Vulnerability assessment of residential steel building considering soil structure interaction

Special moment resisting steel frame structures are now being used commonly in highly seismic regions as seismically reliable structures. However, a very important parameter describing the dynamics of steel structures during earthquake loading, Soil Structure Interaction (SSI), is generally neglected. In this study, the significance of consideration of flexibility of soil in being able to obtain a result closer to reality is asserted. The current paper focuses on calculation of seismic fragility curves special moment resisting steel frame structures under different earthquake loadings for fixed-base and SSI models. The observation of obtained fragility curves lead to the conclusion that the SSI has a considerable effect on component fragility for the steel structures, with its effects decreasing for higher peak ground acceleration. The results show that the structures when considered SSI have a higher probability of exceeding a damage limit state. This observation attests the role of SSI in the accurate study of structural performance.