【摘要】 简述了中美两国抗震设计规范中有关地震波选择的相关条文,列举了工程实践中常用的选波方法,并对选出的地震波反应谱特性进行了比较。中美两国规范中建议的选波方法均要求选择能与规范的设计反应谱相一致的地震波,不同之处为中国规范是将地震波峰值加速度调幅至规范规定值,而美国规范是将某一周期范围内地震波反应谱调幅至与设计反应谱接近,调幅后的地震波峰值加速度无明显规律。按照中美两国抗震设计规范分别设计了两栋相似框架-核心筒结构,建立了两结构的弹塑性分析模型。根据中国规范建议方法选择出7组地震波,进行弹塑性时程分析。分析结果表明:在相应于中国8度罕遇地震的多组地震波作用下,中美两国规范设计方案在地震作用初期地震响应基本一致,在后期由于结构配筋形式与配筋数量等差异,结构损伤程度不同;按中国规范设计方案的最大层间位移角为按美国规范设计方案的1.03~1.17倍,连梁最大塑性变形为按美国规范设计方案的0.67~0.98倍,剪力墙应变沿层高的分布接近,美国规范设计结构纵筋的屈服应变是中国规范设计方案的1.2倍,按中国规范设计方案的剪力墙损伤程度重于按美国规范设计的剪力墙。更多还原

【Abstract】 Recommended criteria about earthquake ground motion selection in Chinese and American seismic design codes were introduced and typical selection methods in engineering practice were listed. The response spectrum features of ground motion selected and modified by different methods were compared. The study indicates that the methods suggested in Chinese and American codes both aim to select ground motion whose spectrum is consistent with the prescribed design response spectrum. The difference is that Chinese method scales the peak ground acceleration( APG) of a record to a prescribed value,but American method modifies the record to provide the best match to the spectral shape of the design response spectrum over a period range of interest,with irregular APG of scaled ground motions. The elasto-plastic responses of two similar frame-core wall structures designed in accordance with Chinese and American design codes respectively are studied in this paper,where seven pairs of ground motions were selected and modified by Chinese suggested methods as the input ground motion records. The elasto-plastic time history analysis results illustrate that under the rare earthquake action of 8 intensity,the seismic responses of Chinese design structure and American design structure are nearly the same in the beginning,while the damages of two structures become different on account of the reinforcement layout and amount variations in the later period; the maximum drift ratio of Chinese design project is 1. 03 ~ 1. 17 times that of American design project,the maximum plastic rotation of coupling beams of Chinese design project is 0. 67 ~ 0. 98 times that of American design project,the strain distribution along structure height of shear walls is similar,but the shear wall damage of Chinese design project is severer than that of American design project because the reinforcement yield stain of American design project is 1. 2 times that of Chinese design project.更多还原