• Tunnel and Underground Space
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• v.7 no.2
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• pp.100-107
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• 1997

In case of a fire outbreak in a uni-directional road tunnel, the flow of traffic immediately behind the fire disaster will be stalled all the way back to the entrance of the tunnel. Furthermore, when the vehicle passengers try to flee away from the fire toward the entrance of the tunnel, the extremely hot fume that propagates in the same direction will be fatal to the multitudes evacuating, but may also cause damage to the ventilation equipments and the vehicles, compounding the evacuation process. This paper will present the 3-dimensional modelling analysis of the preventive measures of such a fume propagation in the same direction as the evacuating passengers. For the analysis, the fire hazard was assumed to be a perfect combustion of methane gas injected through the 1 m X 2 m nozzle in the middle of the tunnel, and the product of $CO_2$ as the indicator of the fume propagation. From the research results, when the fire hazard occurred in middle of the 400 m road tunnel, the air density decreased around the fire point, and the maximum temperatures were 996 K and 499 K at 210 m and 350 m locations, respectively, 60 seconds after fire disaster occurred, when the fumes were driven out only towards the exit-direction of the tunnel. By tracing the increase of $CO_2$ level over 1% mole fraction, the minimum longitudinal ventilation velocity was found to be 2.40 m/sec. Furthermore, through Analysis of the temperature distribution graphs, and observation of the cross-sectional distribution of $CO_2$ over 1% mole fraction, it was found that the fume did not mix with the air, but rather moved far in a laminar flow towards exit of the tunnel.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.163-167
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• 2008

In this study, the 1/35 reduced-scale model experiment were conducted to investigate designed ventilation effect on the smoke movement at rescue station fire in railway tunnel. A model tunnel with 2 mm thick, 10 m long, 0.19 m high and 0.26 m was made by using Froude number scaling law. The cross-passages installing escape door at the center were connected between incident tunnel and rescue tunnel. The n-heptane pool fires with heat release rate 698.97W were used as fire source. The fire source was located at the center and portal of incident tunnel as worst case. A operating ventilation system extracted smoke amount of 0.015 cms(cubic meters per second). The smoke temperature and CO gas concentration in cross-passage were measured to verify designed ventilation system. The result showed that, at center fire case without ventilation, smoke did not propagate to rescues station. In portal fire case, smoke spreaded to rescues station without ventilation. But smoke did not propagated to rescues station with designed ventilation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.551-555
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• 2009

This study is performed to apply a standard to evaluate fire protection assessment for tunnel structures when a fire breaks out in the road tunnel. Recently, a number of road tunnels have been rapidly increased and fire risk also multiplyed according to extend tunnel length, due to natural features and environmentally-friendly road construction in Korea. But we have not yet been prescribed appropriate time-temperature curve for tunnel fire. Therefore, we presented fire design model and investigated time-temperature curve proposed by a foreign country considering traffic, a kinds of vehicles which are a basis of heat rate. At the end, Hydrocarbon modified curve applied as design fire model by using numerical analysis and presented design fire model and examined the effects of tunnel structures.

• Journal of the Korea Safety Management & Science
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• v.14 no.3
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• pp.67-75
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• 2012

Because recently(July 14, 2011) fire occurred in the engine room of a moving taxi under Namsan Tunnel 1, 51 vehicles' driver and more than 250 passengers in the road tunnel were urgently evacuated with abandoned vehicles. Vehicle fires in Namsan Tunnel that day, Sufferers struggled to escape quickly difficult to escape the two-way by abandoned vehicles on the road and to fear many casualties by using vehicle fuel and combustible interior and the driver who is ignorant of vehicle accident continuous entered in the road tunnel had accessibility the site of fire department was more difficult. In this study, It is to investigate structure and basic materials, such as fire extinguish equipment and facilities for damage prevention and to analyze the problems and to plan improvement method of fire extinguish equipment, facilities for damage prevention and transportation facilities(Large traffic signs, Breaker, etc.) on the Namsan Tunnel that in the long-term plan is prepared to strengthen for accessibility of the site of fire department in case of Vehicle's fire.

