摘要
历史地震表明强余震会进一步增大结构的破坏程度甚至使其倒塌,但是我国乃至世界上的所有抗震设计规范均只考虑主震作用而没有直接考虑余震影响。为提出能有效考虑余震影响的抗震设计方法,文章基于主余震设计谱和主震设计谱共设计了12个钢筋混凝土(RC)框架结构。选取50条实际主余震地震动对所有结构进行增量动力分析进而得到结构倒塌易损性,对比分析了主余震、主震影响区域结构的倒塌储备系数CMR,发现仅采用设计谱进行弹性设计会使得主余震影响区域结构的CMR会小于主震影响区域结构。为实现主余震、主震影响区域结构的倒塌储备等效,首先给出了以基本周期T_(1)为变量的S_(a, 50%collapse)预测公式,然后推导了结构倒塌储备等效方程,并结合设计谱进行数值求解,最后给出了倒塌储备等效条件下以主震影响区域结构基本周期T_(1,M)为变量的主余震影响区域结构基本周期T_(1,A)预测公式,综合使用该预测公式和主余震设计谱可以实现主余震、主震影响区域结构的倒塌储备等效。
Historical earthquakes have confirmed that aftershocks would increase the damage of structures and even make them collapse, but all the seismic design codes in the world cannot consider the effects of aftershocks directly.A total of 12 reinforced concrete(RC) frame structures were designed based on mainshock-aftershock design spectrum and mainshock design spectrum.The collapse vulnerability of RC frame structures was studied with 50 as-recorded manishock-aftershock ground motions.The collapse margin ratio CMR of mainshock-aftershock affected and mainshock affected structures was compared and analyzed.It was found that the CMR of mainshock-aftershock affected structures was smaller than that of mainshock affected structures.In order to realize the collapse margin equivalence of structures, the prediction equation of S_(a, 50% collapse) is firstly proposed with basic period T_(1) as variable.Then collapse margin equivalent equation is derived, and it is numerically solved with design spectrum.The prediction equation of T_(1,A) is lastly proposed with T_(1,M) as variable under the collapse margin equivalent condition.The collapse margin equivalence of mainshock-aftershock affected and mainshock affected structures can be realized by comprehensively using the prediction formula and mainshock-aftershock design spectrum.
作者
温卫平
籍多发
虞亦琦
翟长海
Wen Weiping;Ji Duofa;Yu Yiqi;Zhai Changhai(Key Laboratory of Structures Dynamic Behavior and Control of the Ministry of Education,Harbin Institute of Technology,Harbin 150090,China;Key Laboratory of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology,Harbin Institute of Technology,Harbin 150090,China)
出处
《土木工程学报》
EI
CSCD
北大核心
2021年第2期43-49,共7页
China Civil Engineering Journal
基金
国家自然科学基金(51708161,51825801)
中国地震局工程力学研究所基本科业务费专项资助(2017D09)。
关键词
余震
钢筋混凝土框架
倒塌储备
抗震设计方法
aftershock
reinforced concrete frame
collapse margin
seismic design method
