Assessing the Effectiveness of Roof‐Level Retrofitting Beams in Enhancing the Robustness of Steel Building Structures

Abstract Improving the robustness of existing buildings is essential to ensure their ability to withstand extreme events, significantly reducing the risk of progressive collapse and its consequences in terms of deaths, injuries and economic costs. Although there are multiple solutions to improve the robustness of existing buildings, most of them are very intrusive, making their adoption costly and limited. A promising alternative is using retrofitting beams at the roof level. Such an alternative is a less intrusive and more economical solution. This study presents a methodology based on optimised computational modelling to evaluate the feasibility and effectiveness of roof‐level retrofitting beams in steel buildings. The developed framework enables the exploration of different retrofitting beam configurations in a set of representative buildings. The results demonstrate that retrofitting beams at the top floor of buildings can significantly enhance structural robustness while minimizing alterations and interventions in the existing structure. The developed methodology facilitates the broader application of this retrofitting technique, promoting its adoption and contributing to the protection of existing buildings against extreme events.