• Tunnel and Underground Space
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• v.20 no.6
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• pp.465-474
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• 2010

Although the number of medium-length road tunnels, less than 1 km in length, has increased recently more than 30 percent each year, their ventilation and fire safety system design guidelines have not been established yet. The guidelines for long tunnel design are adopted even for the medium-length road tunnels. Therefore the necessity is brought up to optimize the ventilation and fire safety systems based on their own design guidelines. This study aims at determining the optimal start time of jet fan in case of 20 MW fires by analyzing smoke backlayering range, temperature distribution, range of poor visibility, evacuation time and critical velocity. The CFD study results are expected to contribute to propose the optimal fan operation mode.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.11a
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• pp.484-489
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• 2008

We carried out a one-way heating experiment on the PC panel manufactured by changing the filling depths(20,30,40,50mm) of concrete regarding the fire strength in order to measure the inner concrete pressure which is a direct cause of concrete spalling. This fire experiment was conducted under the fire strength conditions of ISO 834 Standard, Modified Hydrocarbon and the maximum value of Pore Pressure was measured. As a result of analyzing the time it took to reach maximum pressure, it showed that the time rising to the maximum pressure of high strength concrete of 40MPa is slower than that of a 24MPa tunnel lining. In case of ISO fire conditions, spalling damage might take place in heating period of $20{\sim}40$ minutes in the range of $100{\sim}200^{\circ}C$ temperature. In case of MHC fire conditions, the area damaged by fire can appear after a lapse of $25{\sim}50$ minutes in the range of $150{\sim}250^{\circ}C$ temperature.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.58-69
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• 2010

Turkey Eurasia Tunnel Project is large scale road construction project of which the total length is 14.6km. The subsea shield TBM tunnel will be constructed under Bosphorus strait and the project site is in poor condition as composite ground, high water pressure and earthquake. The design procedure of subsea tunnel was introduced with tender design materials. That procedure contains tunnel type, TBM type and the principal design items considering geological condition such as high water pressure, composite ground and seismic area. This paper states the progress for geotechnical investigation, seismic analysis and TBM tunnel design. Analysis for geotechnical investigation is in progress, aseismatic design is going on stability study for liquefaction and structure. In addition, the performance of shield TBM to be considered such as advance rate and improvement of TBM was reviewed. The plan of fire safety was also reviewed with respect to fire protection.

• Fire Science and Engineering
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• v.30 no.2
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• pp.75-80
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• 2016

In the wake of expanding and overpopulating urban areas, traffic congestion has been worsening increasingly, causing huge economic losses. In a bid to effectively use the space of metropolitan areas, the construction and operation of a double deck tunnel has been on the rise. On the other hand, a lower height of a double deck tunnel is expected to generate more smoke and soot in a fire than other usual tunnels. Therefore, it is undesirable to apply the standard for fire intensity or smoke generation, which were designed for existing road tunnels. A part of an effort to propose a design fire curve that is useful for double deck tunnel, is intended to obtain and analyze the fire characteristics in a double deck tunnel through a real scale fire test. The test was conducted according to the fire scenario with one passenger car and two passenger cars; the monitored fire intensity was a maximum of 2.4 MW and 3.5 MW, respectively.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.11a
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• pp.369-374
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• 2007

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.3
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• pp.186-192
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• 2009

In this study it is intended to review the moving characteristics of smoke by performing visualization for calculation of the optimal smoke exhaust air volume in case a fire occurs in tunnels where transverse ventilation is applied, and to obtain basic data necessary for design of the smoke exhaust systems by deriving optimal smoke exhaust operational conditions under various conditions. As a result of this study, if it was assumed 0 critical velocity in the tunnel, the smoke exhaust air volume was limited within 250 meter in the road-tunnel disaster prevention indicator and the exhaust efficiency was from 55.1% to 95.8% in the result of this study. In case of oversized exhaust ports, the generated smoke is more than the case of uniform exhaust. When the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173\;m^3/s$, $236\;m^3/s$ for the distance of the moving smoke which can limit the distance to 250 m.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.167-175
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• 2019

