A Comparative Study of Seismic Performance of Steel Framed Buildings with Varied Plan-Asymmetric Properties

This study looks at the influence of plan-asymmetric properties on seismic performance of steel framed buildings by means of a comparative study. The seismic fragility curves of a symmetrical nine-story steel framed building and three asymmetric-plan buildings, which are the variations of the mentioned symmetrical building, are constructed through incremental dynamic analysis (IDA). The three asymmetric-plan buildings are torsionally stiff (TS), torsionally similarly stiff (TSS), and torsionally flexible (TF) buildings, respectively. The considered plan-asymmetric properties are eccentricity ratio and uncoupled frequency ratio. A comparative study of three damage states (DS) including immediate occupancy (IO), collapse prevention (CP), and global instability (GI) of the four buildings is conducted. The results show that in terms of slight damage, both the symmetrical building and the TSS building perform better. In terms of severe damage and collapse, the symmetrical building obviously outperforms the other three asymmetric-plan buildings. In addition, the TF building always performs the worst regardless of the DSs.