The progressive collapse of reinforced concrete structures occurs when one or more vertical loadbearing elements are eliminated due to man-made or natural hazards. The building's weight transfers to neighboring columns in the structure, causing the failure of adjacent members and, ultimately, the failure of a portion or the entire structure. In which the collapsing system continuously searches for alternate load paths in order to survive. This study examines progressive collapse in RC structures caused by instantaneous column removal. To investigate the collapse, typical columns are removed individually and analysis and design are continued. An eight-story reinforced concrete frame structure was considered for the study. The software ETABS V20 is used to perform a linear static analysis on a model of a regular reinforced concrete (RC) frame structure. Here, three types of column removal cases are examined: corner column removal, exterior column removal, and interior column removal. Then, the calculation of Demand Capacity Ratio (DCR) for both beams and columns are considered and compared to the GSA's acceptance criteria. The obtained DCR values indicate that columns are safe and strong enough to resist progressive collapse in all cases, whereas beams for corner column removal case are not safe for progressive collapse

Progressive collapse; Iraq seismic code; DCR values; RC structure; General Services Administration (GSA)