• Structural Engineering and Mechanics
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• v.80 no.6
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• pp.701-709
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• 2021

The paper aims at improving the understanding and mitigating the effects of tunnel fires that may breakout due to the burning fuel and/or explosion within the tunnel. This study particularly focuses on the behavior of the commonly used horse shoe geometry of tunnel systems. The problem has been obtained using an adequate well-established program incorporating the Lagrangian approach. A transient-thermo-coupled static structural analysis is carried out. The effects of radiation and convection to the outer walls of the tunnel is studied. The paper also presents the impact of the hazard on the structural integrity of the tunnel. A methodology is proposed to study the tunnel fire using a model which uses equivalent steel sheet to represent the presence of reinforcements to improve the computational efficiency with adequate validation. A parametric study has been carried out and the effect of suitable lining property for mitigating the fire hazard is arrived at. Detailed analysis is done for the threshold limits of the properties of the lining material to check if it is acceptable in all aspects for the integrity of the tunnel. The study may prove useful for developing insights for ensuring tunnel fire safety. To conduct such studies experimentally are tremendously costly but are required to gain confidence. But, scaled models, as well as loading and testing conditions, cannot be studied by many trials experimentally as the cost will shoot up sharply. In this context, the results obtained from such computational studies with a feasible variation of various combinations of parameters may act as a set of guidelines to freeze the adequate combination of various parameters to conduct one or two costly experiments for confidence building.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.115-120
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• 2003

In this study, smoke movement in tunnel fires was investigated with various aspect ratio(0.5, 0.667, 1.0, 1.5, 2.0) of tunnel cross section. Reduced-scale experiments were carried out under the Froude scaling using 8.27 kW ethanol pool fire. Temperatures were measured under the ceiling and vertical direction along the center of the tunnel. Smoke front velocity and temperature decrease rate were reduced as higher aspect ratio of the tunnel cross-section. Smoke movement was evaluated by analysis of vertical temperature distribution 3 m downstream from the fire source. Elevation of smoke interface according to N percent rule was under about 60% of tunnel height.

• Journal of computational fluids engineering
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• v.10 no.1
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• pp.94-98
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• 2005

Accurate prediction of the fire-induced air velocity, temperature and smoke flow in underground utility tunnel becomes more important for the optimization of design and placement of heat and smoke detectors. In order to improve the safety of underground utility tunnel systems, the behaviors of fire-induced smoke flow and temperature distributions are investigated. Especially, two different cross-sectional shapes of tunnel, such as rectangular and circular types are modeled. Also, fire source is modeled as a volumetric heat source. Three-dimensional thermal-flow characteristics in an underground tunnel are solved by means of FVM using SIMPLE algorithm. The effects of shape geometry on the fire-induced flow characteristics are graphically depicted. It is desirable that heat and smoke detectors are installed on the cables and the top of the wall.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.69-75
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• 2013

Namsan road are taxis in the engine room fires (07/14/2011 18:05) in the tunnel, and the driver of the vehicle was 100 passenger car and more than 500 evacuated were disasters. Pole road vehicles within the tunnel if there is a fire tunnel fire occurred at a two-way evacuation difficult and rapid evacuation is difficult and mass casualties are concerned, the number of casualties is feared. In this study, by considering the problems and improve the Namsan 1,2,3 Tunnel In case of fire, the best disaster response is to come up with ways.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1378-1385
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• 2008

This study is aimed to analyze the flow patterns and thermal characteristics by computer simulation under the variations of fire strength for Daegu-Pahang Yimgo-4th tunnel, from which flow and heat distributions are predicted in the longitudinal tunnel. Though the results of numerical computations, followings are found; one is that the volume flow rate is discontinuously increasing as closer to fire location, and the other is that a critical design to get faster flow rate is required because of existence of backlayer flow for the high fire strength in view of safety for the people in fire of the tunnel.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.207-212
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• 2005

In designing a ventilation system of a road tunnel, a possibility of using the system as a smoke control system in case of a tunnel fire has to be considered. In the present study, a numerical simulation on ventilation system is performed considering jet fan operations and moving traffic. A fire-mode operation by reversing some fan operations in case of a tunnel fire is also simulated. The results show that ventilation operation can control the pollutants effectively, and fire-mode operation can control smoke and temperature effectively to prevent a disaster.