ABSTRACT
The extension of Line 1 of Naples from Centro Direzionale station to Capodichino is one of the most complex underground project ongoing in Italy. Provided that main point of complexity is surely the structural and architectural design, this kind of challenging project cannot avoid safety studies. One of the most significant and crucial aspects concerning this matter is fire scenarios handling. Ventilation is one of the major measures at tunnel designer disposal to mitigate the effect of fire and smoke, to aid evacuation, rescue services, and firefighting in a tunnel fire. In case of a tunnel fire, fire ventilation systems are required to control smoke flows and create paths for evacuation and firefighting. Nowadays the most used emergency ventilation system is the longitudinal one. The most recent design standard includes the application of Fire Safety Engineering. This innovative approach is nowadays also foreseen in Italian specific law for subway construction. Two key parameters for tunnels with longitudinal ventilation, that is, critical velocity and backlayering length are presented. For smoke extraction systems, sufficient air flows are required to be supplied to prevent smoke spread. Will be shown how this concept is also applicable in case of fire train in stations. Regarding Naples Line 1 project, firstly one-dimensional fluid dynamic simulations will be presented, then 3D simulations will be showed to give an example of how these tools can help us in the design phase.
