Comparative Study of Progressive Collapse Potential of Steel Moment Resisting Frame and Braced Frame

Progressive collapse is a situation where local failure of a primary structural component leads to the failure of adjoining members, which in turn leads to spread of failure resulting in the collapse of an entire structure or disproportionately large part of it. In this paper, the effectiveness of inverted V type bracings on progressive collapse resistance of steel building is presented. 4-storey moment resisting steel frame building is considered for the study. Progressive collapse analysis is carried out under ten different column and/or bracing removal scenario from the ground floor level by following the U. S. General Services Administration (GSA) guidelines. Linear Static and Linear Dynamic analysis is performed to evaluate progressive collapse potential of 4-storey steel building considered for the study using SAP2000 software. Alternate Path Method (APM) is used to determine the Demand Capacity Ratio (DCR) of selected beam, column and bracing members located in surrounding of removed column. From the analysis results in terms of DCR of beams and columns, it is observed that the addition of bracing members, reduces the risk of progressive collapse.