主余震序列型地震动下典型村镇砌体结构抗震性能分析

Seismic performance analysis of masonry structure in typical villages and towns under mainshock-aftershock sequence ground motion

强震过后通常会发生多次余震,结构在主余震序列作用下的震害也往往比单独主震作用时更为严重。我国村镇砌体结构量大面广,历史震害严重。本文针对2005年九江-瑞昌地震中某典型砌体结构,在前期研究的基础上,基于主余震统计关系构造主余震序列型地震,对其进行弹塑性有限元分析,对比分析单一主震和主余震序列型地震动下结构的震害特征、损伤耗能和位移反应的差异,以明确余震对结构抗震性能的影响。结果表明:余震会对主震中受损结构造成更严重的破坏,尤其会加剧底部楼层的损伤程度;余震损伤与主震损伤和余震强度有关,当结构主震损伤及余震强度较大时,余震对结构损伤的影响更为显著。

Many aftershocks usually occur after a strong earthquake and the damage caused by the sequence of mainshock-aftershock is more serious than single earthquake.The masonry structure of villages and towns in our country is large in quantity and wide in area,and the historical record of earthquake damage is serious.The study in this paper is based on a typical masonry structure in the 2005 Jiujiang-Ruichang earthquake.On the basis of previous research,the sequence of mainshock-aftershock has been constructed according to the statistical relationship of the mainshock-aftershocks.The elastoplastic finite element analysis has been carried out to analyze the single mainshock and the mainshock-aftershock.The difference in the damage characteristics,damage dissipation energy and displacement response of the structure under the sequence of mainshock-aftershock are compared to clarify the impact of the aftershock on the seismic performance of the structure.The results show that the damage caused by aftershocks is more serious than that of the mainshock,especially intensifying the damage of the bottom floor.The damage caused by aftershock is related to the mainshock damage and aftershock strength,when the mainshock damage and aftershock strength of the structure is greater,the aftershock has a more significant impact on the structure damage.