基于车桥耦合振动的高速铁路系杆拱桥吊杆优化布置*

为研究吊杆布置形式对系杆拱桥动力特性的影响，以建成的某主跨度128 m系杆拱桥为工程背景，将车速、吊杆布置形式作为影响因素建立全桥有限元模型；车辆动力模型采用CRH2型动车组，并利用有限元软件ANSYS以及UM（Universal Mechanism）动力学分析软件联合进行仿真分析；研究桥梁结构的吊杆布置形式以及列车过桥运行速度对系杆拱桥结构自振及动力响应的影响。结果表明:斜吊杆拱、网状吊杆拱能明显提高面内振动的自振频率，对面外振动影响微弱；随着速度的增加，位移、加速度、冲击系数等大致呈增大的趋势，且速度等级越高其增大趋势越显著，桥梁的各项动力响应参数均在规范允许限值内；3种不同吊杆布置形式相比较，桥梁跨中横向位移基本不变，网状吊杆拱可以明显降低跨中竖向位移峰值。

Optimized arrangement of suspenders in tied arch bridge of high speed railway based on train bridge coupling vibration

In order to study the influence of suspender layout forms on the dynamic characteristics of tied arch bridge,taking a built up tied arch bridge with the main span of 128 m as the engineering background,a finite element model of the whole bridge was established by taking the train speed and suspender layout form as the influencing factors.The train dynamic model was CRH2 EMU,and the large scale finite element software ANSYS and UM (Universal Mechanism) were used to carry out the simulation analysis.From the perspectives of suspender layout form of bridge structure and the running speed of train passing through the bridge,the influence of them on the structure natural vibration and dynamic response of tied arch bridge was studied.The results showed that the inclined suspender arch and mesh suspender arch could obviously increase the natural vibration frequency of in plane vibration,but the influence on out of plane vibration was weak.With the increase of speed,the displacement,acceleration,impact coefficient and others generally increased,the higher the speed level,the more significant it was,and the dynamic response parameters of the bridge were all within the allowable limits of specification.Comparing the three different suspender layout forms,the lateral displacement of the bridge was basically unchanged,and the mesh suspension bridge could significantly reduce the peak vertical displacement in mid span.