Numerical evaluation of the reliability of using single-story substructures to study progressive collapse behaviour of multi-story RC frames

Progressive collapse is a global failure for a multi-story building. All stories above the removed column will consequently deform and help redistribute the loads initially withstood by the removed column. However, due to cost and excessive time to be involved, the majority of existing experimental researches regarding progressive collapse rely on single-story beam-column substructures or sub-assemblages. To date, how to use the results from single-story substructures or sub-assemblages to fully or confidently study the behavior of multi-story building is still unclear. Thus, it is imperative to investigate the relationship between the results of single-story substructures and the real behavior of multi-story buildings. Thus, for this purpose, in the present study, a series of planar multi-story reinforced concrete (RC) beam-column substructures were modeled using high-fidelity finite element software LS-DYNA. Firstly, the numerical models were validated by the test results of two three-story planar substructures with different design spans. Secondly, the validated models were explored on various load resistance of each story in the investigated multi-story frame. In addition, the effects of boundary conditions, missing column locations, story numbers on the variation of load resistance were studied in detail using the models.