A numerical study on the influence of different tunnel lining insulation materials in a road tunnel fire

Abstract

Various types of passive protection techniques have been investigated for road tunnels. A road tunnel fire is characterized by various parameters; one of the most important parameter is heat release rate (HRR). The heat release rate is considered a key parameter for design of various tunnel fire protection systems such as firefighting system, ventilation, and other passive protection systems. Many references are available from past researchers on heat release rates for different cases, where different type of vehicle/fuel was burned in a road tunnel. Later it was noticed that the heat release rate established by burning of vehicle/fuel in a tunnel gets modified by various other parameters. These parameters includes but not limited to fuel arrangements, tunnel ventilation, tunnel geometry, fixed firefighting system, fire growth rates etc. The passive fire protection systems are usually not considered as affecting heat release rates in tunnel. There is a need to better analyze this parameter in tunnel fires and to see their interaction with tunnel fire. A comparison of road tunnel with and without various passive protections under heavy good vehicle fire is studied by numerical modelling and presented under this study. This study shows tunnel protected with calcium silicate board results in higher temperature and heat fluxes compare to non-protected tunnel and tunnel protected with magnesium oxides/Cement based spray. This indicates that passive fire protection system can alter the thermal conditions inside the tunnel in case of fire.