摘要
输入地震动的选取是桥梁抗震分析中的重要环节,不同的输入地震动引起的桥梁结构反应有显著差异。为了对铁路桥梁抗震设计地震动的选择提供定量依据,将“最不利设计地震动”的概念拓展并应用到桥梁抗震领域,研究典型铁路梁桥在不同地震动作用下的结构响应,得到基于结构相应参数的输入地震动破坏能力排序。首先确定了桥梁地震动输入以及评价指标,使用OpenSees对桥墩模型输入大量地震动记录进行有限元分析,通过调幅手段研究幅值与单一参数的关系,并引入颜色映射理论研究幅值与多参数的关系。研究表明:(1)当较低幅值地震动作用在结构上时,结构的地震响应与第一周期反应谱值相关性最好;(2)随着幅值的增加,结构周期增长,地震响应与更长周期反应谱值以及速度、位移参数、持时参数等的相关性会逐步提高;(3)通过动力时程计算并对墩顶位移进行比较,给出了模型在设定地震作用下的排序,结果可为相关桥梁结构的输入地震动选取提供参考。
Selection of input ground motion is critical in seismic analysis of bridges.The concept,the most unfavorable design ground motion,has been widely used in building structures.This paper extended this concept to the field of bridges to study the sequence of structural responses of bridges under ground motion excitation.In this paper,different ways of measuring input ground motion and the damage index were introduced.The OpenSees finite element analysis was used to input a large number of ground motion records into the pier model.The relationship between response and single ground motion intensity measure was studied by means of strip method.The relationship between response and multi-parameter was studied by using color mapping method.Finally,the displacement of the pier top was compared through the dynamic time history calculation.Comparing with this model,the records of the model under the peak ground motion are given.The results show that(1)For lower level ground motion,the correlation between the seismic response and the response spectrum of the first period is the best when applied to the structure;(2)with the increase of the input ground motion level,the period of the structure increases.The correlation between the seismic response and the response spectrum of the longer period,as well as the velocity,displacement and duration parameters will gradually increase.For structure similar to the model in this paper,the records can be used as the input design ground motion.
作者
胡进军
樊圆
来庆辉
谢礼立
HU Jinjun;FAN Yuan;LAI Qinghui;XIE Lili(Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Institute of Structural Engineering and Disaster Prevention,Tongji University,Shanghai 200092,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第11期14-21,共8页
Journal of Vibration and Shock
基金
国家自然科学基金重点项目(U1939210)。
关键词
铁路梁桥
最不利设计地震动
输入地震动
地震反应
排序
Railway beam bridge
the most unfavorable design ground motion
input ground motions
seismic response
ground motion intensity measures
