Experimental study on the smoke temperature distribution alongside the lining in tunnel fires

Abstract

Tunnel fire temperature is a key factor for tunnel structural safety and evacuation. This study aimed to investigate the smoke temperature distribution alongside the lining across the section and effects of pool sizes and fuels on it through a series of small-scale experiments. The results showed the heat release rates of diesel were significantly lower than gasoline's when they had the same pool size and volume. Nevertheless, the duration of diesel combustion increased obviously. As a result, the maximum smoke temperature under the ceiling for gasoline was significantly higher than diesel's. The results were subsequently adopted to compare with other test results and illustrated a similar result. The initial temperature rising rates for gasoline pool fires were shown to agree well with the standardized temperature curves, but they were significantly lower for diesel pool fires. Two exponential correlations on vertical temperature distribution were provided, respectively, for gasoline and diesel fires. These findings are expected to be useful for the design of the thermal boundary on the lining in tunnel fires.