The Hanjiatuo Changjiang River Bridge on Chongqing-Lichuan Railway is a passenger and freight double-track railway bridge and the main bridge of the bridge is the steel truss girder cable-stayed bridge with span arrangement (81+135+432+135+81) m.To guarantee the dynamic safety of the bridge,the control techniques for the structural vibration induced by the traveling train and earthquake and for the wind-induced vibration and wind-train-bridge coupling vibration of the steel truss girder were researched.The restraint of the pylons and main girder was designed into the combined control system,i.e.,the new type lock devices with control switches were used to control the vibration induced by the train,the hydraulic viscous dampers were used to control the earthquake responses and the lock devices were to work in collaboration with the dampers.At the bottom of the lower chords,the external flaring guide vanes were installed to suppress the vertical vortex-induced vibration of the truss girder at the low wind speeds.The hanging point of a guide vane was 0.6 m high,the dip angle was 5.5° and the sectional length of the guide vane in the longitudinal direction was the 1 time width of the vane.In terms of the wind-train-bridge coupling vibration analysis and in consideration of the safety factors concerned,the speed criteria for the train traveling at the different wind speeds were formulated.Verified by the operation of the trains on the bridge for years,the effects of the dynamic response control techniques of the bridge as mentioned have proved to be sound.%重庆至利川铁路韩家沱长江大桥为客货共线双线铁路桥,主桥采用(81+135+432+135+81)m钢桁梁斜拉桥.为保证其动力安全性,对行车和地震引起的结构振动、钢桁梁风致振动及风—车—桥系统耦合振动控制技术进行研究.该桥塔梁约束采用组合控制体系,即利用带控制开关的新型锁定装置控制行车引起的结构振动,利用液压粘滞阻尼器控制桥梁的地震响应,二者协同工作.采用在下弦杆底部设置外张导流板的措施抑制钢桁梁在低风速下的竖向涡激振动现象,导流板吊点高度设为0.6m、倾角设为5.5°,导流板纵向分段长度取为1倍导流板宽度.根据风—车—桥耦合振动分析,考虑安全因素,制定各种风速下列车运行时的车速标准.经多年通车运营检验,该桥动力响应控制技术效果良好.
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