- 摘 要
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(上海长福工程结构设计事务所, 上海 200031)
[摘要]推导了底部剪力系数Cs的通用表达式,绘制了Cs-T关系曲线,结果表明Cs随基本周期变长而快速下降。不满足最小底部剪力系数Cmins的需求并不意味结构方案和布置不合理。按当前的抗震理论,底部剪力是结构承受地震作用大小的宏观指标。当结构的基本周期超过某一个临界周期时,合理、简单、有效的方法是按比例放大设计地震作用使Cs≥Cmins,而不是增大刚度、缩短周期。另外,笔者认为《建筑抗震设计规范》(GB 50011—2010)规定的Cmins限值是合理的,应予以执行。然而,当使用基于性能的方法进行抗震设计时,可予以放松。
[关键词]长周期; 超高层建筑; 最小底部剪力系数; 强度控制; 刚度控制
中图分类号:TU398.2 文献标识码:A 文章编号:1002-848X(2014)10-0001-06
Minimum base shear coefficient for long period super high-rise buildings
Fu Changsheng, Zhang Xiaoyong, Zhou Lilang
(Shanghai ChinaFu Structural Design Inc., Shanghai 200031, China)
Abstract: The general expression was given for the base shear coefficient Cs and Cs-T curves were also plotted. Results show that Cs will rapidly reduce with the longer period. It does not mean unreasonable structural design and layout that the calculated Csis less than the minimum base shear coefficient Cmins. The base shear is a comprehensive index of magnitude of the seismic force acting on the buildings based on the current seismic theory. For the case that the fundamental period of a structure is longer than one certain critical period, amplification of the input seismic action in scale may be reasonable, simple and effective method to meet the demand of Cs≥Cmins, instead of increasing the structural stiffness and shortening the period. Besides, the minimum limitation Cminsis reasonable for the base shear stipulated in Code for seismic design of buildings(GB 50011—2010), which should be implemented. However, if the performancebased method is used for the seismic design, the limitation could be relaxed.
Keywords: long period; super high-rise building; minimum base shear coefficient; strengthen control; stiffness control
作者简介:扶长生,教授级高级工程师,Email:cfstruct@vip.sina.com。
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