铁路隧道火灾拱顶附近最高温度预测模型研究

Study on Prediction Model for Maximum Temperature around the Vault of Railway Tunnels on Fire

隧道拱顶下方最高温度是结构防火设计中的一个重要参数,对不同火灾工况下隧道拱顶附近最高温度的变化规律进行数值模拟研究。对比分析网格尺寸对火灾模拟结果的影响,结果显示当网格尺寸为0.1D*时模拟结果比较准确。分析了不同纵向通风风速、不同火源热释放速率及不同火源面到拱顶距离的情况下Kurioka最高温度模型的有效性,得出Kurioka最高温度模型在通风风速较小或不通风情况下是失效的。最后,对模型进行修正,给出一个具有广泛应用的隧道拱顶附近最高温度预测模型。

Because the maximum temperature below the tunnel vault is an important parameter of fire protection structure design,the numerical simulation study on maximum temperature law around the tunnel vault under different fire was carried out. The influence of grid size on the result of imitation was compared and analyzed,it shows that the result is more accurate when the grid size is 0.1 D＊. Based on this,the validities of Kurioka maximum temperature were proved by analyzing longitudinal ventilate speeds,fire sources release speed and different stance between fire sources and vault,which shows that the Kurioka maximum temperature model is invalid under the situation of slow ventilation speed and no ventilation. In view of this,the model was revised and a widely-employed tunnel vault maximum temperature prediction model was provided.