Demonstrating adequate safety for a concrete column exposed to fire, using probabilistic methods

Demonstrating adequate safety for exceptional designs and new design applications requires an explicit evaluation of the safety level, considering the uncertainties associated with the design parameters. The recently published PD 7974-7:2019 provides five routes to demonstrate adequate safety through probabilistic methods but does not include worked examples. The case study in this paper presents three state-of-the-art approaches for demonstrating achievement of an absolute safety target (acceptance concept “AC3” in PD 7974-7:2019) for a concrete column in an office building with stringent reliability requirements, specified on the level of individual members and with respect to a standardized heating regime. The case study shows how fragility curves listed by, for example, industry organizations can support probabilistic approaches and a more comprehensive understanding of design performance.