical temperature gradient distribution of unballasted track under different geographical coordinates and climatic conditions was studied and the vertical temperature load mode for unballasted track applicable to typical regions in China was explored, through addition of the regional adjustment coefficients. Studies have shown that unballasted track surface temperature changed greatly with the environmental temperature while its internal temperature change showed a certain time lag and the amplitude of variation weakened fast with increase of the depth. The maximum positive temperature gradient of unballasted track throughout the country occurs at 13： 30- 16： 00 from May to August, with maximum vertical average positive temperature difference of unballasted track being 17. 0℃,while the maximum negative temperature gradient occurs at 5 ： 00- 5： 30 in January, with average negative temperature difference being 8. 7 ℃.

关 键 词：轨道工程 无砟轨道 热力学分析 温度梯度 分布规律 

分 类 号：U213.2[交通运输工程—道路与铁道工程]