摘要
为研究行波效应下铁路大跨钢桁拱桥地震反应的影响规律,以某490m钢桁拱桥为研究对象,采用SAP2000软件建立全桥动力计算模型,进行了非一致激励下地震响应分析。基于相对运动法的基本原理及位移输入模式,有效分离了行波效应下的拟静力分量和动力分量。结果表明:行波效应对大跨上承式铁路钢桁拱桥的地震反应影响显著,从影响杆件区域范围及量值两个角度衡量,行波效应对拱圈弦杆轴力的影响明显大于对应弯矩的影响。行波效应将使拱顶弦杆轴力显著增大,若不考虑行波效应,将严重低估拱顶杆件的内力响应。与一致激励相比,行波效应使拱顶区域的竖向位移显著增大,使拱顶区域的纵向位移减小。拟静力分量对拱顶纵向及竖向位移影响显著,尤其对拱顶纵向位移。随着视波速的增加,拱顶纵向位移拟静力分量逐渐增大,而竖向位移拟静力分量逐渐减小,拱顶纵向及竖向位移的拟静力分量均与动力项同向,导致总位移均明显大于对应的动力位移。
In order to study the law of seismic response of railway long-span steel truss arch bridges under traveling wave effect,a deck-type railway steel truss arch bridge with the span of 490m was taken as the research object,SAP2000 software was used to establish the dynamic calculation model of the whole bridge,the seismic response under non-uniform excitation was analyzed.Based on the basic principle of a relative motion method and a displacement input model,the quasi-static and dynamic components under traveling wave effect were separated effectively.The results show that the traveling wave effect has a significant influence on the seismic response of the long-span deck-type railway steel truss arch bridge,the influence of traveling wave on the axial force of the arch chord is obviously greater than that of the corresponding bending moment from the angle of the influence on the range and magnitude of the bar.If the traveling wave effect is not taken into account,the traveling wave effect will significantly increase the axial force of the arch chord and the internal force response of the arch member will be seriously underestimated.Compared with the uniform excitation,the traveling wave effect increases the vertical displacement of the vault region and decreases the longitudinal displacement of the vault region.The quasi-static component has a significant influence on the longitudinal and vertical displacement of the arch,especially on the longitudinal displacement of the arch.With the increase of apparent wave velocity,the quasi-static component of longitudinal displacement of vault increases gradually,while that of vertical displacement decreases gradually.The quasi-static components of the longitudinal and vertical displacements of vaults are in the same direction as the dynamic terms,resulting in that the total displacements are significantly larger than the corresponding dynamic displacements.
作者
张永亮
王云
虞庐松
陈兴冲
刘正楠
ZHANG Yongliang;WANG Yun;YU Lusong;CHEN Xingchong;LIU Zhengnan(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第12期213-220,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(51768037)
甘肃省科技计划(17JR5RA103)。
关键词
铁路钢桁拱桥
行波效应
位移输入
拟静力分量
动力分量
railway steel truss arch bridge
traveling wave effect
displacement input
quasi-static component
dynamic component
