Stability Assessment of Steel Moment Frames against Progressive Collapse

Analyzing progressive collapse plays a pivotal role in diagnosing structure stability caused by earthquake, explosion, car crashes, and fire and so on. In the current research, condition of progressive collapse has been analyzed in structures which have been designed based on current codes in Iran. For this purpose, a couple of steel buildings with steel moment frame systems that have many stories and various bay, have been evaluated. With sudden removal of each column, the possibility of bridging over other elements has been studied; besides, alternative path method introduced by the UFC 4-023-03 code has been applied in the assessment process. Results indicate that the beams located on the highest floor do not have a suitable performance and in case of sudden removal of each of the columns, it will be impossible to bridge over other elements and it will face collapse and progressive collapse in spite of the fact that other members are resistant against the collapse.