组合荷载作用下CRTSⅢ型板式无砟轨道层间离缝影响分析  

Study on the influence of connection damage for CRTS Ⅲ slab ballastless track under combined loads

作　　者：娄平[1,2] 赵晨 宫凯伦 LOU Ping;ZHAO Chen;GONG Kailun(School of Civil Engineering,Central South University,Changsha 410075,China;Key Laboratory of Heavy Railway Engineering Structure of Education Ministry,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]重载铁路工程结构教育部重点实验室,湖南长沙410075

出　　处：《铁道科学与工程学报》2019年第12期2913-2920,共8页Journal of Railway Science and Engineering

基　　金：国家重点研发计划项目(2017YFB1201204);国家自然科学基金资助项目(51578552,U1334203)

摘　　要：在车辆荷载和温度作用下,CRTSⅢ型板式无砟轨道由于自密实混凝土层与底座板间产生离缝,发生应力集中和局部变形,对无砟轨道服役状态和使用寿命造成明显影响。基于ABAQUS有限元模型,计算车辆与温度不同荷载组合下,层间离缝横向和纵向发展对无砟轨道结构受力变形的影响,探究伤损演变规律和维修限值。研究结果表明:层间离缝宽度小于1.5m,轨道结构受力和变形的影响很小;离缝发展至两侧钢轨正下方后,轨道结构变形和应力均增大明显;离缝长度大于1.2m,对轨道板出现受拉裂缝和无离缝端上翘;正温度梯度荷载对轨道板弯折变形和自密实混凝土层纵横拉应力以及负温度梯度荷载对轨道板上翘和纵横拉应力均有叠加放大效应。Under the action of vehicle load and temperature, the crack between self-compacting concrete layer and base plate of CRTS Ⅲ slab ballastless track causes stress concentration and local deformation, which has a significant impact on the service state and service life of ballastless track. Based on ABAQUS finite element model, this paper calculated the effect of lateral and longitudinal development of interlayer joints on the stress and deformation of ballastless track structure under different load combinations of vehicle and temperature, and explored the damage evolution law and maintenance limits. The results show that the stress and deformation of track structure are little affected when the width of interlayer separation joint is less than 1.5 m;the deformation and stress of track structure increase rapidly when the separation joint develops directly below the rails on both sides;when the length of separation joint is more than 1.2 m, the track slab appears tension cracks and warping at the seamless end;the bending deformation of track slab and the longitudinal and transverse tension stress of self-compacting concrete layer are affected by positive temperature gradient load;and negative temperature gradient loads have superimposed magnification effects on the warping and longitudinal and transverse tension stresses of track slabs.

关 键 词：CRTSⅢ型板式无砟轨道 层间离缝 力学特性 温度作用 

分 类 号：U213.2^+44[交通运输工程—道路与铁道工程] U238