Progressive Collapse Induced by Column Removal in Reinforced Concrete Frames

Progressive collapse occurs when a sudden event such as a blast or an impact load influences a structure. Wherein, loss of continuity and low ductility of the remaining structural members result in total collapse of it. Alternate Path Method (APM) is an efficient method to study progressive collapse that is recommended in common guidelines such as GSA and UFC. APM check outs alternate paths in remained structure to resist progressive collapse due to key elements loss. This research surveys different scenarios of column elimination in planar regular and irregular frames by conducting non-linear dynamic analysis. Verification of the selected methods is conducted via analyzing an experimental model. Generally removal of corner column leads to significant responses compared with other scenarios. Moreover, eliminating a column in irregular frame causes large displacements and beam rotations which could be attributed to uneven distribution of forces in structural members; so regularity is an important factor to resist collapse.