华南理工大学学报(自然科学版) ›› 2023, Vol. 51 ›› Issue (8): 21-31.doi: 10.12141/j.issn.1000-565X.220735

所属专题: 2023年交通运输工程

• 交通运输工程 • 上一篇    下一篇

温度荷载作用下植筋锚固纵连无砟轨道界面的性能演变

路宏遥1,2,3 许玉德1,2   

  1. 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.上海工程技术大学 城市轨道交通学院,上海 201620
  • 收稿日期:2022-11-09 出版日期:2023-08-25 发布日期:2023-03-16
  • 通信作者: 路宏遥(1990-),男,博士生,主要从事轨道结构健康监测技术研究。 E-mail:luhongyao1@163.com
  • 作者简介:路宏遥(1990-),男,博士生,主要从事轨道结构健康监测技术研究。
  • 基金资助:
    国家自然科学基金资助项目(51978393)

Evolution of Interface Performance of Longitudinal Ballastless Track Under Temperature Load After Embedded Steel Bars

LU Hongyao1,2,3 XU Yude1,2   

  1. 1.Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University, Shanghai 201804, China
    2.Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety, Tongji University, Shanghai 201804, China
    3.School of Urban Rail Transportation, Shanghai University of Engineering Science, Shanghai 201620, China
  • Received:2022-11-09 Online:2023-08-25 Published:2023-03-16
  • Contact: 路宏遥(1990-),男,博士生,主要从事轨道结构健康监测技术研究。 E-mail:luhongyao1@163.com
  • About author:路宏遥(1990-),男,博士生,主要从事轨道结构健康监测技术研究。
  • Supported by:
    the National Natural Science Foundation of China(51978393)

摘要:

为明确温度荷载作用下纵连板式无砟轨道植筋后层间界面的性能演变,结合现场轨道板温度场监测数据生成荷载谱,开展复合试件植筋前后界面力学与疲劳性能试验;基于试验结果建立了考虑界面损伤全过程的无砟轨道植筋空间精细化有限元模型,分析了不利温度荷载作用下层间界面的应力状态和损伤特征;引入界面损伤起始温度荷载的概念,计算了植筋锚固后层间界面出现损伤的起始温度荷载的变化情况,明确了黏结性能退化后界面出现脱黏风险时间的演变情况。结果表明:植筋后层间界面的承载能力显著提高,脱黏破坏的临界位移与荷载值分别提高了76.38%和153.41%,且表现出更好的疲劳性能,说明采用合理的植筋方式降低无砟轨道层间界面脱黏的风险是可行的。植筋锚固并未能够根本上限制温度力在无砟轨道结构内的传递,对板边界面位置处的损伤抑制作用有限,同时易导致植筋孔附近界面出现隐蔽性损伤,其最大损伤值可达0.944。随着服役年限增加,引起层间界面出现起始损伤的起始温度荷载不断降低,界面处于良好黏结状态的安全温度变化幅度由30.3 ℃下降至16.3 ℃,可能发生界面损伤风险的天数增加了64.29%,未进入极端天气时层间界面可能已出现损伤。工务部门需结合线路实际病害发展情况调整所关注的板温范围,动态调整维修阈值的设定标准。

关键词: 高速铁路, 无砟轨道, 温度荷载, 植筋锚固, 界面性能, 演变规律

Abstract:

In order to clarify the performance evolution of the interlayer interface of the longitudinal slab ballastless track under the temperature load, this study carried out the mechanical and fatigue performance tests of the interface after embedded steel bars of the composite specimen, and the load spectrum was generated by combining the temperature field monitoring data of the track slab on site.The spatial refined finite element model of ballastless track considering the whole process of interface damage was established and the stress state and damage characteristics of the interface between the lower layers under adverse temperature load were analyzed. The concept of initial temperature load of interface damage was introduced.The change in temperature load at the onset of damage at the interlayer interface after embedded steel bars was calculated and the evolution of debonding risk time after structural performance degradation was clarified. The results show that bearing capacity of the interlayer interface embedded with steel bar is significantly improved.The critical debonding failure displacement and the maximum load are increased by 76.38% and 153.41% respectively, and the fatigue performance is better, indicating that it is feasible to reduce the risk of interfacial debonding of ballastless track through embedding steel bars. The anchoring of embedded steel bars can not fundamentally limit the transmission of temperature force in the ballastless track and the damage suppression effect at the boundary of the slab is limited. It is easy to cause hidden damage near the reinforcement planting hole and the maximum damage value can reach 0.944. With the increase of service life,the initial temperature load that causes the initial damage of the interlayer interface decreases continuously. The safe temperature change range of good bonding state of the interface is reduced from 30.3 ℃ to 16.3 ℃.The number of days with possible interface damage risk is increased by 64.29% and the interlayer interface may have been damaged before extreme weather occurs.The railway department needs to adjust the temperature range of the concerned board based on the actual development of line diseases, and dynamically adjust the setting standards for maintenance thresholds.

Key words: high-speed railway, ballastless track, temperature load, embedded steel bars, interface performance, evolution law

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