Citation

Hua N, Tessari A, Elhami-Khorasani N. Fire Technol. 2021; 57(1): 361-392.

Copyright

(Copyright © 2021, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1007/s10694-020-01007-8

PMID

unavailable

Abstract

Extreme fire events in tunnels can have catastrophic consequences, including loss of lives, structural damage, and major socioeconomic impacts. The fire scenario itself is one of the primary parameters that would influence the level of damage in a tunnel. Standard hydrocarbon fire temperature-time curves exist but they are idealized and do not consider the actual fire duration and potential for fire spread within the tunnel. Furthermore, risk-based decision-making frameworks and performance-based design of tunnel linings require realistic sets of fire scenarios to quantify damage. This paper focuses on quantifying uncertainties in the temperature-time evolution of railway tunnel fires considering fire spread between train cars. In this study, 540 numerical simulations are conducted in fire dynamics simulator by varying ventilation velocity, amount of fuel, tunnel slope, ignition point, and criteria for fire spread between railcars. Temporal and spatial distribution of fire temperature in the tunnel is studied. The resulting 540 temperature-time curves at sections with the highest temperature are analyzed and statistics of the maximum fire temperature and duration, heating rate, and decay rate are provided. Fires with heat release rates larger than 40 MW are categorized as high-intensity with mean maximum temperature of 1007°C. Fires with heat release rates smaller than 30 MW are categorized as low-intensity with a mean maximum temperature of 245°C. The proposed framework can be expanded in future to establish guidelines for temperature demands in the design of concrete tunnel linings within risk-based frameworks to achieve required performance levels in railway tunnel fire events.

Language: en