近场脉冲型地震作用下附加支撑双柱式摇摆桥墩的抗震性能研究  

STUDY ON SEISMIC PERFORMANCE OF DOUBLE-COLUMN ROCKING BENTS WITH ADDITIONAL BRACES UNDER NEAR-FIELD PULSE GROUND MOTIONS

作　　者：董慧慧[1] 古智钧 杜修力[1] 苏灿 DONG Hui-hui;GU Zhi-jun;DU Xiu-li;SU Can(Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124

出　　处：《工程力学》2024年第5期13-25,共13页Engineering Mechanics

基　　金：国家重点研发计划项目(2018YFC1504306);国家自然科学基金项目(51838010,51908325)。

摘　　要：为了解决摇摆桥墩承载力和耗能能力不足的问题,该文提出一种附加人字形支撑的双柱式摇摆桥墩结构,支撑为纯耗能支撑或自复位耗能支撑,支撑通过连接装置安装在双柱式摇摆桥墩的盖梁和承台之间。为了研究新型附加人字形支撑双柱式摇摆桥墩的抗震性能,对其进行拟静力分析,将双柱式现浇桥墩和双柱式纯摇摆桥墩作为对比模型,研究附加纯耗能支撑和自复位耗能支撑双柱式摇摆桥墩的滞回性能;分别对这四种桥墩结构进行动力时程分析,探究这四种桥墩在近场对称脉冲、近场非对称脉冲和远场无脉冲地震动作用下的动力响应。研究结果表明:附加支撑的双柱式摇摆桥墩中的墩柱仍具有摇摆机制,可有效避免墩身出现塑性铰发生严重的损伤破坏,同时附加的支撑可以显著提高桥墩的承载能力和耗能能力,有效降低桥墩结构的位移响应,特别是自复位耗能支撑还可额外为桥墩提供自恢复力,有效提高结构的抗震性能。To solve the issues of insufficient bearing and energy dissipation capacities of rocking bents,a double-column rocking bent structure with braces placed in chevron arrangement is developed in this study.The braces are pure energy dissipation ones or self-centering energy dissipation ones,installed between the cap beam and the foundation of the double-column rocking bent by connecting devices.To study the seismic performance of the double-column rocking bent structure with braces developed,its quasi-static analysis is carried out firstly.Taking the double-column cast-in-situ bent and the double-column rocking bent as the comparative model,the hysteretic behavior of the double-column rocking bent with additional braces are investigated;The dynamic time history analysis of these bents is carried out to explore the dynamic responses of the structures due to the near-field symmetrical pulse,to near-field asymmetrical pulse and to far-field non pulse ground motions.These results show that:the double-column rocking bent with additional braces still behaviors the rocking mechanism,which can effectively avoid the serious damage to the plastic hinge of column;at the same time,the additional braces can significantly improve the bearing capacity and energy dissipation capacity of the bent and,reduce the displacement response of the bent;especially,the self-centering energy dissipation braces can also provide additional self-centering force for the bent,which can effectively improve the seismic performance of the bent.

关 键 词：桥梁抗震 双柱式摇摆桥墩 耗能支撑或自复位耗能支撑 抗震性能 近场脉冲地震动 

分 类 号：U443.22[建筑科学—桥梁与隧道工程]