Performance of Three-Dimensional Reinforced Concrete Beam-Column Substructures under Loss of a Corner Column Scenario

Abstract

The vulnerability of conventional reinforced concrete (RC) structures to structural failure due to the loss of corner columns has been emphasized over the past years. However, the lack of experimental tests has led to a gap in the knowledge for the design of RC building structures to mitigate the likelihood of progressive collapse caused by losing a ground corner column. Seven one-third scale RC beam-column substructures were tested to investigate their performance. The variables selected for the test specimens included: beam transverse reinforcement ratios, type of design detailing (non-seismic or seismic) and beam span aspect ratios. Shear failure was observed to have occurred in the corner joint and a plastic hinge was formed at the beam end near to the fixed support in the non-seismic detailed specimens. However, plastic hinges were also formed in the beam end near to the corner joint for the seismically detailed specimen.Vierendeel action was identified as the major load redistribution mechanism before severe failure occurred in the corner joint but a cantilever beam redistribution mechanism dominated after corner joint suffered severe damage. The test results were compared with the DoD design guidelines to highlight the deficiencies of the recently updated guidelines.

Enhanced external progressive collapse mitigation scheme for RC structures

“…For the simulated column removal scenarios corresponding to the least vertical deformations, the resistance of the progressive collapse was primarily provided by Vierendeel frame action, floor system in-plane action, and axial compressive force-moment interaction of beams. Several research studies were performed by Qian and Li (2013a, 2013b, 2012a, 2012b to predict beam-slab behaviour to mitigate progressive collapse as a result of corner column removal. Qian and Li (2013a) performed push-down tests on seven one-third scale RC beam-column connections to investigate their behaviour.…”

“…Several research studies were performed by Qian and Li (2013a, 2013b, 2012a, 2012b to predict beam-slab behaviour to mitigate progressive collapse as a result of corner column removal. Qian and Li (2013a) performed push-down tests on seven one-third scale RC beam-column connections to investigate their behaviour. Parameters considered in their tests included transverse steel reinforcement ratios, beam detailing, and beam shear span ratios.…”

“…Performance results showed that columns with drop panels increase the strength by 124.7% and; therefore, substantially reduce progressive collapse. Qian and Li (2012a) carried out a number of dynamic tests on six one-third scale RC beam-column specimens to simulate progressive collapse behaviour in the event of a corner column failure. Each specimen had different length, design detailing, and shear span ratio and was designed for testing to investigate the dynamic load redistribution performance following a sudden removal of a corner support.…”

Analysis on Dynamic Response of Reinforced Concrete Frame for Resisting Progressive Collapse

“…The experimental results showed that the frame with middle column failed would go through three phases including elastic, plastic and catenary phases. Qian and Li [10] conducted seven one-third scale RC beam-column substructures to investigate the behavior under the scenario of being subjected to the loss of one ground corner column. It was proposed that increasing the flexural capacity of the beam section and upgrading the shear strength of the corner joint could improve the performance of frames against progressive collapse.…”

Monotonic Loading Tests of RC Beam-Column Subassemblage Strengthened to Prevent Progressive Collapse

“…Four first-story columns were physically removed from the building to understand the subsequent load redistribution within the building. In Qian and Li (2013) experimental study of seven one-third scale RC beam-column substructures were tested to investigate the effect of beam transverse reinforcement ratios, type of design detailing, and beam span aspect ratios. Recently Qian et al (2015) tested 6 one-quarter scaled specimens to investigate the progressive collapse resisting capacity of RC frames including secondary mechanisms such as membrane actions developed in slabs.…”