高铁济南黄河特大桥钢桁梁主桥动力性能研究

摘要

Jinan Yellow River extra major bridge is a four-track railway bridge for both Beijing-Shanghai high-speed railway and Taiyuan-Qingdao passenger dedicated line.Through type continuous steel truss of (112+3×168+112) m was used for its main bridge.By combining the methods of field test and finite element analysis,the dynamic behaviors of the main bridge,train operation safety and stability were researched.The results show that both the lateral and vertical rigidity of bridge meet the requirements of related specifications and design files.The tested lateral and vertical first natural frequency of the beam is 1.57 and 1.72 Hz respectively,which is far away from the lateral and vertical forced frequency of EMU under test speed and resonance does not appear.The maximum vertical dynamic increment of beam subjected to EMU is 3％ of design load,and the maximum vertical acceleration of beam (after 20 Hz low-pass digital filter is done) is less than 0.5 m · s-2.Both the lateral and vertical amplitudes of beam are very small,which can meet the operation requirements of 300 km · h-1 EMU.The safety index of EMU passing through the main bridge with ballast track is less than the allowable value.Both the lateral and vertical stability indexes of carbody are less than 2.5.There is little difference between the tested results of vehicle dynamic response of EMU passing through different track structure sections of the main bridge and approach bridge.%高铁济南黄河特大桥为京沪高铁和太青客运专线四线共建桥,其主桥采用(112+3×168+112)m下承式连续刚性梁柔性拱型式.采用现场测试与有限元分析相结合的方法,对济南黄河特大桥钢桁梁主桥的动力性能、行车安全性和平稳性进行研究.结果表明:桥梁横向、竖向刚度均满足相关规范和设计文件要求；实测梁体横向和竖向1阶自振频率分别为1.57和1.72 Hz,与测试速度内动车组的横向和竖向强振频率相距较远,未出现共振；动车组作用下的梁体最大竖向动力增量为设计荷载的3％,梁体最大竖向振动加速度(20 Hz低通数字滤波后)均小于0.5m·s-2,梁体横向和竖向振幅均较小,能够满足300 km·h-1动车组运行要求；动车组通过主桥有砟区段的安全性指标小于允许值,车体横向和垂向平稳性指标均小于2.5,动车组车辆动力学响应在主桥和引桥不同轨道结构线路区段的实测结果差别不大.