连续梁桥变截面桥墩自振频率计算的合成法

Frequency composition method of tapered pier of tall-piered continuous beam bridge

采用瑞利法和Southwell频率合成法,将基频表示成各惯性元与复位元所组成的子系统的频率合成,导出了变截面桥墩自振频率下限的计算公式,然后用有限元模型验证该公式的正确性,并分析了不同变截面系数及不同类型的弹簧约束刚度对变截面桥墩自振频率的影响,对桥墩结构状态的评定具有一定的参考作用。

The formula for lower limit of natural frequency of tapered pier of continuous beam bridge were derived by the combination of Rayleigh and Southwell method.The natural frequency of tapered pier was composed of the sum of frequency of each subsystem consisted in inertia component and deformable component.Then finite element analysis was used to establish models to verify the approach.The influence of different taper ratios and different constraint rigidity is also discussed.The formula is suitable to tower structures.