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Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly
2025 Vol.26 No.8 P.738-754
Thermal-induced upwarp buckling analysis of CRTS II slab ballastless tracks experiencing joint damage
Abstract: When subjected to sustained high temperatures, the structure of the continuous China railway track system (CRTS) II railway track is susceptible to internal axial pressure, leading to joint damage and the potential for upwarp buckling of the track slab. This study employs model testing to derive the upwarp buckling deformation curve of the track slab under conditions of joint damage. An analytical expression for the upwarp buckling equilibrium path of the track slab is derived through the application of the energy principle. Validation of the outcomes is performed by the comparison with experimental data. The effects of initial upwarp amplitude, initial upwarp curve type, elastic modulus, thickness, and gravity load on the upwarp buckling response of the track slab were investigated. The results show that: 1) The upwarp deformation of the track slab in the narrow joint damage state is concentrated in a minor range on both sides of the joint, forming an inverted ‘V’ shape with concave ends. 2) The joint damage can significantly reduce the upwarp buckling critical temperature rise of the track slab. 3) The magnitude of the initial upwarp amplitude dictates the buckling mode of the track slab, while the initial upwarp curve predominantly influences the upwarp buckling critical temperature rise. Notably, an initial upwarp amplitude below 6.5 mm ensures the buckling resistance for up to a 60 °C temperature rise. 4) The increases in elastic modulus, gravity load, and track slab thickness can increase the upwarp buckling critical temperature rise. As the initial upwarp amplitude increases, the influence of these factors on the upwarp buckling critical temperature rise of the track slab gradually diminishes.
Key words: CRTS II slab track; Joint damage; Upwarp buckling; Deformation energy; Temperature load
机构:1西南交通大学,高速铁路线路工程教育部重点实验室,中国成都,610031;2西南交通大学,土木工程学院,中国成都,610031
目的:在持续高温条件下,CRTS II型轨道接缝部位极易损伤,导致轨道板存在上拱屈曲风险。本文旨在通过理论分析得到轨道板上拱屈曲平衡路径的解析公式,并探讨轨道板初始状态与结构参数(初拱幅值、初拱曲线型式、弹性模量、板厚和重力荷载等)对轨道板上拱屈曲响应的影响规律,为防治轨道板上拱提供参考。
创新点:1.开展模型试验,明确了轨道板上拱屈曲变形的特征;2.运用能量法原理,推导出轨道板上拱屈曲平衡路径的解析表达式。
方法:1.通过缩尺模型试验,得到轨道板在不同状态下的上拱屈曲变形曲线;2.通过理论推导,建立轨道板上拱幅值与温度荷载间的对应关系,验证理论方法的可行性和有效性;3.通过参数分析,量化表征轨道初始状态与结构参数对轨道板上拱屈曲的影响规律。
结论:1.轨道板在窄接缝损伤状态下的上拱变形曲线大致呈现两端下凹的倒"V"形状。2.轨道板上拱屈曲发展路径要经历稳定、上拱发展和后屈曲三个阶段;窄接缝缺损会导致上拱屈曲临界温升大幅下降。3.初拱幅值增大会导致轨道板上拱屈曲模式逐渐由"突跳屈曲"转变为"渐进屈曲"。4.轨道板上拱屈曲临界温升随初拱变形曲线边角约束的增强而减小。5.轨道板上拱屈曲临界温升与弹性模量、重力荷载以及板厚之间呈线性关系。
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DOI:
10.1631/jzus.A2400357
CLC number:
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On-line Access:
2025-08-27
Received:
2024-07-12
Revision Accepted:
2024-12-19
Crosschecked:
2025-08-28