不同连接构造的预制拼装钢管混凝土桥墩数值模拟与地震响应特点  

Numerical simulation and seismic response characteristics of prefabricated assembled concrete filled steel tube columns with different connection constructions

作　　者：陈挺地 王胜斌[2] 冯克岩 李建中[1] CHEN Tingdi;WANG Shengbin;FENG Keyan;LI Jianzhong(State Key Lab for Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China;Anhui Transport Consulting&Design Institute Co.,Ltd.,Hefei 231262,China;Tianjin Municipal Engineering Design&Research Institute Co.,Ltd.,Tianjin 300392,China)

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092 [2]安徽省交通规划设计研究总院股份有限公司,合肥231262 [3]天津市政工程设计研究总院有限公司,天津300392

出　　处：《振动与冲击》2024年第7期134-143,共10页Journal of Vibration and Shock

基　　金：天津市交通运输科技发展计划项目(2021-01);自然基金重点项目(51838010)。

摘　　要：无黏结预应力节段拼装钢管混凝土桥墩主要包括承插连接与混合连接两种承台连接方式。为比较两种不同连接构造下桥墩的地震响应特点,采用OpenSees软件分别建立了桥墩有限元模型,其中,承插连接钢管混凝土桥墩模型能够考虑插入承台部分钢管与周围混凝土的黏结滑移、钢管局部屈曲以及屈曲后撕裂等过程,而混合连接钢管混凝土桥墩模型能够再现出接缝的摇摆行为;并通过与相关拟静力试验数据结果进行对比,验证了两种数值模型的有效性;随后,以一座4跨连续梁桥为背景,分别研究了采用混合连接、无预应力承插连接和预应力承插连接桥墩桥梁结构在地震作用时的响应特点。结果表明:两种承插连接桥墩的墩底钢管在地震动峰值加速度(peak ground acceleration,PGA)约0.4 g时发生屈曲,并伴随水平刚度下降和残余位移增大,且配置无黏结预应力的承插连接桥墩钢管屈曲引起的损伤程度更大,随着地震动输入进一步增大,预应力为桥墩提供的自复位能力逐步增加,在PGA=0.6 g时,预应力承插连接桥墩的残余位移仅为无预应力桥墩的62%。此外,配置混合连接桥墩的桥梁在地震作用下损伤较小,残余漂移比小于0.2%,比承插连接桥墩更优的自复位能力。Non-bonded prestressed segmental assembled concrete filled steel tube columns mainly include two types of platform connection methods of socket connection(SC)and hybrid connection(HC).Here,to compare seismic response characteristics of bridge piers under two different connection constructions,the software OpenSees was used to establish bridge pier finite element models.In them,the SC model could consider bonding slip between part of steel tube inserting platform and surrounding concrete,local buckling of steel tube and post-buckling tearing process,while the HC model could reproduce swinging behavior of joints.Through comparing finite element simulation results with relevant quasi-static test data results,the effectiveness of 2 numerical models was verified.Then,taking a 4-span continuous beam bridge as the background,seismic response characteristics of bridge structure and piers using hybrid connections,non-prestressed socket connections and prestressed socket connections under earthquake action were studied.The results showed that steel tubes at pier bottom of two types of socket connected bridge piers have buckling when peak ground acceleration(PGA)is about 0.4 g accompanied by decrease in horizontal stiffness and increase in residual displacement;damage degree caused by buckling of steel tubes in socket connected bridge piers with unbonded prestressing is larger;with increase in ground motion input,the self-resetting ability provided by prestressing for bridge piers gradually increases;when PGA=0.6 g,residual displacement of prestressed socket connected bridge piers is only 62%of that of non-prestressed bridge piers;in addition,bridges equipped with hybrid connection piers have less damage under seismic action,their residual drift ratio is less than 0.2%,they have better self-resetting ability than those equipped with socket connection piers.

关 键 词：桥梁工程 钢管混凝土(CFT)桥墩 承插连接(SC) 混合连接(HC) 有限元模型 地震响应 

分 类 号：U443.22[建筑科学—桥梁与隧道工程] U442.55[交通运输工程—道路与铁道工程]