Studies on secondary progressive collapse‐resistance mechanisms of reinforced concrete subassemblages
Min Huang, Hua Huang, Runqi Hao, Zhen Chen, Ming Li, Wanchao Deng
Abstract
Abstract The developments of compressive arch action (CAA) and tensile catenary action (TCA) in beams can provide secondary loads for resisting progressive collapse. However, to date, the contributions of CAA and TCA in regards to progressive collapse have not been considered in design codes, owing to inadequate studies. In this study, a division of resistant mechanisms was initially proposed. Then, based on an experimental model of beam‐column subassemblages, a finite‐element model was established using ABAQUS software, and was validated against experimental results. Subsequently, the calibrated finite element model was employed to study the effects of different constraints (such as ideal fixed constraints, sliding constraints, the beam‐column stiffness ratio, and axial compression ratio) on the secondary progressive collapse‐resistance mechanisms of reinforced concrete (RC) subassemblages. The results show that when the constraints are weaker than the fixed supports, the CAA capacity is larger than that of the TCA. The axial compression ratio in the column slightly increases the first peak load, but the beam‐column subassemblages fail earlier, owing to the large eccentric bending moment. The CAA capacity and TCA capacity increase with a decreasing beam‐stiffness ratio, and the CAA capacity increases faster than the TCA capacity. In addition, a theoretical model is proposed for assessing the resistance provided by a CAA.