Probabilistic Seismic Assessment of Linked-Column Frame under Consecutive Earthquakes

Recent studies show that aftershocks can intensify structural damage and even lead to collapse of the structures. Among the structural systems, moment frames show desirable ductility, but in such systems damage spreads in many structural elements. Accordingly, it is possible for these systems to experience more severe damage during an earthquake. Recently, Linked-Column Frame (LCF) is introduced to limit structural damage in moment frames which can prevent formation of plastic hinges in major structural members. However, only a limited number of investigations are carried out on this systems and there is a lack of study that investigates post-mainshock performance of this system. The aim of this study is to investigate the influence of mainshock-afteshshock (MS-AS) sequence on LCF system and compare the results with conventional moment frames. For this reason, SAC 3-story building, which is designed according to UBC-94, is modeled and analyzed in OpenSEES software package. In the first step, behavior of these structures is investigated using nonlinear dynamic analysis. In the next step, incremental dynamic analysis is employed for different performance levels including IO, LS, and CP states to gain a better insight about the behavior of these structure in MS-AS sequences. Results show that MS-AS sequences can lead to increase in drift response of the frames with both systems. However, LCF shows a superior performance during seismic sequences.