Abstract: Progressive collapse of a structure happens when one or more primary members are suddenly lost due to an unfortunate accident such as a gas explosion, bomb attack, fire, or overloaded. Building irregularity is one aspect that might aggravate the damage caused by gradual failure. The progressive failure of high rise stepped frames was investigated using 3-dimensional modelling and the finite element approach in this paper. The steel structure has 30 stories and rigid moment-resisting steel frames. Abaqus software is used to perform nonlinear dynamic analysis in accordance with GSA criteria. The results of Abaqus model are verified with an experimental data and good agreement is achieved. The structural behaviour of the building und...