Study On Smoke Spread Of The Extra-long Highway Running Tunnel Form Under Longitudinal Ventilation

With the rapid development of tunnel traffic in China, a large number of extra-long highway tunnel. Extra-long highway tunnel as a typical tubular structure limited space, has a narrow space, strong sealing ability, usually low visibility, long in depth, the characteristics of few exports made in the event of fire is easy to cause casualties. The flue gas is one of the main reasons of causing casualties when fire, extra-long highway tunnels in China smoke means at present mainly adopts longitudinal ventilation tunnel segment send row type, so the specially long highway tunnel fire smoke spreading law under the longitudinal ventilation mode and control of tunnel fire prevention and control has important significance. The results for the specially long highway tunnel fire smoke control scheme to provide the theory technical reference.On the basis of previous studies, this paper summarizes the reasons and characteristics of tunnel fire and the damage of highway tunnel fire smoke is introduced the research status at home and abroad; The basic process of tunnel fire are analyzed, and summarizes the tunnel longitudinal ventilation effect on the spread of tunnel fire smoke, contrast different extra-long highway tunnel ventilation form characteristics, introduces the theoretical basis of numerical simulation of highway tunnel fire smoke; A single hole two-way extra-long highway running tunnel in Sichuan as the research object, through field investigation, the research methods of combining theoretical analysis and numerical simulation, first, selecting 500 m length tunnel simulation section, longitudinal ventilation on different fire power the size of the critical wind speed of tunnel fire simulation research, it is concluded that the flue gas movement law; Then select 2500 m length of tunnel fire smoke analysis, numerical simulation of tunnel under different ventilation speed of the spread of fire smoke and temperature field in the tunnel, visibility, oxygen content changes are analyzed. By analyzing the simulation results, it is concluded that the specially long highway tunnel fire under different fire power ventilation size, the critical wind speed and different fire power for highway tunnel longitudinal ventilation size spread of fire smoke control effect, the research results can provide the type of extra-long highway tunnel fire smoke control and rescue plan formulation to provide theoretical reference basis.