强震下大跨度连续梁桥损伤分析  

Damage Analysis of Long-Span Continuous Beam Bridges Under Strong Earthquakes

作　　者：贾宏宇[1] 吴炜昌 游刚 杨磊 彭奇慧 郑史雄[1] JIA Hongyu;WU Weichang;YOU Gang;YANG Lei;PENG Qihui;ZHENG Shixiong(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China;Yellow River Planning Survey and Design Academe Co.,Ltd.,Zhengzhou 450003,China;School of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中铁二院工程集团有限责任公司,四川成都610031 [3]黄河勘测规划设计研究院有限公司,河南郑州450003 [4]西南交通大学机械工程学院,四川成都610031

出　　处：《西南交通大学学报》2023年第6期1423-1431,共9页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金(52178169)。

摘　　要：连续梁桥结构常因地震发生损伤甚至倒塌而失去交通作用,研究强震下大跨度连续梁桥的损伤破坏机制对提高桥梁抗倒塌性能具有重要意义.基于有限元软件ANSYS/LS-DYNA,考虑桥墩材料非线性、损伤过程大变形非线性以及梁端非线性碰撞,建立大跨度连续梁桥在强震作用下的损伤三维数值模型,进行非线性分析,直观模拟大跨度连续梁桥在强震作用下的损伤破坏过程,从连续梁桥的应变与位移响应、桥墩损伤和梁-台间碰撞作用等方面分析了大跨度连续梁桥的地震损伤情况.研究结果表明:单向地震动输入与双向地震动输入作用下破坏模式基本一致,破坏模式由桥梁结构本身决定,地震动输入方式影响较小;大跨度连续梁桥的地震损伤是逐渐发展的过程,桥墩混凝土损伤因子不断累积达到0.99,固定墩底部发生受弯塑性破坏,桥梁发生损伤破坏.The continuous beam bridge is often damaged or even collapses due to the earthquake and thus loses its traffic function.Therefore,it is important to study the damage mechanism of large-span continuous beam bridges under strong earthquakes to improve the bridge collapse resistance.Based on the finite element software ANSYS/LS-DYNA,a three-dimensional numerical model of the damage of a large-span continuous beam bridge under strong earthquakes was established,which considered the material nonlinearity of the bridge pier,the large deformation nonlinearity of the damage process,and the nonlinear collision of the beam end.In addition,nonlinear analysis was performed to visually simulate the damage process of the large-span continuous beam bridge under strong earthquakes.The seismic damage of the large-span continuous beam bridge was analyzed in terms of strain and displacement response,pier damage,and girder-platform collision.The study results show that the damage modes of the one-way ground motion input and two-way ground motion input are basically the same,and the damage mode is determined by the bridge structure,and the ground motion input mode has less influence;the seismic damage of the large-span continuous beam bridge involves a gradual development process;the concrete damage factor of the bridge pier accumulates to 0.99;the bending plastic damage occurs at the bottom of the fixed pier,and the bridge is damaged.

关 键 词：大跨度连续梁桥 地震作用 破坏模式 损伤分析 桥墩损伤 

分 类 号：U442.5[建筑科学—桥梁与隧道工程]