Experimental study on critical ventilation speed in asymmetric herringbone tunnel fire
Herringbone tunnels are often found in mountain tun-nels and new-built urban traffic tunnels.The smoke flow is com-plicated in case of fire and controlling the smoke effectively with longitudinal ventilation is relatively difficult.By setting up a 1:20 herringbone tunnel model test rig,the critical ventilation speed un-der different slope composition and different fire power in asym-metric herringbone tunnel was studied.The results show that when the longitudinal ventilation flows from the small slope side to the large slop side,the critical ventilation speed is greater than that in the normal tunnel with the same tunnel cross-section and same fire power.The critical ventilation speed increases with the increase of the slope difference on both sides of the variable slope point.When longitudinal ventilation flow from large slope side,the critical ventilation speed is less than that in the normal tunnel,and the critical ventilation speed decreases with the increase of the slope difference.For the engineering application,the slope correc-tion of the critical ventilation speed model of the normal tunnel is carried out based on the experimental results,and the correction coefficient of the critical ventilation speed is obtained.
万方数据
维普
