摘要
大跨桥梁跨径大、刚度小,在移动荷载作用下产生较大变形,严重影响行车安全。因此,大跨桥梁车桥耦合振动的行车安全评判问题一直是桥梁工程领域的研究重点。针对某悬索桥,考虑外荷载随机因素,采用虚拟激励法与确定性时程法求得行车安全指标的概率特征参数;借助概率论构建行车安全指标的概率分布函数;通过设定置信水平来确定安全指标阈值,并采用时域样本进行验证;最后,采用8节编组列车以悬索桥为例进行算例分析。研究结果表明,行车安全指标(轮重减载率、脱轨系数、横向力)的概率密度曲线拟合效果较好,能较为准确地拟合样本;根据置信度确定的安全指标阈值能够很好地控制其时域样本,失效样本个数均小于置信度确定数量;计算效率比统计方法高出1个数量级,可以快速、准确地评判列车运行安全。
Long-span bridges,characterized by long spans and low stiffness,undergo significant deformations under moving loads,which seriously affects operational safety.Therefore,the assessment of operational safety for vehicle-bridge coupled vibration of long-span bridges has always been a key research focus in bridge engineering.Taking a specific suspension bridge as the object and considering the randomness of external loads,the pseudo-excitation method and the deterministic time-history method were employed to obtain the probabilistic characteristic parameters of the operational safety indicators.Probability theory was applied to construct the probability distribution functions of the operational safety indicators.The safety indicator thresholds were determined by setting the confidence level and were verified using time-domain samples.Finally,a case study was conducted using an 8-carriage train on the suspension bridge as an example.The results demonstrated that the probability density curves of the operational safety indicators(wheel load reduction rate,derailment coefficient,and lateral force)were well fitted,enabling relatively accurate representation of the samples.The safety indicator thresholds determined based on the confidence level could effectively control their time-domain samples,with the number of failure samples being lower than the number determined by the confidence level.The computational efficiency was one order of magnitude higher than that of statistical methods.The proposed method can rapidly and accurately evaluate train operational safety.
作者
周子骥
陈克坚
郑晓龙
杨国静
ZHOU Ziji;CHEN Kejian;ZHENG Xiaolong;YANG Guojing(Science and Technology Research Institute,China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)
出处
《铁道标准设计》
北大核心
2025年第12期90-94,共5页
Railway Standard Design
基金
中国中铁股份有限公司科技研究开发计划课题(2022-重点-08)。
关键词
高速列车
车桥耦合振动
行车安全指标
悬索桥
随机外荷载
概率分布
high-speed train
vehicle-bridge coupled vibration
operational safety indicators
suspension bridge
random external load
probability distribution
