Structural Robustness of Steel Structures under Exceptional Event: Column Loss Scenario

Abstract

Structural robustness ensures the safety and integrity of buildings under unforeseen events such as natural disasters or deliberate attacks. This study investigates the behavior of moment-resistant and pinned joint braced steel structures subjected to the extreme column loss scenario, aiming to identify structural requirements for robust design. The reference building in Brussels is a multi-story office building with ductile joints and restrained supports designed according to Eurocode provisions. Using geometrical and material nonlinear analysis, the behavior of the structure is examined under static loss of a column, with contributions from secondary frames and 3D effects included. The alternative load path method is employed, and analyses are conducted using CEPAO software to account for plastic hinges, second-order effects, and buckling. The findings highlight that while column location influences the structural response, the presence of moment-resistant connections, secondary beams, and catenary action significantly enhances robustness. These insights provide valuable guidance for engineers in designing more resilient steel structures against exceptional events.