Abstract:

The fire smoke control in tunnels with different slope shapes is difficult. The characteristics of fire smoke temperature distribution in tunnel with different slope shape are studied by 3D numerical simulation methods taking fire smoke ventilation of Vshaped slope of Weihe Tunnel on BaojiLanzhou passengerdedicated railway for example. The fire cases of Vshaped slope, oneway slope and convex slope under different longitudinal ventilation velocities are simulated; and the characteristics of temperature at tunnel crown top, 1.5 m point (from inner rail top) and 3.0 m point (from inner rail top) are analyzed and compared. The results show that: 1) The temperature around summit of convex slope is the highest without longitudinal ventilation at early fire; the temperature dropping velocity of fire smoke in Vshaped slope tunnel is the smallest with the distance away from fire source increases. 2) The temperature along the lower reaches of Vshaped slope tunnel is higher than those of oneway slope tunnel and convex slope tunnel under longitudinal ventilation; the scope of maximum temperature zone of Vshaped slope tunnel increases with ventilation velocity increases; the temperature variation rules of oneway slope tunnel and convex slope tunnel are almost the same. 3) The fire smoke control effect can reach best when longitudinal ventilation velocity reaches 2 m/s in case study.

Key words: passengerdedicated railway line, tunnel fire, Vshaped slope, smoke temperature, longitudinal ventilation