Smoke spread characteristic in immersed tube tunnel fire

This paper analyzed the fire smoke spread in immersed tube tunnel, established smoke movement control equation, and derived the theoretical model for predicting the smoke layer temperature and velocity decay in the longitudinal direction in tunnel fires. On this basis, taking Hongkong-Zhuhai-Macao immersed tube tunnel as the research subject, this paper carried out full-scale tunnel fire test, verified the forecasting model of mean temperature and mean spread speed of smoke layer under the condition of different heat release rate and longitudinal wind. The results show that when the entrainment effect of the smoke layer on ambient air is ignored, an exponential decay model of the smoke layer temperature and velocity can be found; meanwhile, the smoke velocity varies with the change of smoke temperature. Finally, the smoke movement prediction model of Hongkong-Zhuhai-Macao immersed tube tunnel fire is proposed.