钢柱外包式柱脚抗震设计问题

柱脚是钢结构中上部主体结构与基础连接的重要节点,外包式柱脚常用于重钢结构厂房,其计算假定为柱脚刚接,在地震作用效应时传递弯矩至基础。GB50011-2010《建筑抗震设计规范》明确规定了这种柱脚设计时的极限承载力计算方法。构造要求的柱截面面积条件在节点弹塑性承载力设计中起控制作用的情况,在实际设计过程中常出现。从钢结构框架柱的截面确定方法入手,对不同规范规定的长细比限值进行比较,用极限弹塑性设计抗弯承载力要求和多遇地震抗弯承载力要求来分析比较外包式柱脚的设计,满足柱脚配筋设计的经济性和合理的计算要求。

SEMI-EMBEDDED STEEL COLUMN BASE DESIGN ISSUE UNDER SEISMIC CONDITION

The column base is an important node in the upper part of the theme in the steel structure and foundation connections, semi-embedded steel column base is commonly used in multi-high-rise steel frames, the calculation assumes that the column base is rigid, seismic effect passes moment to the foundation. Code for Seismic Design of Buildings (GB 50011-2010) specifies the calculation method of the ultimate bearing capacity for this kind of column base. In the actual design process, column section area takes the control effect in the column base node elastic-plastic bearing capacity design. In this paper, from the method to determine the column cross-section of the steel structure framework, slenderness ratios in different codes were compared and then the requirements of the limit of elastic-plastic flexural capacity requirements and the flexural capacity to analyze the semi-embedded column base design were analysed, which could meet economic and reasonable requirements of the column base reinforcement design.