Fire safety assessment of tunnel structures

Tunnels and underground structures are becoming more and more essential these days, when installing new transportation infrastructures in congested areas as well as when raising the qualities within the existing urbanizations. The realization of such structures calls for specific measures regarding durability provisions, commitment to environmental aspects, issues of sustainability and safety assurance, for their whole lifecycle.

The design for safety of tunnel infrastructures is a multifaceted process, since there are many aspects that need to be accounted for, regarding different aspects (e.g. structural and non structural, organizational, human behavior). This is even more truth for the fire safety design of such structures.

Fire safety in tunnels is challenging because of the particular environment, bearing in mind also that a fire can occur in different phases of the tunnel’s lifecycle. Plans for upgrading fire safety provisions and tunnel management are also important for existing tunnels. In this study, following a brief introduction of issues regarding the above mentioned aspects, the structural performance of a steel rib for a tunnel infrastructure subject to fire is assessed by means of nonlinear analyses for different fire exposures.