钢筋混凝土柱-交错桁架结构抗震性能分析  

Pushover Analysis on the Seismic Performance of RC Column-Staggered Truss Structure

作　　者：郑琦 相瀛昌[1,2] 王宣鼎 刘界鹏 周绪红[1,2] Qi Zheng;Yingchang Xiang;Xuanding Wang;Jiepeng Liu;Xuhong Zhou(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area(Chongqing University),Ministry of Education,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]山地城镇建设与新技术教育部重点实验室(重庆大学),重庆400045

出　　处：《钢结构（中英文）》2020年第11期25-39,共15页Steel Construction（Chinese & English）

基　　金：国家自然科学基金项目(51890902)。

摘　　要：交错桁架结构体系产生于20世纪60年代中期,具有开间大、建筑布置自由、自重轻、施工速度快等优点。交错桁架结构整体受力性能好且自重较轻,其框架柱的内力一般较小,使得体系内钢柱的设计往往由长细比控制。中建科技有限公司设计开发的钢筋混凝土(RC)柱-交错桁架结构,采用预制RC柱替代传统钢柱,在保证结构性能与施工便利性的前提下,有效降低结构造价。以某实际工程为背景,利用MSC.MARC软件建立抗震设防烈度为7度(0.1g)的9层RC柱-交错桁架结构有限元模型,并采用倒三角分布加载模式对结构开展静力弹塑性分析。根据能力谱法求得结构的性能点状态,分别从楼层位移、层间位移角和构件屈服顺序三个方面分析了结构的抗震性能。在原有限元模型的基础上建立了3个局部斜腹杆失效的RC柱-交错桁架结构有限元模型,评估局部斜腹杆失效对结构抗震性能的影响。研究结果表明:1)RC柱-交错桁架结构具有抗侧刚度大的特点,多遇地震作用下的弹性层间位移角和罕遇地震作用下的弹塑性层间位移角都远小于JGJ/T 329—2015《交错桁架钢结构设计规程》限值,最大层间位移角分别出现在第3层与第2层;2)构件屈服最早出现在靠近外侧的交错桁架中下部的斜腹杆,随着地震作用的增大,内侧交错桁架斜腹杆也逐渐屈服;3)局部斜腹杆失效的结构与原结构的结构能力曲线基本重合,随着抗震设防水准的提高,顶点位移的差距由8%下降到3%;4)在多遇地震设防水准下,局部斜腹杆失效使对应轴线的最大层间位移角最多增加32.7%,在罕遇地震设防水准下最多增加17.8%,但弹性层间位移角和弹塑性层间位移角仍远小于规范限值;5)局部斜腹杆失效会使结构在罕遇地震设防水准下屈服构件数量增加(2~4根斜腹杆),但结构整体仍处于弹性状态。RC柱-交错桁架结构整体抗震性能良好,能够满足Stagger truss structure system was derived from the middle of 1960s,with the advantages of open space,free layout,light weight,and convenient construction.The internal force of the frame column in stagger truss system is generally small because of the good overall mechanical performance and light weight,so the design of the steel column in the structure is usually controlled by the slenderness ratio.Construction Technology Co.,Ltd.designed an RC column-staggered truss structure by replacing the conventional steel columns with precast RC columns.The application of the precast RC columns reduces the cost of the structure without reducing the quality and the convenient construction.A finite element model of a 9-story RC column-staggered truss structure in an area of 7-degree(0.1g)seismic fortification intensity was established by MSC.MARC software based on a practical project and the pushover analysis was conducted.According to the performance point of the structure,the seismic performance of the structure was analyzed in terms of the story drift,inter-story drift ratio,and member yielding sequence.Three models of removing partial diagonal web members were established based on the original model,and the failure effect of partial diagonal web members on seismic performance was analyzed.The results are as follows:1)The maximum inter-story drift ratio of the RC column-staggered truss structure under the action of frequent earthquakes and rare earthquakes is far less than the limit value of the Specification for Design of Staggered Steel Truss Framing Systems(JGJ/T 329-2015).The maximum inter-story drift ratio appeared at the third and second floors.2)The first yield diagonal web appeared in the of the middle and lower part of the stagger truss near the outside.With the increase of the seismic action,the diagonal web of the staggered truss on the inside also gradually yielded.3)The structural capacity curves of the structures with diagonal web failures are basically the same as those of the original structures.With the

关 键 词：钢筋混凝土柱-交错桁架结构 抗震性能 静力弹塑性分析 局部构件失效 

分 类 号：TU352.11[建筑科学—结构工程] TU375