Theoretical evaluation method for the progressive collapse resistance of steel frame buildings

Abstract

Steel-concrete composite slabs are widely adopted in steel frame buildings as the gravity load resisting system. So far, the progressive collapse resistance of this type of structure is mainly evaluated by the experimental or numerical methods, which is complicated, time-consuming and expensive. Hence, in this study, an easy-to-use theoretical method for giving a quick evaluation of the progressive collapse resistance at the design stage is proposed for this type of structure. When the floor system is horizontally constrained at the parallel boundaries, the theoretical model is composed of three stages, i.e., elastic stage, plastic stage, and catenary stage. At the elastic stage and plastic stage, the load is carried by the flexural resistance of the floor system. At the catenary stage, the load is resisted by the catenary action and the tensile membrane action. When the floor system is not constrained at the parallel horizontal boundaries, the theoretical model is only composed of elastic stage and plastic stage. Then, this theoretical model is validated with different experimental and numerical simulation results. Finally, for the multi-story and high-rise buildings, considering the potential instability of columns under the excessively redistributed gravity load, the potentially maximum tributary area of each column under the progressive collapse scenario is presented.