Seismic performance assessment of self-centering dual systems with different configurations

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• 作者：Mehdei Kafaeikivi^a ; David A. Roke^b ; ^{roke@uakron.edu" class="auth_mail" title="E-mail the corresponding author} ; Qindan Huang^b
• 关键词：Lateral resisting systems ; Self-centering systems ; Performance assessment ; Seismic fragility ; Interstory drift prediction
• 刊名：Structures
• 出版年：2016
• 出版时间：February 2016
• 年：2016
• 卷：5
• 期：Complete
• 页码：88-100
• 全文大小：1579 K

文摘

Concentrically braced frame (CBF) systems have limited capacity for lateral displacement, causing structural damage that leads to high post-earthquake costs under moderate earthquakes. Self-centering concentrically braced frame (SC-CBF) systems have been developed to soften the lateral force–lateral drift response of the system without causing structural damage; however, the construction cost of SC-CBF systems is expected to be high due to the precision required in fabrication and erection. To take advantage of the ductility of SC-CBFs and the economy of conventional CBFs, a novel dual system has been proposed in which the lower stories of the lateral force resisting system are SC-CBFs and the upper stories are conventional CBFs. The SC-CBF system in the lower part of the dual system is intended to soften the CBF system's behavior and act as a ductile substructure for the CBF, reducing the post-earthquake costs (with respect to a full conventional CBF system) and the construction costs (with respect to a full SC-CBF system) in the dual system.

Several combinations of SC-CBF and CBF stories can comprise the proposed dual system; more SC-CBF stories would be desirable to reduce damage during seismic response, but leads to more construction cost. To compare the different dual system configurations, seismic fragility curves are used to quantify the structural performance. In this study, probabilistic demand models for the selected engineering demand parameter are developed for assessing fragilities considering three performance levels. The demand model parameters are assessed based on nonlinear time history analysis of finite element models subjected to a suite of seismic ground motions. The results of this study show that the dual system has a better seismic performance for given seismic intensity than the CBF system.