Abstract
The progressive collapse of structures, and reinforced concrete (RC) in particular, has recently been the focus of practicing structural engineers. This paper aims to study numerically the limitations for the development of compressive arch and catenary actions in RC special moment resisting frames (SMRFs) when exposed to abrupt column-loss scenarios due to the risk of accidental events such as blast attacks. A finite element (FE) model that incorporates nonlinear materials behavior, bond-slip behavior at the concrete-to-steel rebar interface, and strain rate effect was prepared to study the behavior of RC frame assemblies under column-removal scenarios. The FE model was calibrated against a model-scale RC SMRF specimen tested for a column-removal scenario. The calibrated model was employed for studying the effect of various assembly types, viz. 3D assembly with slabs, 3D assembly without slabs, and 2D assembly on the behavior of RC SMRFs under a column-removal scenario. For the 2D assembly, different parameters were varied for numerical study. A new relative stiffness parameter was first introduced in this study to evaluate the potential for the development of catenary and compressive arch actions in RC SMRFs under abrupt column-removal scenarios.