Influence of Multicolumn Removal on the Behavior of RC Floors

Abstract

With the numerous catastrophic incidences of progressive collapse in the past, there has been increasing interest from both engineering and academic communities toward evaluating the ability of reinforced concrete (RC) structures to resist progressive collapse. Of the numerous studies conducted in the past decade, the majority has focused on scenarios in which a single vertical loading bearing member, such as a column, is removed. However, accidental events (such as terrorist attacks or vehicular impact) often cause severe initial damage with multicolumn removal. Recognizing this fact, this study aims to assess the effects of multicolumn removal on the overall performance and load resisting mechanisms of RC structures. Two multipanel beam-column-slab substructures were tested, differing only in the number of columns to be removed. The test results collected included failure modes, load resisting capacities, deformation capacities, strain gauge results, horizontal movement of supports, and torsional rotations of edge beams. Based on test observations, a simple approach is given to evaluate progressive collapse vulnerability of RC buildings under single or multiple column removal scenarios.