在对比欧洲、美国、日本和中国规范的设防目标和地震作用的基础上,对钢框架结构的设计地震力、延性、侧向刚度和强度等开展系统地对比研究。结果表明,短周期结构按欧洲、美国和中国规范计算的侧向地震力分布相同,与按日本规范计算的亦十分接近;而中、长周期结构按欧洲规范计算的侧向地震力小于按其他规范计算的,尤其是结构的顶层;尽管各国规范规定的材料和构件延性要求差别不大,美国规范针对钢框架规定的地震力折减系数大于欧洲和日本规范的,而中国规范采用了与结构形式无关的较保守的折减系数,导致按中国规范设计的钢框架侧向刚度和强度基本上均比欧洲和美国规范的大20%~150%,但由于日本规范采用的弹性反应谱远大于其他规范,折减后设计地震力也更大,使得按日本规范设计的钢框架侧向刚度和强度比中国规范的还大;总体上,按欧洲规范设计的钢框架侧向刚度和强度与按美国规范设计的结果相当。
Based on the comparison of fortification target and seismic action in seismic codes of Europe,the United States,Japan and China,seismic design forces,ductility requirements,lateral stiffness and strength of steel frame structures were compared systematically.The results show that for short-period buildings,lateral seismic force distributions in Eurocode,the United States and Chinese codes are the same and very close to that in Japanese code,while for intermediate-period and long-period buildings,the United States,Japanese and Chinese codes always specify larger story shear force than Eurocode at any story,with the largest difference at the top story.Although local ductility requirements are quite similar,the United States code specifies higher reduction factors than Eurocode and Japanese code,while Chinese code stipulates a constant reduction factor with a relatively small value regardless of the ductility level of structures.As a result of such over-conservatism,steel frames designed by Chinese code exhibit 20% to 150% larger lateral stiffness and strength than Eurocode and the United States code in most cases,while the significant even larger lateral stiffness and strength predicted by Japanese code than that by Chinese code is mainly due to the larger reduced seismic design forces derived from the larger elastic response spectrum.Generally,Eurocode designed steel moment frames exhibit comparable lateral stiffness and strength with the United States code.