摘要
最小地震剪力系数是超高层建筑抗震设计中的关键控制因素。首先对中美两国典型抗震规范或规程中有关最小地震剪力系数(最小基底剪力)的相关规定进行了对比分析。借鉴美国规范中最小基底剪力的处理方法,以位于我国设防烈度7度区的一超高层建筑为例,采用两种不同的设计地震剪力取值方法,按照8度地震设防烈度设计了两个不同的结构模型。通过弹塑性时程分析,比较了两个模型在罕遇地震作用下的性能差异,分析了长周期地震动对两个模型抗震性能的影响,并对比了两个模型抗地震倒塌能力的差异。分析结果表明:通过提高楼层设计剪力来满足最小地震剪力系数的方案与提高结构刚度的方案相比,其抗罕遇地震的性能基本相当,而抗地震倒塌能力更好,设计难度和建造成本会更低。
The minimum shear force coefficient is the key issue in seismic design of super-tall buildings. Therefore, the requirements on the minimum base shear force in typical Chinese and U. S. seismic design codes and specifications were compared. Then based on a super-tall building located in 7-degree seismic fortification region of China,two building models with different design base shear forces were designed according to 8-degree fortification region in the Chinese codes and the alternative method proposed in the U. S. specifications,respectively. With a large number of nonlinear time history analysis,the seismic performances of these two buildings under the severe earthquake were comparatively discussed,as well as the influence of long-period ground motions on the seismic performance. Besides, the collapse margin ratio of these two buildings were compared subjected to a given ground motion. The analytical results indicate that Model B,whose design base shear force is adjusted to meet the acceptance limit of the minimum base shear force,has similar seismic performance to Model A,whose structural stiffness is adjusted to meet the acceptance limit of the minimum base shear force. In addition,Model B even performs a higher collapse margin than that of Model A with less difficulty and lower cost to design and construct.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2014年第5期88-95,共8页
Journal of Building Structures
基金
国家自然科学基金项目(51222804
51261120377)
北京市自然科学基金项目(8142024)
霍英东教育基金项目(131071)
关键词
超高层建筑
长周期结构
最小地震剪力系数
弹塑性分析
抗震性能
倒塌分析
刚度
super-tall building
long-period structure
minimum base shear force
elasto-plastic analysis
seismic performance
collapse analysis
structural stiffness
