Nonlinear dynamic response and progressive collapse of RC framed buildings under multiple column-loss scenarios

Progressive collapse consists in the spreading of local damage from element to element, which results in the collapse of the entire structure or a large part of it. To avoid progressive collapse, the structure should withstand events like fire, explosions, impact or the conse-quences of human error, without being damaged to an extent disproportionate to the original cause. In this study, nonlinear dynamic response of a reinforced concrete framed structure to multiple column-loss scenarios is investigated by means of fiber-based finite element capacity models and incremental-mass dynamic analysis. The influence of removal of two columns on the behavior of the structure is evaluated. The residual capacity of the structure was assessed under varying location and time of columns’ removal. Two different multiple column-loss scenarios were explored, namely simultaneous and sequential removals. Analysis results al-low the worst scenarios to be identified, as well as the sensitivity of progressive collapse re-sistance to be evaluated