Fire And People Evacuation Research In Long Highway Tunnels With Central Exhaust

In tunnel fire, the most hazardous factor is the large quantities of high -temperature toxic smoke generated from burning, and ventilation is one of the most methods to control smoke propagating and reduce the damage. Currentty, there are two main ventilation modes when tunnel fire occurs: the longitudinal ventilation and central smoke extract, the latter has much better performance than the former on fire safety in theory, therefore, it is necessary to emphasize on the research of central smoke extract.The paper focus on the research of ventlation modes and people evacuation in fire based on a long-sized highway tunnel (7.6 km), and the smoke characteristics in tunnel fire with central smoke extract is analyzed using numerical simulation when the turn-on pattern and range of extraction damper changed. By the research, it finds that it can be effective to restrain the smoke propagation and reduce the calamity using central exhaust.According to the principle of people evacuation, It is easy to get the T_REST (Required Safe Egress Time) and T_ASET (Available Safe Egress Time) with different ventilation modes in tunel fire to research the peculiarity of people evacuation, and by the results, it shows that it is helpful for people to evacuate with central smoke extract while tunnel fire occurs, the results also shows that there is problem which is still effectively unsolved on such as the ventilaed organization and the firet-resi sting of structure when using central smoke extract, so more deeply research it needed.