摘要
针对防屈曲支撑-混凝土框架(RC-BRBF)体系中防屈曲支撑(BRB)对相连柱产生附加变轴力影响,提出了RC框架柱设计方法。该方法首先通过等价轴压比指标获得RC柱设计轴压比限值,保证了一级、二级以及三、四级框架柱极限侧移水平分别达到2.7%、2.4%以及2.1%;然后通过体系延性水平获得柱位移延性指标,保证其延性性能。研究表明,RC柱设计轴压比限值与等价设计轴压比水平、构件受等效重力与地震作用的轴力标准值之比有关;改进后的设计方法能够有效考虑BRB对相连柱附加变轴力影响,并保证了变轴压比下柱的极限侧移水平。算例分析结果表明,该方法通过优化柱截面提高了体系经济性,同时保证体系满足"三水准"设防目标,RC柱设计轴压比限值的设定是合理的。
An improved design procedure for reinforced-concrete(RC)columns in conjunction with bucklingrestrained braces(BRBs)in RC-BRBF was developed in this paper for solving the variable axial loading problem induced by BRBs.The proposed method provides a limit value of axial compression ratio for RC columns based on the equivalent axial compression ratio in order to ensure the ultimate lateral displacement capacity of the primary,the secondary,the third and the fourth level of RC columns could reach 2.7%,2.4%and 2.1%,and provides a recommended ductility factor for RC columns based on the structural ductility capacity in order to achieve satisfactory ductility performance.It is shown that the limit value of axial compression ratio depends on the ultimate drift capacity as expressed by the equivalent axial compression ratio,and the ratio of the characteristic axial forces of the columns under the equivalent gravity and seismic actions,respectively.The improved method could effectively account for the influence of additional variable axial loads on the RC columns connecting to BRB,and ensure that RC columns could reach the limitation of ultimate lateral displacement capacity.The analysis results also reveal that the system economy could be enhanced though optimizing the section dimensions of RC column by the proposed method,and the RCBRBFs meet‘three seismic fortification levels’.Besides,the limitation of axial compression ratio factor is rational.
作者
许国山
徐小童
王贞
XU Guoshan;XU Xiaotong;WANG Zhen(Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology,Harbin 150090,China;Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,Harbin Institute of Technology,Harbin 150090,China;School of Civil Engineering,Harbin Institute of Technology,Harbin 150090,China;China Institute of Building Standard Design&Research,Beijing 100048,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2020年第3期105-115,共11页
Journal of Building Structures
基金
国家重点研发计划(2017YFC0703605)
国家自然科学基金项目(51978213,51778190,51308159).
关键词
RC框架
防屈曲支撑
设计方法
变轴压比
设计轴压比限值
RC frame
buckling-restrained brace
design method
variable axial compression ratio
limit value of axial compression ratio
