极端日气温差对单元道床板伸缩变形的影响分析  

Influence Analysis of Extreme Daily Air Temperature Difference on the Telescopic Deformation of Unit Bed Slab

作　　者：韦有信 杨斌 黄诚 赵振航 WEI You-xin;YANG Bin;HUANG Cheng;ZHAO Zhen-hang(School of Architectural Engineering, Nanjing Institute of Technology, Nanjing 211167, China;Engineering Management Center, China Railway Corporation, Beijing 100844, China;MOE Key Laboratory of High-speed Railway Engineering, Southwest Jiaotong University, Chengdu 610031, China)

机构地区：[1]南京工程学院建筑工程学院,南京211167 [2]中国铁路总公司工程管理中心,北京100844 [3]西南交通大学高速铁路线路工程教育部重点实验室,成都610031

出　　处：《铁道标准设计》2019年第7期41-46,共6页Railway Standard Design

基　　金：国家自然科学基金(51808283);江苏省高校自然科学基金(18KJB580007);南京工程学院引进人才科研启动基金资助项目(YKJ201428)

摘　　要：严寒地区双块式无砟轨道大单元道床板的日伸缩位移幅值与日气温均值存在阶梯型跳跃式的非线性关系,且跳跃时间点对应的日伸缩变化幅值显著放大。为掌握大单元道床板特殊的伸缩变形规律,明确其力学机理,通过对试验数据的统计分析和力学模型的理论推算,得出如下主要结论:严寒地区大单元道床板特殊的伸缩变形行为与极端日气温差的存在密切相关;极端日气温差20℃引起的板端日伸缩变形幅值可达到常见日气温差5~10℃的3.2~10.0倍;大单元道床板日伸缩变化幅值的放大效应与其温度梯度日变化幅值成正比,与其整体温度日变化幅值成反比;极端日气温差引起的极大温度梯度消失时对应的道床板整体温度值存在一定的随机性,由此引发道床板日伸缩位移均值的阶梯型跳跃式发展行为。The daily average telescopic displacement of double-block ballastless track’s large unit bed slab has a step-type and jumping nonlinear relationship with the mean value of the daily air temperature in the severe cold area, and the amplitude of the daily telescopic change corresponding to the jump time point shows a significant amplification. In order to grasp the special telescopic deformation law of the large unit bed slab and its mechanical mechanism, this paper conducts statistical analysis of the experimental data and theoretical calculation of the mechanical models. The main conclusions are as follows: the large unit bed slab’s telescopic deformation in severe cold regions is closely related to the existence of the extreme daily air temperature difference;the daily telescopic deformation amplitude caused by the extreme daily air temperature difference of 20 ℃ can reach 3.2~10.0 times of the common daily air temperature difference of 5~10 ℃;the daily telescopic deformation amplification effect of the large unit bed slab is proportional to the daily variation amplitude of its temperature gradient, and inversely proportional to the daily variation amplitude of its overall temperature;the corresponding overall temperature parameters of the bed slab has a certain randomness in the wake of the disappearance of the extreme temperature gradient caused by the extreme daily temperature difference, which results in the step-type and jumping development behavior of the unit bed slab’s mean telescopic displacement.

关 键 词：双块式无砟轨道 道床板 严寒地区 昼夜温差 伸缩变形 

分 类 号：U213.21[交通运输工程—道路与铁道工程]