Fire safety assessment and optimal design of passive fire protection for offshore structures

The article presents a unified probabilistic approach to fire safety assessment and optimal design of passive fire protection on offshore topside structures. The methodology was developed by integrating quantitative risk analysis (QRA) techniques with the modem methods of structural system reliability analysis (SRA) and reliability based design optimisation (RBDO). Reliability analysis methodologies are presented for both plated (e.g. fire and blast walls) and skeletal structures (deck framing), which take into account uncertainties in fire and blast loading, thermal and mechanical properties of the steel and insulation. Probability of component and system failure are evaluated using first- and second-order reliability methods (FORM/SORM). The optimisation of passive fire protection is performed such that the total expected cost of the protection system is minimised while satisfying reliability constraints.