梁式拱上建筑地震响应中拱圈的弹性滤波效应  

Elastic filtering effect of arch ring in seismic response of girder spandrel construction

作　　者：刘冰 郭增伟 朱锡东 LIU Bing;GUO Zengwei;ZHU Xidong(State Key Laboratory of Mountain Bridge and Tunnel Engineering,Chongqing Jiaotong University,Chongqing 400074,China;School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学省部共建山区桥梁及隧道工程国家重点实验室,重庆400074 [2]重庆交通大学土木工程学院,重庆400074

出　　处：《地震工程与工程振动》2021年第4期209-220,共12页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51878106);重庆市自然科学基金面上项目(cstc2019jcyj-msxmX0818);重庆市教委科学技术研究重点项目(KJZD-K201900705);桥梁结构抗震技术交通行业重点实验室开放基金项目(201501)。

摘　　要：以某钢筋混凝土拱桥为研究对象,采用有限元软件SAP2000进行弹塑性时程分析来研究主拱圈的弹性滤波。通过提取拱上建筑桥墩基底的加速度时程响应并进行功率谱变换,分析主拱圈弹性滤波后桥墩基底的加速度能量分布特征;通过与地震波自身功率谱对比,评价主拱圈对拱上建筑的滤波效应;再分别从加速度、位移等角度分析了梁式拱上建筑和相同形式的梁桥的地震响应的区别,讨论主拱圈对拱上建筑的“弹性滤波”的影响。研究发现:拱圈的弹性滤波削减了输入到拱上建筑中地震动的高频的振动能量,放大了低频段内的能量,拱圈的刚度越小,其滤波作用越显著。滤波作用对拱顶附近拱上建筑的影响远大于拱脚,弹性滤波使桥墩更易进入塑性阶段,桥墩顶部位移和加速度、支座位移以及梁体位移均大于相同结构的连续梁。In this paper,taking a long-span reinforced concrete arch bridge as the research object,SAP2000 is adopted to conduct elastoplastic time-history analysis on the model,extract the time-history response of acceleration of the pier base of the arch building and carry out power spectrum transformation on it,and analyze the acceleration energy distribution characteristics of the pier base after the elastic filtering of the main arch circle.By comparing with the power spectrum of the seismic wave itself,this paper evaluates the filtering effect of the main arch ring on the spandrel structure.Then the difference of seismic response between the beam arch building and the beam bridge of the same form is analyzed from the aspects of acceleration and displacement,and the influence of the main arch ring on the"elastic filtering"of the arch is discussed.The results show that:The response spectrum acceleration of the spandrel column near the vault in the short period section and the column on the arch near the arch foot in the middle period section are amplified by the elastic filtering selectivity of the arch ring.The vibration energy input to the high frequency components of ground motion in the arch building is reduced,and the acceleration energy in the low frequency is amplified.The smaller the stiffness of arch ring is,the more significant the filtering effect will be.The influence of elastic filtering of arch ring on the building on the arch near the arch crown is far greater than that on the arch foot.The elastic filtering of arch ring makes the pier enter the plastic stage more easily.The displacement and acceleration of pier top,support displacement and the displacement of beam body are all larger than those of continuous beam with the same structure.

关 键 词：主拱圈 弹性滤波 能量分布特征 相同形式梁桥 地震响应 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]