摘要
为研究近断层地震下预制拼装桥墩桥梁结构的碰撞响应及影响碰撞的参数,基于OpenSees有限元分析软件,建立一座五跨预制拼装桥墩桥梁分析模型,选取8组近断层脉冲型地震动对桥梁进行非线性动力时程分析;探究了碰撞效应对桥梁地震响应的影响及节段数目、节段长度、初始预应力、接缝刚度等参数对桥梁碰撞效应的影响。结果表明:桥梁碰撞效应可以减小桥梁震时最大位移和震后残余位移,碰撞效应可以减小下部预制拼装桥墩地震中预应力筋的最大预应力、接缝最大竖向压力,但不能改变接缝水平剪力的大小;碰撞主要发生于桥梁中部伸缩缝处,中部伸缩缝碰撞力和碰撞次数均明显大于两侧边伸缩缝;增加预制拼装桥墩的节段数目可以减小桥梁的震时最大位移,但会增大桥梁的碰撞力和碰撞次数,其中6个节段时主梁中缝、左边缝和右边缝最大碰撞力比3个节段时分别增大约38.8%、36.5%和33.3%;初始预应力的大小对桥梁碰撞效应影响较小;引入的系数δ可以有效控制桥墩干接缝的刚度,δ增大时桥墩接缝刚度增大,接缝张开量减小,桥墩接缝耗能能力增强,桥梁碰撞力减小。
In order to study the pounding response and pounding parameters of bridge structure with precast segmental bridge piers under near-fault ground motions.Based on OpenSees finite element analysis software,an analysis model of five-span bridge structure with precast segmental bridge piers was established.Eight groups of near-fault pulse ground motions were selected to carry out non-linear dynamic time history analysis of the bridge.The pounding effect on the seismic response of the bridge and the number of segments,the length of segments,the initial prestress,joint stiffness and other parameters on the pounding effect of the bridge were explored.The results show that the pounding effect can reduce the maximum displacement and the residual displacement of the bridge,and the pounding response can reduce the maximum prestress of the prestressed bar and the maximum vertical pressure of the joint in the earthquake of the precast segmental bridge piers,but cannot change the horizontal shear force of the joint.The pounding mainly occurs at the expansion joint in the middle of the bridge.The pounding force and pounding times of the middle expansion joint are significantly bigger than those of the expansion joints on both sides.Increasing the number of pier segments can reduce the maximum displacement of the bridge,but it will increase the pounding force and pounding times of the bridge.Among which the maximum pounding force of the middle joint,the left joint and the right joint of the girder increases about 38.8%,36.5% and 33.3%,respectively,in six segments compared with three segments.The initial prestressed force has little influence on the pounding effect of the bridge.The introduced coefficient can effectively control the stiffness of the dry joint of the pier,when δ increases,the joint stiffness increases,the joint opening decreases,the joint energy dissipation capacity increases,and the pounding force of the bridge decreases.
作者
赵建锋
孟庆一
刘雪飞
ZHAO Jianfeng;MENG Qingyi;LIU Xuefei(School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China;The Fourth Construction Co.Ltd of China Construction Eighth Engineering Division,Qingdao 266100,China)
出处
《防灾减灾工程学报》
CSCD
北大核心
2022年第1期69-80,共12页
Journal of Disaster Prevention and Mitigation Engineering
基金
国家自然科学基金项目(51778314)资助。
关键词
桥梁抗震
预制拼装桥墩
桥梁结构
碰撞效应
动力时程分析
seismic resistance of bridges
precast segmental bridge pier
bridge structures
pounding effect
dynamic time history analysis
