既有铁路桥梁声屏障的高速列车脉动风致响应

Response of Noise Barrier for Existing Railway Bridges under Impulsive Pressure Induced by High-Speed Train

采用SAP2000有限元软件,建立了既有桥梁声屏障的有限元模型,混凝土插板与H型钢立柱之间的连接采用位移和转角弹簧模拟.探讨了脉动力采用多点输入和一致输入,跨度16,24和32 m的铁路桥梁声屏障的动力响应,分析了声屏障的位移峰值、弯矩峰值和动力放大系数的分布特征.结果表明,常用跨度铁路桥梁声屏障的行波效应系数均小于1;声屏障立柱的位移和挑梁弯矩的最大值随桥梁跨度增大而减小;声屏障挑梁刚度过小,跨度16 m的铁路桥梁声屏障立柱的最大位移达15.5 mm.

A finite element model for noise barriers of the existing railway bridges was built by using an SAP2000 （structural analysis programme） software. In this model, the connections between stop plank and H-type steel columns are simulated using displacement springs and rotation springs. The dynamic responses of noise barriers for three types of railway bridges with a span of 16, 24 or 32 m were analyzed by considering both multiple support excitation and uniform excitation. The distribution characteristics of displacement amplitude, bending moment amplitude and dynamic magnification coefficient of noise barriers were investigated. The research results show that the factor of traveling- wave effect of noise barriers are below 1 for the three types of railway bridges. The maximum displacement of the columns and the bending moment of the cantilever beam decrease with the increase of bridge span. The maximum displacement of the columns for a 16 m span bridge reaches 15.5 mm due to the deficient stiffness of its cantilever beam.