The assessment of the seismic performance of the RC buildings having one or two soft-stories retrofitted with gapped inclined bracing

Amir Abbas Shahsahebi | Zakariya Waezi

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=116786
Date :  2019/11/11
Publish in :    هشتمين کنفرانس بين‌المللي زلزله‌شناسي و مهندسي زلزله


Keywords :طبقه نرم، عملکرد لرزه‌اي، مقاوم‌سازي لرزه‌اي، مهاربند اريب شکافدار GIB، خسارت لرزه‌اي

Abstract :

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One of the methods of retrofitting the structures having soft-stories is taking advantage of their longer periods via gapped inclined bracing(GIB). The basis of this method lies on the concentration of the maximum drifts within the first story which plays the role of an isolator and protects other stories from seismic hazards. The main purpose of this study is to investigate the efficiency of the using GIB at the soft stories of the structures satisfying the ductility consideration of the modern codes. In order to assess the performance of the proposed method of retrofitting, RC moment-resisting frame structures with 4 and 8 stories designed according to the Iranian seismic codes are adopted. The 4 and 8-story structures are modelled as 8 and 12 2-D frames variants using lumped plasticity models in Opensees software, respectively. The optimized GIB parameters are determined according to a nonlinear static analysis and incremental dynamic analyses are performed to prove their effectiveness. The results of the nonlinear dynamic analyses are applied to compare the seismic behavior and the failure mechanisms of different variants. In order to estimate the economic advantages of the proposed retrofitting methods, the PEER loss estimation method has been implemented to calculate the structural and non-structural losses. The loss results indicate that as opposed to high-rise buildings, using this method is very beneficial for low-rise ones from economical and performance points of view.