伸缩缝刚度对大跨度悬索桥动力特性的影响

发布时间：2018-01-20 11:12

本文关键词： 大跨度悬索桥伸缩缝抗推刚度自振特性地震响应　出处：《震灾防御技术》2017年03期 　论文类型：期刊论文

【摘要】：伸缩缝作为大跨度桥梁与引桥之间的重要连接构件,其抗推刚度及可能存在的变异性对主桥及引桥动力特性的影响不可忽略。本文建立了大跨度悬索桥及引桥的有限元模型,采用弹簧单元模拟加劲梁与引桥箱梁之间的伸缩缝,分析伸缩缝刚度对悬索桥及引桥自振特性及其地震响应的影响规律。分析结果表明:伸缩缝刚度对加劲梁的横弯振型、竖弯与纵飘耦合振型的频率有明显的影响;伸缩缝刚度的变化会导致加劲梁与引桥的振型相互耦合,同时这些振型的频率发生相应的突变,当伸缩缝刚度较大时,加劲梁两个竖弯与纵飘的耦合振型解耦成为独立的竖弯和纵飘振型;当引桥与悬索桥加劲梁的纵飘振型发生耦合时,在纵向和竖向地震作用下的悬索桥及引桥的地震响应达到最小。伸缩缝刚度对悬索桥动力特性影响的分析可为悬索桥的模态参数确认、损伤识别、抗震性能分析提供有价值的借鉴。
[Abstract]:Expansion joint is an important connecting member between long span bridge and approach bridge. The influence of the anti-push stiffness and the possible variability on the dynamic characteristics of the main bridge and the approach bridge can not be ignored. The finite element model of the long-span suspension bridge and the approach bridge is established in this paper. Spring element is used to simulate the expansion joint between stiffened beam and box girder of approach bridge. The influence of expansion joint stiffness on the natural vibration characteristics and seismic response of suspension bridge and approach bridge is analyzed. The results show that the stiffness of expansion joint affects the transverse bending mode of stiffened beam. The frequency of vertical bending and longitudinal floating coupling mode has obvious influence; The stiffness of the expansion joint will lead to the coupling of the modes of the stiffened beam and the bridge, and the frequency of these modes will mutate accordingly, when the stiffness of the expansion joint is large. The coupling modes of two vertical bending and vertical floating of stiffened beam are decoupled into independent vertical bending and longitudinal floating modes. When the longitudinal floating vibration mode of the stiffened beam of the approach bridge and the suspension bridge is coupled. The seismic response of suspension bridge and approach bridge under longitudinal and vertical seismic action reaches the minimum. The analysis of the influence of expansion joint stiffness on the dynamic characteristics of suspension bridge can be used to confirm the modal parameters and identify the damage of suspension bridge. Seismic performance analysis provides valuable reference.
【作者单位】：广东省地震局;中国地震局地震监测与减灾技术重点实验室;广东省地震预警与重大工程安全诊断重大实验室;
【基金】：地震科技星火计划(XH16031) 广东省地震预警与重大工程安全诊断重点实验室建设项目(2011A060901006) 中国地震局地震监测与减灾技术重点实验室自主课题
【分类号】：U441.3;U448.25
【正文快照】： 引言悬索桥的模态参数是抗震、抗风、损伤识别和健康监测等研究领域的重要参数之一,主要通过有限元模态分析和基于现场振动测试的模态试验分析获得。对同一座桥梁,采用两种方式获得的模态参数往往有一定的差别,如对虎门大桥(章关永等,1999)和润扬大桥悬索桥(刘毅等,2007)的动

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