Estimating Limit State Capacities for OGS Building having different MF using Push over Analysis

Seismic fragility curves are one of the famous methods to address the problem of performance of building in probabilistic approaches. It considers the uncertainties in load and demand; it gives reliable results to take decisions. In seismic fragility analysis, curves for different structural performance levels are plotted against the structural demand. The structural capacities or structural limit state (LS) capacities is of crucial importance. LS capacities are elaborated in design codes and several research has done to estimate the LS capacities using Push over analysis. However, there is an uncertainty in the building due to the presence of infill walls as well; infill walls add additional stiffness against lateral loads. And in the case of Open Ground Storey (OGS), the complexity is added to one more level due to the absence of infill walls in ground storey. International codebooks suggest to use magnification factor (MF) in ground storey to have good performance under lateral loads for OGS building. The present study focuses on evaluating the LS capacities for buildings from two storey to eight storey buildings with different scheme of MF. The results shows that there is a wide disparity in storey wise LS capacities.