纵连板式无砟轨道动态应变分布规律研究  

Study on Dynamic Strain Distribution of Longitudinally Connected Ballastless Slab Track

作　　者：胡颖[1,2] 肖杰灵 陈醉[1,2] 陈流宇 杨荣山[1,2] 刘学毅 HU Ying;XIAO Jieling;CHEN Zui;CHEN Liuyu;YANG Rongshan;LIU Xueyi(MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China;School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]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 [2]西南交通大学土木工程学院,成都610031

出　　处：《铁道标准设计》2022年第6期27-32,共6页Railway Standard Design

基　　金：国家自然科学基金项目(51778543,51978584)。

摘　　要：纵连板等无砟轨道的疲劳损伤与列车动载作用密切相关,特别是动荷载作用时,将在作用点附近形成较高的应变率及梯度分布,是造成无砟道床动力损伤不可忽视的因素。为研究纵连板在高速列车荷载作用下的应变分布规律,基于车-轨耦合作用动力学理论及模型,研究轨道结构混凝土应变速率演变规律及影响因素。结果表明:轨道结构应变率随窄接缝尺寸和砂浆层弹性模量增大而减小;轨道结构沿垂向应变率变化较纵、横向更为敏感;轨道板等结构受拉区应变率远大于受压区;列车荷载作用下砂浆层应变率最大值为2.193×10^(-3)/s,窄接缝位置处应变率最大值达到1.096×10^(-3)/s,二者均明显大于轨道结构其余部分,建议进行纵连式轨道动力研究时宜着重关注窄接缝和砂浆层的动态应变变化。The fatigue damage of longitudinally connected ballastless slab track is closely related to the dynamic load of train. Especially, when the dynamic load is applied, a higher strain rate and gradient distribution will be formed near the action point, which is an important factor causing the dynamic damage of ballastless track bed. In order to study the strain distribution of longitudinally connected ballastless slab track under high-speed train load, the strain rate evolution law and influencing factors of the concrete of track structure are studied based on the dynamic theory and model of vehicle rail coupling. The results show that: with the increase of the narrow joint size and the elastic modulus of mortar layer, the strain rate of track structure decreases;the strain rate of track structure along the depth direction is more sensitive than that of longitudinal and transverse;the strain rate of the lower tensile part of track slab structure is far higher than that of the upper part;the maximum strain rate of mortar layer under the train load is 2.193×10^(-3)/s and the narrow joint reaches 1.096×10^(-3)/s, and both of them are significantly higher than that of the rest of the track structure. It is suggested that more attention should be paid to the dynamic changes of the narrow joint and mortar layer in dynamic study of longitudinally connected track.

关 键 词：高速铁路 无砟轨道 纵连板式轨道 车轨耦合 动力学 应变率 

分 类 号：U213.244[交通运输工程—道路与铁道工程]