上承式钢筋砼拱桥行波效应分析

Analysis of the Traveling Wave Effect of Deck Reinforced Concrete Arch Bridge

根据国外一座大跨拱桥的尺寸及选定的振动台尺寸进行等效缩尺,并完成振动台试验.利用有限元软件ABAQUS验证模型准确性并分析行波效应.拱圈、立柱、桥面采用实体单元建立,地震波取适用于二类场地的兰州波,加速度时程的峰值调整为0.1 g,输入水平和竖向地震动,其中竖向地震动取水平地震的0.65倍.分析了钢筋混凝土拱桥在二类场地条件下由不同波速产生的行波效应对拱桥拱圈两侧拱脚、1/4截面、3/4截面以及1/2截面的轴力、弯矩以及位移的影响.研究结果表明:与一致激励作用相比,在行波效应作用下,拱圈各关键截面的轴力随着波速增加呈现下降的趋势;面内弯矩则呈现出先减小再增大,随后再次减小,最后趋于平稳的趋势;在位移方面行波效应对于1/4、1/2、3/4截面的位移均有显著影响.

Based on the size of a foreign long-span arch bridge,the equivalent scale of the prototype bridge and the shaking table test are carried out according to the size of the shaking table,and the finite element software ABAQUS is used to model and verify the analysis of the traveling wave effect.The arch ring,column and bridge deck are built with solid elements.The seismic wave is Lanzhou wave applicable to Class II site.The acceleration time history is adjusted to 1m/s2,and the longitudinal and vertical ground motions are input.The vertical seismic motion is 0.65 times of the longitudinal earthquake.This paper analyzes the influence of the traveling wave effect produced by different wave velocities on the axial force,bending moment and the displacement of the arch foot,1/4 section,3/4 section and 1/2 section of the arch ring of the reinforced concrete arch bridge under the Class II site conditions.The research results show that under the action of traveling wave effect,the axial force of each key section of the arch ring decreases with the increase of wave velocity.The in-plane bending moment first decreases,then increases,and then decreases again.It finally tends to be stable.In terms of the displacement,the traveling wave effect has a significant impact on the displacement of 1/4,1/2,and 3/4 sections.