Study on progressive collapse resistance and mechanisms of beam-column sub-assemblages

Abstract

Compressive arch action (CAA) and tensile catenary action (TCA) are the main resistance mechanisms against progressive collapse in reinforced concrete (RC) buildings. When the lateral constraints of beams are strong enough, CAA and TCA could be developed and obtain significant additional progressive collapse resistance. Lateral constraints of beams are key parameters affecting the CAA and TCA capacities. For a frame under a middle column lost scenario, the adjacent columns can carry much more loads than designed. Whether the adjacent column could provide adequate lateral constraints to beams need to be examined. Therefore, this article selected beam-column substructures as the research objects. Firstly, a new division method on resistance mechanisms was proposed considering the contributions of each action. Then a model of the beam-column substructure was established and verified with ABAQUS software. The effects of different lateral constraints and beam height on CAA and TCA capacities were investigated by changing the column dimensions and beam heights. Finally, a new theoretical model for predicting the BM capacity, CAA capacity, and TCA capacity of beam-column substructures under different lateral constraints was established. The interaction between the column and beam and the parameters of columns and beams are taken into consideration.