Simplified Models of Progressive Collapse Response and Progressive Collapse-Resisting Capacity Curve of RC Beam-Column Substructures

Based on analysis of a progressive collapse mechanism, this paper presents a simplified model for static analysis of progressive collapse response of RC beam-column substructures under midspan point loading. The proposed model expresses the load-deflection response directly, and it consists of three stages-beam mechanism stage, transient stage, and catenary mechanism stage. In the model, the influence of the span, the sectional dimension, and the reinforcement of the beam on progressive collapse behavior of substructures can be taken into account. The proposed model is validated by experimental results in literature. Last, progressive collapse-resisting capacity curves of substructures are established based on the energy conservation principle, which establishes a foundation for progressive collapse assessment of RC frame structures. (C) 2014 American Society of Civil Engineers.