摘要
地震时桥梁端部易产生变位,对桥上列车的行车安全构成威胁。为研究基于梁端变位对震时列车行车安全性进行评价的方法及相应限值标准,建立车轨耦合振动模型。将梁端变位对应的轨道变形曲线作为静态不平顺施加到轨道上,地震导致的轨底激励以正弦波的形式通过大质量法作用于轨底,分析给定梁端变位、轨底激励及运行车速对列车行车安全性的影响。研究结果表明:列车脱轨风险与三者均正相关,因此在确定地震时梁端变位限值时应同时考虑三者的影响。通过二分法搜索得到不同频率和幅值的正弦激励下、列车以不同车速运行时,脱轨系数和轮重减载率达到限值时对应的3种形式梁端变位的界限值,取97.5%保证率得到不同车速对应的梁端变位限值。以5跨高铁32 m标准跨简支梁桥为例,进行地震作用下车-轨-桥耦合振动分析,得到按动态方法确定的梁端变位临界值,通过与按静态变位加轨底激励计算得到的震时梁端变位限值进行对比,验证了所提出的变位限值的正确性。依据所提出的方法和梁端变位限值,可采用地震下桥梁动力分析代替车轨桥耦合振动分析对高铁列车震时行车安全做出快速评价。
Beam end displacements are prone to occur during the earthquake,which can endanger the running trains on the bridge.In order to investigate the evaluation method and the associated criteria for train safety based on beam end displacement under earthquake,a vehicle-track coupled vibration model was established.The track deformation curves corresponding to the beam end displacement were applied to the rail as the static track irregularities.The rail bottom excitation caused by earthquake was acted on the rail bottom in the form of sinusoidal wave by the large-mass method.The effects of beam end displacement,track vibration and speed on the safety of trains were analyzed.The calculated results show that the risk of train derailment was positively correlated with these factors,so the influence of the three should be considered when determining the limit values of beam end displacement during earthquake.The limit values of the three types of beam end displacements corresponding to the threshold values of derailment coefficient or the wheel unloading rate are obtained through the binary search method,considering different train speeds and various frequencies and amplitudes of the sinusoidal excitation.The 97.5%guarantee rate is applied to obtain the beam end displacement limit corresponding to different train speeds.The vehicle-track-bridge coupling vibration analysis is carried out under earthquake excitation by taking a 5-span high-speed railway simply supported bridge with a standard span of 32 m as an example.The limit of the beam end displacement determined by the dynamic method is obtained.It is compared with the result from static track displacement plus rail bottom excitation.The consistency of them shows the correctness of the beam end displacement limit.According to the proposed method and the beam end displacement limit,the bridge dynamic analysis under earthquake can be used instead of the vehicle-track-bridge coupling vibration analysis.This facilitates a rapid evaluation of the safety of high-speed trains
作者
贺建帅
李奇
王君杰
HE Jianshuai;LI Qi;WANG Junjie(Yunji Intelligence Engineering Co.,Ltd.,Shenzhen 518000,China;College of Civil Engineering,Tongji University,Shanghai 200092,China)
出处
《铁道科学与工程学报》
EI
CAS
CSCD
北大核心
2023年第5期1543-1554,共12页
Journal of Railway Science and Engineering
基金
国家重点研发计划课题(2018YFC1504306)。
关键词
梁端变位
高铁列车
行车安全
地震
车桥耦合
beam end displacement
high-speed railway trains
train safety
earthquake
vehicle-bridge coupling
