Improved progressive collapse resistance of irregular reinforced concrete flat slab buildings under different corner column failures

Abstract

As the flat slab building with irregular geometric configurations is commonly designed to advance urban development and for architectural demands, its behaviour to resist progressive collapse must be examined. The building's progressive collapse occurs when one or more vertical structural load-bearing elements such as columns are removed due to an extreme load caused either by natural or manmade hazards. The present analytical research examines the failure criteria and improvement in the progressive collapse resistance of five and ten-storey irregular R.C flat slab building by incorporating perimeter beams along with strengthened perimeter columns in the building. The progressive collapse study is conducted by removing different corner columns on the ground floor as per the GSA guidelines (2003) and assessing the spread of damage. Static analysis is performed using the structural analysis program ETABS 2016. For each case, the results have been taken in terms of demand capacity ratio (DCR) at critical sections and, chord rotation and joint displacement at locations of removal of columns. The results showed that the presence of strengthened columns provides sufficient stiffness and the perimeter beam provides load paths for the building's gravity loads, thus making it resistive to progressive collapse under column failure.