Increasing robustness of reinforced concrete structures under column loss scenario

This paper presents a simple technique to enhance robustness of reinforced concrete (RC) plane frames to progressive collapse under column loss scenario. The response of the enhanced/mitigated RC frames is analyzed using fiber force-based finite element analysis and applying displacement-controlled nonlinear static pushdown at the location of failed column. The technique involves addition of external unbounded steel cables to the continuous beam in each floor at anchorage and deviator locations. The cables transfer the loads above the failed column to the anchorages and deviators that are assumed to perform as rigid arms, which in turn redistribute the loads to adjacent columns. The numerical model computes the frame progressive collapse robustness using push-down analysis to simulate a column elimination and estimate the effects of cable catenary action on the frame. Two-dimensional RC frame of six stories and four bays was adopted in the study. The numerical results demonstrate the prospect of increasing robustness of RC frames to progressive collapse using presented technique.