摘要
为研究大跨度斜拉桥桥塔在地震作用下的损伤演化过程,以某座主跨为432 m的铁路钢桁斜拉桥为例,基于OpenSEES软件建立桥梁有限元模型,采用增量动力分析法,对比了纵向地震波输入下以桥塔截面纵向钢筋应变与曲率为损伤指标的桥塔损伤程度,并选取钢筋应变指标用于桥塔在双向水平地震动作用下的损伤演化过程分析。结果表明:钢筋应变对于桥塔的损伤评价适用性更强;斜拉桥桥塔在地震作用下的损伤主要发生在塔底、中塔柱及上横梁处;纵向地震波输入时,塔底先出现损伤,接着是中塔柱,最后是上横梁处;双向水平地震动作用时,塔底仍最先受损,继而是上横梁处,最后是中塔柱;与纵向地震动单独作用时相比,双向水平地震动作用会显著增大桥塔的损伤程度,在进行桥塔的损伤评估时,应予以重视。
In order to investigate the damage evolution of long-span cable-stayed bridge tower under bi-directional ground motions,a 432 m-span railway steel truss cable-stayed bridge was modelled by the finite element software OpenSEES.The incremental dynamic analysis(IDA)method was adopted to compare the bridge tower damage degrees with damage index(DI)of the longitudinal reinforcement strain and curvature respectively under longitudinal seismic excitations.Then the damage index of the reinforcement strain was used to obtain the seismic damage evolution of the bridge tower subjected to bi-directional horizontal ground motions.The results show that the damage index of the reinforcement strain more applicable to the evaluation of the damage of the bridge tower.The damage of the cable-stayed bridge tower occurs mainly at the bottom and the middle of the bridge tower and the upper transverse beam when earthquake attacks.Excited by the longitudinal seismic motions,the bottom of the tower will be damaged first,followed by the middle tower column,and finally the upper transverse beam.When subjected to the bi-directional horizontal ground motions,the bottom of the tower will still be damaged first,followed by the upper transverse beam,and finally middle tower column.Compaving with the longitudiml earthquoke.The damage degree of the bridge tower will be significantly increased under bi-directional horizontal ground motions.Hence,more attention should be paid to bi-directional excitations during the damage evaluation of the cable-stayed bridge tower.
作者
李小珍
杨得海
赵鲁峰
辛莉峰
刘鸣
LI Xiaozhen;YANG Dehai;ZHAO Lufeng;XIN Lifeng;LIU Ming(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《铁道学报》
CSCD
北大核心
2021年第8期147-156,共10页
Journal of the China Railway Society
基金
国家自然科学基金(51678490)
国家重点研发计划(2017YFC1500803)
中国铁路总公司科技开发计划(2015G002-B)
关键词
地震损伤演化
钢桁斜拉桥
增量动力分析法
损伤指标
双向水平地震动
seismic damage evolution
steel truss cable-stayed bridge
IDA
damage index
bi-directional horizontal ground motions
