Katie McQuade-Jones – WSP USA
For a road tunnel with a length around 305 m long or shorter, there is a question as to whether mechanical ventilation is necessary. To use natural ventilation, an engineering analysis must be conducted that demonstrates equivalency of life safety outcomes with mechanical ventilation. FDS+EVAC is used to quantify this equivalency of life safety outcomes for a short tunnel. The analysis accounts for toxic and irritant gas species impacts on evacuating occupants, as well as thermal impacts. The outcome is an FDS+EVAC analysis using FED and FIC, which provides a quantitative basis for the eventual code compliant (NFPA 502) solution.