【摘要】 我国地震灾难多发,其造成的人员伤亡和经济损失居世界之首。汶川地震震害表明依据不同时期抗震规范建造的结构抗震能力差异较大,其中建于1989年之前的结构抗震能力普遍偏弱。以此为基础,首先介绍抗震规范的发展,总结不同时期规范的差异性;然后针对既有结构中延性较低的钢筋混凝土框架结构,在OpenSees中采用IDA方法重点分析两类具有相同构件尺寸和配筋率但延性不同的结构的抗震性能,进而明确低延性结构的抗震薄弱环节。分析结果表明两类结构在同等地震作用下响应差别较大。在大震作用下,低延性结构易于发生脆性破坏,抗震性能较弱,尤其是抗倒塌能力远弱于新建结构。因此需要重视这类结构的分析方法和震前加固措施,以减少地震灾害造成的损失。更多还原

【Abstract】 Frequent earthquakes strike China,leading the casualties and economic losses the highest level in the world.As observed from Wenchuan earthquake reconnaissance,it can be concluded that structures built according to different levels of seismic codes have different seismic capabilities,and those built before the year 1989 have insufficient capability.So in this paper,the development of Chinese Code for Seismic Design of Buildings is introduced,and then some differences between codes are summarized.Finally two R.C.frame structures with the same dimension and reinforcement ratio but different ductilities are modeled in OpenSees,and in order to obtain the weakness of seismic performance for the low-ductile one,their seismic performance are analyzed based on IDA method.Based on the previous research,the paper concludes that the performances of the two structures are significantly different under different waves.Seismic capability,especially the collapse-resistance capacity of the low-ductile one is much weaker than the newly-built one under severe earthquake.To reduce losses caused by earthquakes,we should pay more attention to developing the modeling methods and reinforcement measures for low-ductile structures.更多还原