大跨度上承式钢管混凝土拱桥地震响应的空间性  

Spatial Characteristics of Seismic Response of Long-Span Upper Concrete Filled Steel Tube Arch Bridge

作　　者：李子特[1,2] 王根会 武维宏[2] 简粤 LI Zite;WANG Genhui;WU Weihong;JIAN Yue(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Gansu ProvinceTransportation Planning,Survey&Design Institute Co.,Ltd.,Lanzhou 730030,China;Department of Basic Sciences,Lanzhou Institute of Technology,Lanzhou 730050,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070 [2]甘肃省交通规划勘察设计院股份有限公司,兰州730030 [3]兰州工业学院基础学科部,兰州730050

出　　处：《兰州交通大学学报》2023年第6期1-6,共6页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(51768037,52162043);甘肃省科技重点研发计划(22YF7GA043)。

摘　　要：为研究高震区大跨度上承式钢管混凝土拱桥地震响应的空间性,以西北山区Ⅷ度抗震设防的一座净跨400 m公路桥梁为例,采用反应谱和时程分析相结合的方法,对自振特性、多维组合输入下弦杆控制截面的轴力峰值及轴力时程进行了对比分析。结果表明:该类桥型质量分布具有明显的空间性,振型累计质量阶次差大,振动模态具有高度离散性;三维组合不一定是最不利输入,不同截面的最不利输入组合不同;弦杆各控制截面产生峰值轴力的时刻均不同,拱顶向拱脚截面逐次到达;上弦杆拱顶、L/4(L为跨度)截面及下弦杆拱顶在多维输入下的轴力时程较为一致,耦合性强;上弦杆拱脚及下弦杆拱脚、L/4截面在多维输入下的轴力时程很不一致,耦合性弱;地震响应具有显著的空间性。In order to study the spatial characteristics of seismic response of long-span concrete filled steel tube arch bridge in high seismic regions,taking a clear span 400m highway bridge with 8 degree seismic fortification in the northwest mountainous area as an example,the method of combining response spectrum and time history analysis is used to compare and analyze the natural vibration characteristics,the peak value of axial force and the time history of axial force of the chord control section under multi-dimensional combined input.The results show that the mass distribution of this type of bridge has obvious spatial characteristics,the accumulated mass order difference of vibration modes is large,and the vibration modes are highly discrete;Three-dimensional combination is not necessarily the most unfavorable input,and the most unfavorable input combination of different sections is different;The moment of peak axial force generated by each control section of the chord is different,and the arch crest reaches the arch foot section successively;The axial force time histories of top chord vault,L/4 section and bottom chord vault under multi-dimensional input are relatively consistent,in which the coupling is strong;The axial force time histories of the top chord arch foot and the bottom chord arch foot and the L/4 section under multi-dimensional input are very inconsistent,in which the coupling is weak;The seismic response has significant spatial characteristics.

关 键 词：空间性 反应谱 时程分析 上承式钢管混凝土拱桥 自振特性 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]