铁路不等跨简支梁桥组合减震系统减震机理及影响参数研究  

Damping mechanism and influential parameters of a hybrid shock absorption system for railway simply-supported girder bridges with unequal spans

作　　者：白维刚 王军文 邢晨鹏[2] 彭涛 郭进 BAI Weigang;WANG Junwen;XING Chenpeng;PENG Tao;GUO Jin(Campus Construction Management Department,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Key Laboratory of Roads and Railway Engineering Safety Control,Ministry of Education,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]石家庄铁道大学校园建设管理处,石家庄050043 [2]石家庄铁道大学土木工程学院,石家庄050043 [3]石家庄铁道大学省部共建交通工程结构力学行为与系统安全国家重点实验室,石家庄050043 [4]石家庄铁道大学道路与铁道工程安全保障省部共建教育部重点实验室,石家庄050043

出　　处：《振动与冲击》2022年第2期208-216,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51508347,51508351);河北省自然科学基金(E2015210038,E2019210215);河北省高等学校科学技术研究项目(ZD2019124);国家土建结构预制装配化工程技术研究中心开放课题项目(2018CPCCE-K03)。

摘　　要：为了解决地震作用下铁路不等跨简支梁桥(simply-supported girder bridges,SSGB)发生邻梁和梁墩碰撞,引起伸缩缝和过渡墩破坏,甚至造成落梁的问题,针对传统减震装置的局限性,基于功能分离思想,研发了一种新型屈曲约束支撑(buckling-restrained brace,BRB)-拉索限位器组合减震系统。在阐述组合减震系统的构造形式和工作原理的基础上,提炼出系统的力学模型;然后将减震系统用于铁路不等跨SSGB,采用OpenSees建立考虑碰撞的动力弹塑性数值模型,研究了组合减震系统的减震机理;最后系统分析了BRB初始刚度、启动阈值及伸缩缝间隙等参数对其减震性能的影响。结果表明:组合减震系统能够有效控制梁体和过渡墩的纵向地震响应,显著提高SSGB的整体抗震性能;BRB初始刚度越大,邻梁相对位移的减小程度越大;BRB启动阈值应根据伸缩缝间隙进行合理选择,并在设计时加大对拉索限位器的重视程度;当伸缩缝间隙超过5 cm,系统减震效果更好。In order to solve the problem of collision between adjacent decks or beams and piers of railway simply-supported girder bridges(SSGB)with unequal spans under earthquake,which is easy to cause the damage of expansion joint and transition pier,and even cause the falling of girders.Aiming at ovecoming the limitation of traditional damping devices,a new shock absorption system composed of a buckling-restrained brace(BRB)and a cable restrainer was developed based on the function separation idea.On the basis of the description of the structure and working principle of the hybrid shock absorption system,its mechanical model was established.Then the system was applied to a railway SSGB with unequal spans,and the dynamic elastic-plastic numerical model of the bridge considering collisions was established by OpenSees,and the damping mechanism of the system was studied.Finally,the influences of the initial stiffness,starting threshold of BRB and expansion joint gap on its seismic performance were analyzed systematically.The results show that the hybrid shock absorption system can effectively control the longitudinal seismic responses of girders and transition pier,significantly improve the overall seismic performance of the SSGB;the greater the initial stiffness of the BRB,the greater the reduction of relative displacement of adjacent decks;the starting threshold of the BRB should be reasonably selected according to the gap between expansion joints,and more attention should be paid to the cable restrainer in design;when the gap of expansion joint is greater than 5 cm,the damping effect of the system is better.

关 键 词：铁路不等跨简支梁桥(SSGB) 组合减震系统 碰撞效应 屈曲约束支撑(BRB) 拉索限位器 减震机理 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]