摘要
现行抗震设计规范中关于地震动持时的规定不明确,而持时对在罕遇地震作用下结构的非线性地震响应及抗倒塌能力评估影响较大。基于规范反应谱拟合地震动持时分别为20、40、60 s的人工地震波各10条,利用Open Sees分析软件建立了一钢筋混凝土框架-填充墙结构教学楼的三维空间模型,以这些人工地震动为输入进行增量动力分析,得到对应于不同持时记录的结构平均增量动力分析曲线,进而分析其最大顶点位移、最大残余顶点位移和最大残余层间位移角与各地震动记录有效持时之间的相关性,给出了结构在不同持时记录以其基本周期对应的谱加速度Sa(T1)表示的抗倒塌能力,及其与有效持时的关系和不同持时与不同Sa(T1)相应的倒塌概率。分析结果表明:当地震动强度水平相同时,较长持时的地震动记录可使结构产生较大的层间位移角和较高的倒塌概率,并且随着有效持时的增加,结构的抗倒塌能力呈降低趋势,而位移需求并不能完全说明持时对结构倒塌发生的影响。
The requirement for ground motion duration is not clear in current seismic design code.And ground motion duration has great influence on nonlinear seismic responses and evaluation for collapse resistance capacity under severe earthquake. First,10 artificial ground motion records with 20s, 40 s and 60 s duration were generated based on code response spectrum respectively. The three-dimensional model of an infilled RC frame teaching building was built by OpenSees, and incremental dynamic analysis （IDA） was carried out on the model under these artificial ground motion records. Furthermore, the geometric mean IDA curves for all records with different duration were obtained. And correlation of the maximum roof displacement, maximum residual roof displacement and maximum residual inter-story drift ratio with the significant duration was investigated. Finally, the collapse resistance capacity in terms of Sa（T1） , spectral acceleration at the fundamental period of the structure, and its correlation with significant duration of all ground motion records with different duration and collapse probability under different Sa（T1） were obtained. The analytical results show that records with longer duration can induce larger inter-story drift ratio and higher collapse probability for the structure when intensity levels are similar. With the increase of the significant duration, structural collapse resistance capacity tends to decrease. It seems that the drift demand is not a good indicator for the influence of duration on collapse when the structure is subjected to ground motion with long duration.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2016年第7期121-126,共6页
Journal of Building Structures
基金
国家自然科学基金项目(51268036)
甘肃省科技支撑计划资助(1204FKCA126)
教育部长江学者和创新团队发展计划(IRT13068)
关键词
RC框架-填充墙结构
有效持时
人工地震动
残余位移
最大层间位移角
抗倒塌能力
infilled RC frame structure
significant duration
artificial ground motion
residual displacement
maximum inter-story drift ratio
collapse resistance capacity
