摘要
大跨度悬索桥的抗震研究主要针对纵向对称结构,而主缆边跨不对称布置会改变桥梁的地震反应特性,目前,我国已建成不少主缆不对称布置的悬索桥。为研究主缆纵向不对称特大悬索桥的地震反应特性,本文以一座主跨1560 m的悬索桥为背景,采用SAP 2000软件,建立了三个不同边跨的有限元模型,并进行了一致激励和非一致激励下桥梁关键地震反应的对比分析。结果表明:在一致地震激励下,主缆纵向不对称布置主要会影响主塔的纵向地震反应,主缆边跨大幅减小会明显减小对应侧塔底弯矩,增大另一侧塔底弯矩,同时显著减小塔顶位移;主缆纵向不对称布置不会改变行波效应的影响规律,但会使地震反应对视波速更为敏感。
Seismic research on long-span suspension bridge mainly focuses on symmetrical longitudinal structures,but the asymmetric layout of the main cable side span will change the seismic response characteristics of bridge.Currently,many suspension bridge with the asymmetric layout of main cables have been built in China.In order to study the seismic response characteristics of a large suspension bridge with longitudinal asymmetry of main cables,a suspension bridge with a main span of 1560 m is taken as the background in this paper.Using SAP 2000 software,three finite element models with different side spans are established,and the key seismic responses of the bridge under consistent excitation and non-consistent excitation are compared and analyzed.The results show that under uniform seismic excitation,the longitudinal asymmetrical layout of the main cable mainly affects the longitudinal seismic response of the main tower.A large reduction of the main cable side span will significantly reduce the bending moment of the corresponding side tower,increase the bending moment of the other side tower,and significantly reduce the tower top displacement.The longitudinal asymmetry of the main cable does not change the influence of traveling the wave effect but makes the seismic response more sensitive to apparent wave velocity.
作者
钱晋
华新
叶爱君
QIAN Jin;HUA Xin;YE Aijun(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;China Design Group Co Ltd,Nanjing 210014,China)
出处
《土木工程与管理学报》
2021年第6期178-182,共5页
Journal of Civil Engineering and Management
关键词
大跨度桥梁
地震反应
行波效应
long-span bridge
seismic response
traveling wave effect
