桥台及台后填土破坏的桥梁纵向地震碰撞响应  

Longitudinal seismic pounding effect of bridges abutment and backfilling damage

作　　者：李晓莉[1,2] 孙治国[1,2] 王东升[1,2] 石岩[1,2] 

机构地区：[1]大连海事大学道路与桥梁工程研究所,辽宁大连116026 [2]辽宁省公路工程重点实验室,辽宁大连116026

出　　处：《长安大学学报（自然科学版）》2015年第4期76-82,共7页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(51008041;51178071);教育部新世纪优秀人才支持计划项目(NCET-12-0751);中央高校基本科研业务费专项资金项目(3132014073;3132014326)

摘　　要：以汶川地震中发生严重破坏的高原大桥为工程背景,采用“多模型多平台”分析技术研究了主梁与桥台及台后填土的纵向碰撞效应及对全桥地震反应的影响。首先利用ANSYS软件建立桥台及台后填土非线性数值分析实体模型,基于静力Pushover分析模拟其在主梁撞击下水平力-位移关系。将上述力-位移关系引入到MIDAS软件中,主要以间隙单元模拟桥台及台后填土与主梁的碰撞作用,并建立全桥抗震分析模型。通过非线性时程分析及与震害对比,讨论了桥台及台后填土破坏、伸缩缝处安装碰撞缓冲装置等情况下主梁与桥台间的纵向碰撞响应。研究结果表明：桥台及台后填土破坏将增大桥台伸缩缝处桥台与主梁间的相对位移,增加了落梁风险;由于地震动输入和桥台位置不同,碰撞缓冲装置对台、梁间碰撞力的影响存在不确定性,建议碰撞缓冲装置刚度宜取为桥台及台后填土整体抗推刚度的1%~5%,并优先选用耗能型。Taking the severely damaged Gaoyuan bridge in Wenchuan earthquake as background, the seismic longitudinal pounding effect among girder, abutment and backfilling, and the influence of pounding on the seismic behavior of the bridge were analyzed by using multi model-multi platform analysis method. Firstly, the nonlinear 3D finite element model for the abutment and backfilling in Gaoyuan bridge was developed by ANSYS software, and the lateral force-displacement relationship of the abutment under girder pounding was obtained by static pushover analysis. The force-displacement relationship of the abutment was introduced into MIDAS software to simulate pounding effect on the bridge based on gap element. Also, the seismic analysis model of Gaoyuan bridge was established. Longitudinal pounding effect between girder and abutment was studied by nonlinear time-history analysis considering the damages to abutment and backfilling, and installation of pounding bumper device at expansion joint. Also, the analysis results were compared with those of damage investigation during Wenchuan earthquake. The results show that the pounding damage to abutment and backfilling would increase the gap between girder and abutment, and bridge superstructure may be unseated. Also, the influence of bumper device on pounding force between girder and abutment is random as a result of different earthquake excitations and abutment locations. It is finally suggested that the stiffness of pounding bumper device should be taken as 1 ~ ~ 5 ~ of the abutment and backfilling stiffness, and energy dissipation device would be preferentially selected in order to decrease pounding effect between girder and abutment. 4 tabs, 7 figs, 17 refs.

关 键 词：桥梁工程 桥梁抗震 碰撞 非线性时程分析 主梁-桥台-台后填土相互作用 

分 类 号：U443.21[建筑科学—桥梁与隧道工程] U442.54[交通运输工程—道路与铁道工程]