摘要
楼层最小地震剪力系数是建筑抗震设计中的重要控制指标之一。对现行规范规定的最小地震剪力系数限值与场地特征周期无关的不合理性进行了分析,这也是导致Ⅰ、Ⅱ类场地上的长周期结构基底剪力系数难以满足规范限值的主要原因。分析了影响基底剪力系数的因素,发现基底剪力系数受到结构质量和刚度的分布、地震烈度、场地特征周期、结构阻尼比以及设计反应谱形状的影响。提出了基于场地特征周期的最小地震剪力系数限值,在场地条件较好时可放松规范限值,这样使长周期结构的抗震设计更容易满足地震剪力系数的要求,更为经济合理。通过一个算例验证了文中提出的基于场地特征周期的最小地震剪力系数限值的合理性。
The minimum seismic shear coefficient is one of the important control indexes in the seismic design of buildings. The irrationality of the independency of the minimum seismic shear coefficient limit on the characteristic period of the site in the Chinese seismic design code was analyzed,which is also the main reason why it is difficult for the base shear coefficients of long-period structures in the site with class Ⅰ or Ⅱ to satisfy the code limit. The factors affecting the base shear coefficient were analyzed. It is found that the base shear coefficient depends on the factors such as the distribution of the mass and the stiffness,the seismic intensity,the characteristic period of the site,the damping ratio and the shape of the design spectrum. A new minimum seismic shear coefficient limit based on the characteristic period of the site was proposed,which lowers the code limit when the site soil condition is good,so that the requirement on the seismic shear coefficient for the long-period structure in the seismic design can be met more easily and the design would be more economical. The new limit for the minimum seismic shear coefficient proposed in this study was verified by a case study.
作者
蒋欢军
段延锋
王逸珂
JIANG Huanjun DUAN Yanfeng WANG Yike(State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China Research Institute of Structural Engineering and Disaster Reduction, Tongji University, Shanghai 200092, China China Overseas Property Project Management Co., Ltd, Shanghai 200122, China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2017年第3期39-45,共7页
Journal of Building Structures
基金
国家自然科学基金项目(51478354)
关键词
最小地震剪力系数
场地特征周期
设计反应谱
抗震设计
minimum seismic shear coefficient
characteristic period of site
design response spectrum
seismic design
