CRTSⅡ型板式无砟轨道结构层间界面损伤演化研究  

Study on Interface Damage Evolution between Layers of CRTSⅡSlab Ballastless Track Structure

作　　者：王军 卢朝辉[3] 张玄一 WANG Jun;LU Zhaohui;ZHANG Xuanyi(Key Laboratory of Road and Traffic Engineering of the Ministry of Education,Tongji University,Shanghai 201804,China;Key Laboratory of Structural Durability and System Safety of Shanghai Rail Transit,Tongji University,Shanghai 201804,China;Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]同济大学道路与交通工程教育部重点实验室,上海201804 [2]同济大学上海市轨道交通结构耐久与系统安全重点实验室,上海201804 [3]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124

出　　处：《铁道学报》2024年第11期112-124,共13页Journal of the China Railway Society

基　　金：国家自然科学基金(51820105014,52108104)。

摘　　要：为更准确模拟CRTSⅡ型轨道板与CA砂浆层间界面损伤行为,基于简化指数型内聚力模型表征界面非线性拉力-位移关系,推导混合模式下指数型内聚力模型表达式,并通过相关试验数据验证模型的正确性。基于提出的混合模式指数型内聚力模型,建立考虑层间和板间损伤的CRTSⅡ型板式无砟轨道有限元模型。考虑窄接缝完全损伤病害,分析层间离缝长度、整体温升和正温度梯度对CRTSⅡ型板式无砟轨道结构上拱变形、接缝应力和界面损伤的影响规律。研究结果表明:提出的混合模式指数型内聚力模型可以准确模拟界面Ⅰ型、Ⅱ型和Ⅰ+Ⅱ混合型断裂行为;窄接缝完全损伤后,在正温度作用下轨道板间接缝处的上拱变形最大,且界面损伤以接缝为中心向两边扩展并逐渐减小;接缝压应力随整体温升和正温度梯度的增加线性增大;当离缝长度为10个扣件间距,在整体温升40℃作用下界面会产生开裂;考虑夏季高温天气,为防止轨道板上拱变形过大,层间离缝长度应控制在5个扣件间距以内。To more accurately simulate the interface damage behavior between CRTSⅡtrack slab and CA mortar layer,an expression of exponential cohesive zone model under the mixed mode was derived,which was developed from the simplified exponential cohesive zone model for characterizing the nonlinear traction-separation relationship at the interface.The validity of the model was verified by relevant experimental data.Based on the proposed mixed-mode exponential cohesive zone model,a finite element model of CRTSⅡslab ballastless track structure considering interlayer and inter-slab damage was established.Considering the complete damage of narrow joints,the effects of interlayer gap length,overall temperature rise and positive temperature gradient on the structural arching deformation,the joint stress and interface damage of CRTSⅡslab ballastless track were analyzed.The results showed that the proposed mixed-mode exponential cohesive zone model can accurately simulate modeⅠ,modeⅡand mixed-modeⅠ+Ⅱfracture behaviors.In the case of complete damage of the narrow joint,the joint arching deformation between track slabs was the largest under the action of positive temperature,with the interface damage expanding from the joint center to both sides and gradually decreasing.The joint compressive stress increases linearly with the increase of overall temperature and positive temperature gradient.When the gap length was 10 fastener spacings,cracking will occur at the interface under the action of overall temperature rise of 40℃.Considering the high temperature weather in summer,the gap length should be controlled within 5 fastener spacings to prevent excessive arching deformation of the track slab.

关 键 词：CRTSⅡ型板式无砟轨道结构 层间离缝 混合模式指数型内聚力模型 窄接缝损伤 上拱变形 

分 类 号：U213.244[交通运输工程—道路与铁道工程]