Design Criteria of Electrical Systems for Roadway Tunnels Tested by Fire Simulations

This paper analyzes improvement criteria for the service continuity, the design, construction and verification of electrical systems in road tunnels. Fire prevention in road tunnels must satisfy the primary safety objectives relating to the people safeguarding and the assets protection against fire risks, complying with the sustainability criterion. At this aim, design parameters are identified as the temperature exposure levels (TEL) and the necessary equipment qualification categories (EQC) that characterize their thermal resilience and adequacy to severe environments. Primary objective is to guarantee the service continuity of electrical systems in ordinary operation and in emergency during and after a fire. Effective measures are to apply the zoning and layering criteria of roadway tunnels that suggest specific system topologies as the special 'brush' distribution as confirmed by tests of fire simulations. The knowledge of these results help to limit the feeling of uncontrolled panic in people who are in the tunnel during a fire event. A detailed analysis of the results can assist the operators of the intervention services in the decision making of rescue and extinguishing operations.