Self-centering seismic retrofit scheme for reinforced concrete frame structures:SDOF system study

作     者：Yunfeng Zhang and Xiaobin Hu Department of Civil and Environmental Engineering,University of Maryland,College Park,MD 20742,USA 

作者机构：Department of Civil and Environmental Engineering University of Maryland College Park 20742 USA 

出 版 物：《Earthquake Engineering and Engineering Vibration》 (地震工程与工程振动（英文刊）)

年 卷 期：2010年第9卷第2期

页      面：271-283页

核心收录：

学科分类：081405[工学-防灾减灾工程及防护工程] 08[工学] 0814[工学-土木工程] 

基　　金：Univeristy of Maryland Start-up Grant to the First Author 

主　　题：earthquake reinforced concrete frame structure nonlinear analysis SDOF system seismic retrofit self-centering 

摘      要：This paper presents the results of a parametric study of self-centering seismic retrofit schemes for reinforced concrete (RC) frame buildings. The self-centering retrofit system features flag-shaped hysteresis and minimal residual deformation. For comparison purpose,an alternate seismic retrofit scheme that uses a bilinear-hysteresis retrofit system such as buckling-restrained braces (BRB) is also considered in this paper. The parametric study was carried out in a single-degree-of-freedom (SDOF) system framework since a multi-story building structure may be idealized as an equivalent SDOF system and investigation of the performance of this equivalent SDOF system can provide insight into the seismic response of the multi-story building. A peak-oriented hysteresis model which can consider the strength and stiffness degradation is used to describe the hysteretic behavior of RC structures. The parametric study involves two key parameters -the strength ratio and elastic stiffness ratio between the seismic retrofit system and the original RC frame. An ensemble of 172 earthquake ground motion records scaled to the design basis earthquake in California with a probability of exceedance of 10% in 50 years was constructed for the simulation-based parametric study. The effectiveness of the two seismic retrofit schemes considered in this study is evaluated in terms of peak displacement ratio,peak acceleration ratio,energy dissipation demand ratio and residual displacement ratio between the SDOF systems with and without retrofit. It is found from this parametric study that RC structures retrofitted with the self-centering retrofit scheme (SCRS) can achieve a seismic performance level comparable to the bilinear-hysteresis retrofit scheme (BHRS) in terms of peak displacement and energy dissipation demand ratio while having negligible residual displacement after earthquake.