Numerical Investigation on the Progressive Collapse Behavior of Precast Reinforced Concrete Frame Subassemblages

This paper presents a numerical investigation of the progressive collapse behavior of the precast RC frame subassemblages. An efficient numerical model for precast RC frame subassemblages under progressive collapse is developed based on an open-source finite-element software, in which the fiber beam element is used for the beams and columns and the Joint2D element is used for the beam-to-column connections. To consider the significant bond-slip effect inside the joint core of precast RC frame subassemblages, the stress-slip relationship for reinforcement bars with different embedded lengths is derived and used to generate the force-deformation relation for the springs incorporated in the Joint2D element. The numerical model is validated through comparisons with the experimental results of RC subassemblages subjected to column removal scenarios in terms of load-displacement curve, compressive arch action, catenary action capacity, and so on. Systematic parametric studies are conducted based on the validated numerical model to investigate the influence of some typical parameters of precast RC structures on the progressive collapse capacity of the subassemblages.