Seismic Fragility Analysis of Vertically Irregular Steel Framed Buildings

Abstract

Disaster mitigation of the country requires the data of fragility curves for various typical buildings. As the number of steel buildings in the cities is increasing, development of seismic fragility curves of steel buildings are also the need of the hour. This study discusses the fragility curves and damage index functions of a 7-storey regular and irregular steel-framed buildings subjected to different earthquake ground motions. Each building was designed based on the codes, IS 800 (2007) and IS 1893 part 1 (2016). Time History Analysis of various vertically irregular framed buildings was performed and displacements of each floor were obtained. Inter-storey drift ratio and spectral acceleration at fundamental period are taken as damage parameter and intensity measure for deriving the fragility curves. The probabilistic seismic demand models for typical stiffness and mass vertical irregular buildings were developed. Steel framed buildings with ground storey open were found to be the vertically irregular building which is the most vulnerable out of all the selected vertical buildings.