Analysis on Compressive Membrane Mechanism Based Progressive Collapse Bearing Capacity of RC Frame Considering Floor Slab Action

To study the progressive collapse resistance of reinforced concrete frame structures considering floor slab action, a finite element model for progressive collapse analysis of beam-slab structures was established using SAP2000. The accuracy and rationality of the analysis model were verified by 12 specimens from the existing progressive collapse tests. Then, we defined an increasing factor for assessing the compressive membrane mechanism based progressive collapse bearing capacity considering the action of the floor slab. The influence of parameters, such as concrete strength, slab thickness, and reinforcement ratio, on the increasing factor was studied. The results show that, after considering the action of the slab, the collapse resistance of the structure increases significantly, the compression arch effect of the beam near the side column beam also increases, and the displacement reduces when the bearing capacity rises again. The increasing factor of bearing capacity increases significantly with the increase of the concrete strength grade, the aspect ratio of the slab, the reinforcement ratio at the bottom of the beam, and the beam height. However, the increase factor of the bearing capacity decreases with the increase of the thickness of the slab, the reinforcement ratio at the top and bottom of the slab, and the reinforcement ratio at the top of the beam. © 2021, Editorial Department of Journal of Hunan University. All right reserved.