The Challenges of Effective Risk Assessment and Safety Management of Fire and Explosion Hazards

The methodology of risk assessment is commonly implemented in many engineering projects for safety management of fire and explosion hazards from the project initial design to the decommissioning. Hazard identification and quantitative analysis of the consequences are crucial stages for an effective risk assessment. The decisions on the risk ranking and the priority for safety measures rely on the outcomes of the quantitative risk assessment (QRA) which often involve costs and benefits assessment. Those process require historical data and numerical models for consequence analysis. Lack of the historical data and the knowledge gaps in the consequence models is one of the main sources of uncertainties in risk assessment. This paper presents a case study of the role of historical data and bridging the knowledge gaps with commissioned research projects in the tunnel fire safety to overcome the uncertainties in risk assessment and improve the safety of the road tunnels. The fire disasters in the Mont Blanc tunnel, the Tauern tunnel, the St. Gotthard tunnel, and the Channel Tunnel were analysed. The strategies of the restoration of those tunnels showed that the results from the experimental programs of the full scale and the reduced scale tunnel fires reduced uncertainties in some of tunnel safety design parameters such as the critical velocity for the ventilation. Safety measures to deal with high consequence tunnel fires such as HGV fires are discussed.