长周期地震动作用特性及其对RC柱抗震性能的影响研究  

Study on long-period ground motion action characteristics and its effect on seismic behavior of RC columns

作　　者：张佳伟 王博 刘扬 王智鹏 杨柯 李哲 刘伯权[1] ZHANG Jiawei;WANG Bo;LIU Yang;WANG Zhipeng;YANG Ke;LI Zhe;LIU Boquan(School of Civil Engineering,Chang’an University,Xi’an 710061,China)

机构地区：[1]长安大学建筑工程学院,陕西西安710061

出　　处：《地震工程与工程振动》2023年第5期191-203,共13页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金项目(51978076,51708037);中央高校基本科研业务费资助项目(300102283202);陕西省自然科学基金项目(2023-JC-YB-411)。

摘　　要：长周期地震动作用下结构的位移响应呈现多次大位移往复、长持时的特点,体现了其区别于普通地震动的特殊作用特性。长周期地震动对结构的影响研究关键在于揭示长周期地震动作用特性对结构构件抗震性能的影响机理。首先,基于雨流计数法对长周期地震动和普通地震动作用下单自由度体系的弹塑性位移响应进行循环统计分析,阐明了长周期地震动的作用特性,并以此构建了考虑长周期地震动作用特性的拟静力加载制度。其次,通过对不同设计参数的RC柱进行传统加载制度和考虑长周期地震动作用特性加载制度作用下的低周往复加载,分析其抗震性能差异,揭示了长周期地震动作用特性对RC柱的影响。研究结果表明:长周期地震动表现为地震动强度需求小,结构弹塑性位移循环总数多,且以小弹塑性位移循环为主的地震动作用特性。长周期地震动作用特性显著影响RC柱的强度与刚度退化规律,且对低等级混凝土、高轴压比、高纵筋配筋率和高体积配箍率构件的刚度退化影响更为显著。The seismic response of structures under long-period ground motions(LPGM)is obviously different from that of ordinary ground motions(OGM),which reflects the special action characteristics of LPGM.Investigating the influence mechanism of action characteristics on seismic performance of the structural component is the key to revealing the influence mechanism of LPGM on the long-period structures.In this paper,the elastic-plastic displacement cycles of SDOF system under the LPGM and OGM were calculated and counted,and the action characteristics of LPGM were analyzed.Based on this,the quasi-static loading protocol considering the characteristics of LPGM was established.Then,through comparing the differences in seismic performance of RC columns under traditional loading protocols and loading protocols considering the action characteristics of LPGM,the influence of LPGM on the seismic performance of RC columns was revealed.The results show that the LPGM are characterized by low ground motion intensity,large number of elastic-plastic displacement cycles of structures,and mainly small elastic-plastic displacement cycles.Compared with the traditional loading protocols,the degradation degree of RC column strength and stiffness is significant under the loading protocol considering the characteristics of LPGM,and the degradation path is obviously different from the traditional loading protocols.The action characteristics of LPGM more significantly influenced the stiffness degradation of members with low concrete grade,high axial compression ratio,high longitudinal reinforcement ratio and high transverse reinforcement ratio.

关 键 词：长周期地震动 作用特性 加载制度 RC柱 抗震性能 

分 类 号：TU352.11[建筑科学—结构工程]