Robustness of RC buildings to progressive collapse: Influence of building height

The influence of building height on the robustness of reinforced concrete (RC) frame buildings to resist progressive collapse is investigated. Beginning with the initial removal of a corner column at the ground level, the study attempts to identify the main global resisting mechanisms that develop in the structure after successive column removals and provides an assessment of the building robustness with varying height. Nonlinear simulation models of three, six and ten-story RC frame buildings using reduced-order modeling scheme were developed in LS-DYNA and the results were analyzed to gain insight into the factors that influence the ability of the structure to accommodate vertical load redistribution, develop arch and catenary action, and trigger Vierendeel effects. It is observed that taller buildings possess greater resilience to progressive collapse than buildings with fewer stories for the same arrangement of vertical elements in the building plan, although a comprehensive analysis of the failure modes also indicates that this finding cannot be extrapolated to conclude that collapse resistance will continue to increase with increasing buildings height. The research provides a basis for comparing the relative robustness of buildings subjected to column losses on the lowest floor and, consequently, findings from the study provide engineers with an insight into measures to improve the robustness of a building to resist progressive collapse.