Resilience targets for structural fire design : an exploratory study

The adequacy of structural fire engineering designs is determined by the ALARP requirement, under the condition of design tolerabil-ity. The ALARP requirement applies both to traditional fire safety goals such as life safety, but also to questions of resilience. When confronted with uncertainty, however, an ALARP evaluation entails a detailed full probabilistic analysis, greatly increasing computational complexity. The application of a limit state approach and target safety levels as in structural engineering for normal design condi-tions would allow for a practical approximation of the ALARP as-sessment. In the presented exploratory study, the background of the target safety levels for normal design conditions are revisited, as well as their applicability for fire design. Based on these concepts, a similar approach is presented for the derivation of resilience targets (reliability indices). When the failure probabilities for the collapse and resilience (downtime) limit states are small, their target safety levels can be considered independent