400 km/h高速铁路两种简支梁桥竖向基频限值对比研究

随着莫斯科—喀山400 km/h高速铁路设计的逐步推进,国内已有的高速铁路设计规范对于简支梁桥基频限值的相关条文已不能满足设计需求。为避免列车通过桥梁时出现过大振动甚至产生共振,以莫喀高速铁路两种33. 1 m简支梁桥形式(混凝土简支箱梁桥、钢-混结合简支梁桥)为背景,通过车桥耦合振动分析,对简支梁桥的竖向挠度和基频限值进行研究。结果表明:列车活载类型对桥梁竖向基频限值有一定影响,这与车辆的车长和轴重等参数有关;对于跨度L=33. 1 m混凝土简支箱梁桥,中国高速列车对应的竖向基频限值为100/L,俄罗斯设计列车对应的竖向基频限值为140/L; 33. 1 m钢-混结合简支梁比33. 1 m混凝土简支箱梁桥的竖向基频限值更高。本研究成果可为400 km/h高速铁路简支梁桥设计提供参考。

Comparative Study on Limit Value for Basic Vertical Frequency of Two Types of Simply-supported Girder Bridge for High Speed Railway with Speed of 400 km/h

With the advancement of Moscow-Kazan 400 km/h high speed railway design,the existed native relative codes on limit value for basic frequency of simply-supported girder bridge cannot meet the demand.To avoid the excessive vibration or even resonance when the train passes through the bridge,two types of 33.1 m simply-supported girder bridge (a concrete simply-supported girder bridge and a steel-concrete composite girder bridge) for the Moscow-Kazan high speed railway were taken as the research objects.The vertical def lection and limit value for basic vertical frequency were studied by vehicle-bridge coupling vibration analysis.The results show that the vehicle active load mode has effects on the limit value for the basic vertical frequency of bridge,which is related with the vehicle length and axle load.As for the concrete simply supported box-girder bridge whose span L =33.1 m ,the limit value for the basic vertical frequency is 100/ L for CRH train and is 140/ L for Russian design train.The limit value for the basic vertical frequency of 33.1 m steel-concrete composite bridge is larger than that of 33.1 m concrete simply-supported girder bridge.The research results can provide a reference for the design of the 400 km/h high speed railway simply-supported girder bridge.