Dynamic behavior of RC frames against progressive collapse subjected to loss of a corner column scenario

Abstract

In light of increasing concern about the progressive collapse of reinforced concrete (RC) structures, this study investigates the dynamic performance of RC frames against progressive collapse triggered by corner column removal as the dynamic response under such a scenario is still not fully understood. High-fidelity numerical models were built using software LS-DYNA. The model was validated through a comparison between numerical and experimental results. After this validation, a parametric analysis was conducted to explore the dynamic performance of structures following sudden corner column removal. A comparison was made between the load resistance and load transfer mechanisms of the RC frames under quasi-static and dynamic regimes. The effects of critical factors, such as strain rate and damping ratio, were discussed. Additionally, influences of slab thickness and the constraints from upper stories of the frame were also quantified. It was found that the energy-based method could effectively evaluate the dynamic resistance without inclusion of the effects of strain rate and damping ratio. It found that the effects of strain rate are negligible, while the damping ratio is crucial, as it reduces vibrations, peak displacement, and amplitude. The dynamic responses are greatly affected by the slab thickness. Meanwhile, the constraints from the upper floor of the frame can significantly mitigate the dynamic responses.