Study on smoke temperature distribution based on model test in highway tunnel by shaft blow and exhaust ventilation

To investigate the maximum temperature along tunnel ceiling and temperature distribution properties at different height of tunnel center line, a series of fire tests under the longitudinal ventilation by the blowing and exhausting shaft were conducted in a 1:50 small scale model tunnel. The results show that the fan switching state has an obvious impact on the maximum temperature along tunnel ceiling; when the fire occurs in short section, the temperature of each measure point on 1# thermo element tree rises successively from top to bottom under normal operation, and the temperature are overall lower, but the temperature situation is opposite under the condition that part of fans is off. Under shutdown condition, the smoke doesn't sink to the bottom of 3# thermo element tree; when fire occurs near tunnel entrance, the transfer capacity of fire heat decreased downward slightly under shutdown condition; when fire occurs near tunnel exit, the temperature characteristics of each point on 1# thermo element tree is in poor regularity, but that is good under shutdown condition. The axial fan to supply wind has the greater influence on smoke movement; Based on the temperature distribution and the smoke rule observed in tests, the effective airflow organization is suggested for fire fighting in Fenshuiling tunnel. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.