ABSTRACT
Recent incidents however have drawn widespread attention to the risks of fires in road, rail and masstransit tunnels (e.g. King’s Cross, Channel Tunnel, Mont Blanc, Tauern, Gotthard). The incidents have resulted in casualties as well as large direct and indirect economic damage. The control of smoke flow during a road tunnel fire is often an important part of fire safety measure. On the other hand, CFD (Computational Fluid Dynamics) simulations are increasingly used to estimate the effects of fires in road tunnels. However, little work has been done to analyze comprehensive fire characteristics of the large cross-section road tunnel. On the basis of CFD method and with the help of FDS simulation software, this paper conducted simulation analysis of lorry and car fires for large cross-section road tunnel. Two fire scenarios were constructed and five different kinds of longitudinal ventilation conditions were considered. The smoke distribution feature was discussed and the corresponding results of critical ventilation velocity were also compared with the values calculated by related empirical formula. It would be helpful to work out a ventilation system strategy for the road tunnel.
