城市隧道火灾烟气最高温升特性的全尺寸试验研究

Full Scale Tests on the Maximum Smoke Temperature Rise in an Urban Tunnel

通过在城市隧道中开展全尺寸火灾试验,研究了隧道顶棚射流烟气最高温升沿纵向的衰减规律,并对现有的火源区顶棚下方最高温升预测模型进行了验证。结果表明,隧道坡度对烟气最高温升的纵向衰减趋势有重要影响,沿上坡方向衰减较慢,而沿下坡方向衰减更快。通过试验数据进行非线性拟合,获得了类似于Alpert模型的最高温升幂函数衰减模型。对于火源区顶棚下方的最高温升,Li模型与试验测量值之间的误差更小,其预测精度比Kurioka模型更高。

This work investigated the longitudinal decaying behavior of maximum smoke temperature rises in an urban tunnel by conducting 5 full scale fire tests.It also verified the prediction accuracy for existing models on the maximum gas temperatures beneath the ceiling in the fire region.Results showed that tunnel grade demonstrated significant influence on the longitudinal decaying behavior,i.e.temperatures decayed faster in the down-grade direction than in the up-grade direction.Longitudinal decaying models were established by non-linear regression analysis based on the Alpert model.It was also found that,for the maximum gas temperatures in the fire region,discrepancy between the Li model predictions and the measured values was relatively small,which indicated higher accuracy than the Kurioka model.