ABSTRACT
Fire Safety in tunnels became design primary issue to define the works’ cost. Costs saving in energy, maintenance and safety management can be obtained adopting a risk-based approach. The paper presents this approach based on Fire Safety Engineering and probabilistic risk analysis. The CFD (Computational Fluid Dynamics) and egress simulations give the full integrated approach: ventilation and smoke extraction are evaluated and optimized, and egress pathways are verified by means of evacuation simulations. Risk-based design is an innovative approach of safety system dimensioning by adopting probabilistic methods to take in account different situations. The sizing of safety systems is no more based on the fire magnitude but on the global estimated risk. Alternative Risk Reduction Measures like automatic fire suppression, advanced ventilation management, traffic control measures, can be evaluated for a more effective approach. The risk-based approach can be applied dynamically, during operation, to define operational measures and maintenance priorities.
