ABSTRACT
Currently, progressive collapse of structures is a big concern of government agencies (GSA, 2003, DoD, 2010). The experimental research on Reinforced Concrete (RC) frames subjected to Middle Column Removal Scenarios (MCRS) shows that the eventual structural failures were typically controlled by bar fracture at or near joint interfaces (Sasani and Kropelnicki, 2008, Yi, et al., 2008, FarhangVesali, et al., 2013, Yu and Tan, 2013). With adequate lateral restraints in the aforementioned tests, structural mechanisms of compressive arch action and catenary action are mobilized. At section levels, beam sections are subjected to combined action of bending moment and axial force. Cracks are easily concentrated at joint interfaces, in particular for the joint just above a removed column.
