The Research On The Exhausting Fume Method Under Conflagration In The Extraordinary Long Highway Tunnel With Segmenting Lengthways

The aim of this study is to investigate the new method of exhausting fume under conflagration in the extraordinary long highway tunnel with segmenting lengthways ventilation. Firstly, we reviewed the developing course and current situation of ventilated modus of highway tunnel in China and foreign countries, the investigative situation of conflagration and exhausting fume in tunnel in different countries, and the problems needed to be solved. Secondly, we analyzed the category of conflagration in highway tunnel, built the physical-mathematic ventilative model under conflagration, and further derived and analyzed the corresponding theoretical formulas on ventilative calculation in tunnel. The diffusing regularity of temperature, pressure and smoke under tunnel conflagration was investigated. The resistance of smoke flow in conflagration was also evaluated.Finally, we proposed the segmenting lengthways plus in conflagration which was a new exhausting fume method in extraordinary long highway tunnel. The limited dimension analysis of this novel method had been done. The results of analysis showed that compared with traditional methods, in areas 150 meter away from fire, the temperature would decrease 26% and the exhausting fume flow rate would increase 15% under new exhausting fume method. The comparative results hinted that for the sake of economy and technique, the recommended portait interval of half transversal exhausting fume bouche was 25 meter. We suggested that when the distance of each ventilative slope cenote is more than 3 kilometer, the design of exhausting fume suspended ceiling should be considered in extraordinary long highway tunnel.