Risk Analysis as Design Tool in Fire-Safety Retrofit of Two Italian Tunnels

A fire-safety retrofit was designed for two existing road tunnels in northern Italy. The design alternatives are compatible with the local geomorphology and the existing portal infrastructures. To assess the risk associated with the current condition and the design alternatives, a risk analysis procedure was implemented based on the FHWA report Prevention and Control of Highway Tunnel Fires. Because no Italian code or recommendation exists on this subject, it was necessary to tune the U.S. document to the Italian and local conditions. This risk analysis allowed both the designer and the client to assess the benefits of the design alternatives with respect to the current condition and to compare the design solutions, thus providing invaluable help in the decision-making process. The two proposed solutions increase the probability of no fatalities from zero (current state) to 64% and 68%, respectively.