多层大悬挑钢结构体系静力与抗震性能设计

Study on static and seismic performance of multi-floor steel cantilevered structure

内蒙古伊旗全民健身体育中心主体结构采用下部收进、上部多层大悬挑结构,体系的竖向刚度明显不规则,使得结构体系在静力及罕遇地震作用下弹塑性性能成为结构体系安全控制的关键因素。首先对主体结构进行静力弹塑性分析,选取性能目标对不同方案进行对比,优化选择了带外斜交网格结构的多层大悬挑结构体系。随后分别采用振型分解反应谱法、弹性动力时程分析法和弹塑性动力时程分析方法对该结构体系进行了抗震性能分析,重点对结构的不规则性、结构安全性、大震下弹塑性性能及抗倒塌性能进行分析。分析表明,按选定性能目标优化得到的结构体系经济合理,实现了多层大悬挑结构在静力及地震作用下性能安全的设计目标。

The narrower on lower floors and the wider on upper floors structure is used in the National Fitness Center,in Ejin Horo Banner,Inner Mongolia,which has the characteristic of extreme vertical stiffness irregularity.The elasto-plastic performance in the condition of static stability limit state becomes the key factors of the security of the structure.First,the performance of the main structure in the condition of static loading was analyzed adopting the performance target put forward in this paper.The choice of the multi-floor structure with the huge grid as the best scheme was made among many schemes.Then the seismic performance studies were conducted by response spectrum analysis,elastic dynamic time-history analysis and elasto-plastic dynamic time-history analysis respectively.The key part of the analysis is the irregularity of the structure,the security at the end of cantilever and the elasto-plastic performance in the condition of major earthquake.Analysis shows that the structural scheme selected based on the performance target put forward in this paper is economic and reasonable,and the static and seismic performance objectives for design are realized.