Abstract A series of scaled fire tests were conducted in a model bifurcated tunnel to investigate the influence of ramp slope on fire behaviors of ethanol pool fire under natural ventilation. Four ramp slopes of 0%, 3%, 6% and 9% with three fuel areas were varied. The maximum ceiling temperature in main tunnel and longitudinal temperature decay along the ceilings of horizontal main tunnel and ramp were measured and analyzed. Results show that the maximum ceiling temperature in the main tunnel increases as ramp slope increases, which is mainly due to the comprehensive effect of more ceiling flame caused by more air inflow, the increase of burning rate and the enhancement of heat accumulation. Furthermore, two modified models taking the influence of ramp slope into account are proposed based on current experimental results. The longitudinal temperature decay along ramp ceiling is influenced by slope, while the influence of ramp slope on the longitudinal temperature decay in main tunnel is relatively weak. In addition, empirical correlations are then proposed in accordance with an exponential function to include ramp slope factor for predicting the longitudinal temperature decay in the main tunnel and the ramp.

中文翻译：

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匝道坡度对分叉隧道火灾行为影响的试验研究

摘要 为研究自然通风条件下坡道坡度对乙醇池火灾火灾行为的影响，在模型分叉隧道中进行了一系列规模化火灾试验。三个燃料区域的四个斜坡斜率分别为 0%、3%、6% 和 9%。测量并分析了主隧道最高顶板温度和沿水平主隧道顶板和匝道的纵向温度衰减。结果表明，随着坡道坡度的增加，主隧道最高顶棚温度升高，这主要是由于进风量增加导致顶棚火焰增多、燃烧速度增加和热量积累增强的综合作用。此外，根据目前的实验结果，提出了两种考虑斜坡斜率影响的修正模型。坡道顶板纵向温度衰减受坡度的影响，而坡道坡度对主隧道纵向温度衰减的影响相对较弱。此外，然后根据指数函数提出经验相关性，以包括用于预测主隧道和匝道纵向温度衰减的匝道斜率因子。