柱式柔性墩隔震梁桥结构地震易损性分析  

Seismic fragility analysis on isolated bridges with flexible column piers

作　　者：张云[1,2] 谭平[1] 郑建勋[1] 周福霖[1] 

机构地区：[1]广州大学减震控制与结构安全国家重点实验室(培育),广州510405 [2]广西交通科学研究院,南宁530007

出　　处：《振动与冲击》2015年第16期48-54,共7页Journal of Vibration and Shock

基　　金：国家重点基础研究发展(973)计划项目(2011CB013606);国家自然科学基金联合基金项目(1334209);广西科技攻关项目(桂科攻1355008-2);广西科技攻关计划(14124004-4-5)

摘　　要：对柱式柔性桥墩刚度较小下部构件结构形式的中小跨径桥梁,利用铅芯橡胶支座双线性恢复力特性,通过调节桥梁下部结构整体刚度,改变地震力在不同墩柱间的分配可提升桥梁整体抗震能力。定义桥梁损伤的5种状态,归纳出以曲率延性判定5种损伤水平的量化指标,并与桥墩墩顶位移相关联。选典型桥梁建立有限元模型进行动力弹塑性分析,将隔震改造前后桥梁墩顶位移概率需求与地震易损性进行对比。分析表明,采用柔性桥墩的梁桥结构进行合理隔震改造后,只要保证隔震支座体系正常运行,桥梁整体在大震作用下的抗震水平可明显提升。Structures with lower members of smaller stiffness, such as flexible column piers, have become the most widespread kind of structure in small or medium-span bridges. For this type of bridge, making use of the LRB bilinear restoring force characteristics for adjusting the overall stiffness of the bridge substructure to change the seismic force distribution between different piers can improve the overall seismic capacity. Five states of bridge in juries were defined, and quantitative indicators based on curvature ductility, and related to the top displacements of bridge piers were summarized to determine the level of these five kinds of damages. A typical bridge was selected to establish a finite element model for dynamic elastic-plastic analysis. The pier top displacement probability demand and seismic vulnerability of bridges installed with and without isolation devices were compared. The analysis shows that the application of flexible column pier structure to achieve reasonable isolation, as long seismic level of the overall bridge can be evidently improved. as the normal operation of isolation bearings is ensured, the

关 键 词：隔震桥梁 柱式柔性墩 易损性分析 损伤水平 铅芯橡胶支座 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]