摘要
为研究重载铁路钢桁梁桥在扭曲变形条件下的疲劳寿命问题,以黄骅—大家洼铁路80 m简支下承式钢桁梁桥为对象进行疲劳寿命评估。通过车-桥耦合动力分析获得关键杆件的动应力时程曲线,使用雨流计数法分析应力幅分布,并基于Miner线性累积损伤理论计算累积疲劳损伤,对比桥梁扭曲变形前后下弦杆疲劳寿命变化规律,进一步探讨车速及轨道不平顺对疲劳损伤的影响模式。研究表明,在现有运输规模条件下,桥梁所有关键杆件在设计使用年限内不会发生疲劳破坏。其中,纵梁疲劳损伤最大,最容易出现疲劳破坏;与扭曲变形前相比,变形后的桥梁杆件在凸出侧的疲劳损伤有所减小,剩余寿命增加,而凹陷侧疲劳损伤增加,剩余寿命降低;随着列车速度提高,疲劳损伤呈缓慢下降趋势,而轨道不平顺对疲劳损伤的影响更显著,轨道状态越差,累积疲劳损伤越大。研究结果表明,该桥在现有运营条件下的疲劳寿命符合设计要求,但需关注纵梁和扭曲变形凹陷侧构件的疲劳状况,建议加强轨道平顺性的维护,以确保桥梁的长期安全性。
To investigate the fatigue life of heavy-haul railway steel truss bridges under distortion and deformation condition,this study conducted a fatigue life assessment of an 80 m simply supported steel truss bridge on the Huanghua-Dajiawa Railway.Dynamic stress time histories of critical members were obtained through vehicle-bridge coupled dynamic analysis,and rainflow counting method was utilized to analyze the distribution of stress ranges.Then,the cumulative fatigue damage was calculated based on Miner's cumulative damage theory.The fatigue life of lower chord members before and after deformation was compared,and the effects of train speed and track irregularity on fatigue damage were further explored.The results indicate that,under the current transportation scale,all critical members of the bridge will remain free from fatigue failure within the design service life.Among all member types,the longitudinal beams exhibit the most serious fatigue damage and are prone to fatigue failure.Compared to healthy status,the fatigue damage of the bridge members on the convex side decreases after distortion and deformation,leading to an increase in residual life.Whereas,the fatigue damage on the concave side increases,resulting in a decrease in residual life.Additionally,fatigue damage shows a slow downward trend with the increasing of train speed,while the influence of track irregularity on fatigue damage is significantly more pronounced,with greater accumulated fatigue damage observed under poorer track conditions.The findings indicate that the bridge's fatigue life meets the design requirements under current operational conditions.However,attention should be paid to the fatigue conditions of longitudinal beams and components on the concave side of the deformation.It is recommended to enhance the maintenance of track irregularity to ensure the long-term safety of the bridge.
作者
江路路
王志航
王闯
JIANG Lulu;WANG Zhihang;WANG Chuang(Guoneng Huangda Railway Co.,Ltd.,Dongying 257091,China;School of Civil Engineering of Beijing Jiaotong University,Beijing 100044,China)
出处
《铁道勘察》
2025年第3期121-127,155,共8页
Railway Investigation and Surveying
基金
国能朔黄铁路发展有限责任公司科技创新项目重点课题(朔服务(2023)235号)。
关键词
重载铁路
钢桁梁桥
扭曲变形
车桥耦合
雨流计数法
疲劳寿命评估
heavy-haul railway
steel truss bridge
distortion and deformation
vehicle-bridge coupling
rainflow counting method
fatigue life assessment
作者简介
江路路(1987-),男,2012年毕业于石家庄铁道大学土木工程专业,工学学士,工程师,E-mail:18366958882@163.com。