To effectively deal with the fire in tunnel which is mostly the vehicle fire, it's more important to suppress the fire at early stage. In urban tunnel, however, accessibility to the scene of fire by the fire fighter is very limited due to severe traffic congestion which causes the difficulty with firefighting activity in timely manner and such a problem would be further worsened in underground road (double-deck tunnel) which has been increasingly extended and deepened. In preparation for the disaster in Korea, the range of life safety facilities for installation is defined based on category of the extension and fire protection referring to risk hazard index which is determined depending on tunnel length and conditions, and particularly to directly deal with the tunnel fire, fire extinguisher, indoor hydrant and sprinkler are designated as the mandatory facilities depending on category. But such fire extinguishing installations are found inappropriate functionally and technically and thus the measure to improve the system needs to be taken. Particularly in a double-deck tunnel which accommodates the traffic in both directions within a single tunnel of which section is divided by intermediate slab, the facility or the system which functions more rapidly and effectively is more than important. This study, thus, is intended to supplement the problems with existing tunnel life safety system (fire extinguishing) and develop the remote-controlled automatic fire extinguishing system which is optimized for a double-deck tunnel. Consequently, the system considering low floor height and extended length as well as indoor hydrant for a wide range of use have been developed together with the performance verification and the process for commercialization before applying to the tunnel is underway now.

• Fire Science and Engineering
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• v.22 no.3
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• pp.221-227
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• 2008

In this study, the fire suppression characteristics of a water mist with natural wind in a road tunnel were calculated using the FDS(Fire Dynamic Simulation) code. In addition, the cooling and the chemical kinetic effects of water vapor on fire extinction ere investigated in a counterflow non-premixed flame using a detailed chemistry. As a result, the behavior of fire plume and the spray characteristics of water mist are modified remarkably with the increasing of wind velocity. In the case which is not the external natural wind, small droplets are more efficient in fire suppression than large droplets. However, the large droplets show better results on the fire suppression than the small droplets with the increasing of wind velocity. It can be estimated that the natural wind disturb the penetration of water droplets into the flame region and decrease the effect of oxygen dilution. Finally, it can be identified that the fire into the natural wind can be suppressed with smaller amount of $H_2O$ by flame stretching effect in the flame region than one in an enclosure, and the chemical kinetic effects of $H_2O$ on fire extinction are not affected significantly the velocity of natural wind.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.225-234
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• 2018

Domestic urban areas are experiencing serious traffic congestion problems due to continuous population growth and increased traffic volume. In order to solve the problem of traffic congestion, the study of great depth underground double deck tunnels using underground space is being actively carried out in the urban areas. The characteristics of great depth underground double deck tunnels are low in cross section, so the spread of fire smoke is expected to spread faster than the road tunnel in case of fire. Therefore, it is necessary to provide a fire smoke delay device which delays the spread of fire smoke when a fire occurs in a tunnels. In the previous study, the diffusion effect was analyzed according to the blocking area when the fire smoke spread delay device was operated through the 3D CFD in the study of preventing the smoke spread in the case of the tunnel fire. A study on fire smoke diffusion delay device using spring elasticity which is excellent in applicability to a tunnel and economical value is studied. In this study, fire smoke spread delay system was developed to fire smoke delay was experimentally analyzed. Fire smoke delay effect of fire smoke delay device appeared. Therefore, it is considered that the can minimize the damage of the victims when installed in the great depth underground double deck tunnels.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1244-1250
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• 2009

In this study it is intended to review the moving characteristics of smoke by performing visualization for the calculation of the optimal smoke exhaust air volume in case a fire occurs in tunnels where transverse ventilation is applied, and to obtain basic data necessary for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions under various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173\;m^3/s$, $236\;m^3/s$ for the distance of the smoke moving which can limit the distance to 250m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.