【摘要】 板件宽厚比是表征钢结构延性的重要方面,也是控制耗钢量的关键指标。在保证结构安全可靠的前提下,合理控制抗震钢结构的板件宽厚比,对降低耗钢量,提高钢结构的经济性具有十分重要的工程实践意义。简要讨论抗震钢结构"高延性,低弹性承载力"和"低延性,高弹性承载力"两种抗震设计思路。在对比我国抗震规范与欧洲、美国、日本规范的抗震钢框架板件宽厚比限值的基础上,以底部剪力基本等价为前提,架通我国抗震规范第一水准设防地震作用FEK与欧洲EC8、日本BCJ规范的地震作用、板件宽厚比限值之间的联系桥梁。进而,提出以地震作用效应组合分级对应钢框架受力状态的方式确定框架构件截面等级,即按钢框架梁柱(抗侧力结构)的受力情况选择其相应的截面板件宽厚比。该方法可与现行抗震规范的体系配套,并使板件宽厚比限值的规定趋于合理,以供工程设计、抗震规范修订时参考。同时,指出目前一些抗震规程以"小震"作用界定板件宽厚比的做法偏于不安全,应及时纠正。更多还原

【Abstract】 The width-thickness ratio of steel members is a key factor reflecting structural ductility and governing steel consu mptions. Under the precondition that structure safety is ensured, proper cont rol of width-thickness ratios for earthquake-resistant steel structure s h as a considerable directing meaning for steel consumption decreasing and economi cal efficiency improvement in engineering practices. It is briefly discussed the seismic design philosophy with two paths, i.e ., "high ductility with low elastic strength" and "low ductility with high e lastic strength". Limiting width-thickness ratios for earthquake-resistant steel frames stipulated by the Chinese seismic code are compared with those of European, US and Japanese codes, and a relationship of t he Chinese Level-1 seismic action F EK with seismic actions of EC8 and BCJ codes for width-thickness ratio classification is established based on the equiv al ence of base shears. Furthermore, a procedure is proposed to classify cross-sec tions by the loading behavior of steel frames corresponding to different seismic acting effect combinations, i.e., to choose width-thickness ratios according to the actual loading behavior of beams and columns (lateral force resisting s tructures) under seismic actions. The method is compatible with the Chinese se ismic code system and is more appropriate for the width-thickness ratio requirem ent.It may be a reference for project design and revision of seismic code s. Also, it is pointed out that the method by some seismic specifications usin g a minor earthquake action for determining limiting width-thickness ratios is o n an excessively dangerous side and should be prevented.更多还原