• Fire Science and Engineering
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• v.24 no.4
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• pp.86-91
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• 2010

In event of a tunnel fire, all kinds of equipment can be destroyed in high temperature that can exceed $1300^{\circ}C$, fatal structural demage can be caused by spalling of concrete structural elements. To make matters worse, there is a high possibility of the secondary damage which can lead to the collapse of the shear resisting structure. Accordingly, it is time that we developed the technology to counter fires in connection with the fire-resistant design of a tunnel structure. To secure the reliability of the fire-resistance performance of a tunnel structure, it is necessary to assess the fire's behavior on every structural element exposed to the fire as well as to calculate the tunnel fire intensity and the quantity of heat released. In this study, we drew out the fire damage range of each structural element of a tunnel and the minimum thickness of concrete cover for each fire-resistant material through some actual experiments of fire behavior on the structural elements of a tunnel.

• 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 Korean Tunnelling and Underground Space Association
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• v.16 no.1
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• pp.105-115
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• 2014

A numerical analysis on the smoke behavior and evacuee safety has been performed with computational fluid dynamics. The purpose of this study is to build computational processes for an evacuation and prevention of a fire disaster of a 3 km-length tunnel in Korea. To save computational cost, 1.5 km of the tunnel that can include a few cross-passing tunnels is considered. We are going to assess the fire safety in a road tunnel according to the smoke level, which consists of the smoke density and the height from the floor. The smoke density is obtained in detail from three-dimensional unsteady CFD analysis. To obtain proper temperature distributions on the tunnel wall, one-dimensional conduction equation is considered instead of an adiabatic wall boundary or a constant heat flux. The tunnel considered in this study equips the cross passing tunnels for evacuees every 250 m. The distance is critical in both safety and economy. The more cross passing tunnels, the more safe but the more expensive. Three different jet fan operations can be considered in this study; under- and over-critical velocities for normal traffic condition and 0-velocoty operation for the traffic congestion. The SE (smoke environment) level maps show a smoke environment and an evacuating behavior every moment.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2009.04a
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• pp.235-240
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• 2009

지하에 건설되는 터널은 구조상 반 밀폐적인 특성을 가지고 외부와 차단되어 있기 때문에 화재발생시 연기에 의한 질식의 위험성이 크고 다수의 이용자들이 쉽게 패닉현상에 빠지게 되고 많은 연기와 유독가스에 노출되어 생명의 위협을 받게 된다. 또한 연기와 유독가스 호흡에 의한 체내유입은 인체상의 여러 가지 부작용을 초래하는 등 피해를 가져올 수 있다. 이러한 피해를 예방하고 최소화하기 위해 방재설비를 시설하고 운영하는데 국내의 방재시설에 대한 규정은 지하공간을 관리 관장하는 기관과 용도에 따라 각각 다르게 적용하고 있어 터널관련 방재시설의 변천에 대하여 알아보고 현재의 설치 기준과 문제점을 살펴보았다.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2009.04a
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• pp.45-50
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• 2009

지하에 건설되는 터널은 구조상 반 밀폐적인 특성을 가지고 외부와 차단되어 있기 때문에 화재발생시 연기에 의한 질식의 위험성이 크고 다수의 이용자들이 쉽게 패닉현상에 빠지게 되고 많은 연기와 유독가스에 노출되어 생명의 위협을 받게 된다. 또한 연기와 유독가스 호흡에 의한 체내유입은 인체상의 여러 가지 부작용을 초래하는 등 피해를 가져올 수 있다. 이러한 피해를 예방하고 최소화하기 위해 방재설비를 시설하고 운영하는데 국내의 방재시설에 대한 규정은 지하공간을 관리 관장하는 기관과 용도에 따라 각각 다르게 적용하고 있어 터널관련 방재시설의 변천에 대하여 알아보고 현재의 설치 기준과 문제점을 살펴보았다.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.493-498
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• 2003

In case of slope failure by planted protection is constructed on the slope according to of the choice trend of a recently environmental-friendly countermeasure, there has a limitation about diagnosis and preparation of measure. Also, collapse of tunnel pithead department slope has maximum in construction and countermeasure method of construction choice unlike cut-slope. In this study, analyzed inside circumstance of slope using geophysical exploration for stability analysis and countermeasure inside presentation of tunnel pithead department slope which collapse happens. geophysical exploration used dipole(Dipole-Dipole) method that is based to distribution principle does specific resistance, goes side by side with on-the-spot observation and draws base strength parameter and executed stability analysis, and presented stabilization countermeasure inside of collapse slope on this. I wish to conduce in development and research for use technical development of geophysical exploration technique hereafter by executing geophysical exploration in road collapse spot applying through this study.

• Journal of the Korean Society for Railway
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• v.12 no.1
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• pp.167-174
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• 2009

Due to the travelling of the train with high speed the period of maintenance activities of the ballasted track is coming to be short, and more from the residential area of the ballasted track tunnel circumference the civil appeal is increasing with railroad vibration problem. To reduce the vibration problem and a maintenance cost establishes the ballast mat in the tunnel within part segment. In this study, to estimate the vibration reduction effect of the ballast mat we have done a comparative analysis with the vibration field test by the transit train by at the ballasted track with ballast mat and the standard ballasted track without vibration protection in tunnel.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.713-716
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• 2008

This study is performed to propose a standard to evaluate fire protection assessment for concrete structures during a fire on 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 domestic. 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.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.5
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• pp.115-124
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• 2018

Thermal protection materials (TPMs) are very crucial for the survival of any re-entry space vehicles. One of the systems used for rigorous validation of TPMs is an enhanced Huel type segmented arc-heated plasma wind tunnel. A 0.4 MW class arc-heated plasma wind tunnel has been constructed at Chonbuk National University which is capable of producing high enthalpy supersonic flow. In this paper we have studied the characteristics of plasma flow according to power and mass flow parameters.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.4
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• pp.319-345
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• 2011

In case of tunnels in cold regions, a freeze of groundwater around tunnel may act as a barrier of tunnel drainage in winter, or may cause the inner extrusion of lining. In spite of that, a design of insulation for preventing the frost damage of tunnel lining has not been introduced in Korea, while foreign countries such as Norway and so on have a standard on insulation. In this study, a few freezing cases of road tunnels have been reviewed, and the results show that the freezing protection is necessary. In order to characterize the thermal distribution in the tunnel, following measurements have been performed at Hwa-ak tunnel; the temperature distribution by longitudinal lengths, the internal temperature of lining and the temperature distribution of the ground under pavement. From these measurements, the characteristics of the tunnel's internal temperature distribution due to temperature change in the air has been analyzed. Based on the measurement results on the temperature distribution at Hwa-ak tunnel, thermal flow tests on the rock specimen with and without insulation have been performed in the artificial climate chamber to investigate the performance of the insulation. Also, a number of 3D numerical analyses have been performed to propose appropriate insulation and insulation thicknesses for different conditions, which could prevent the frost damage of tunnel lining. As a result of the numerical analysis, air freezing index of 291$^{\circ}C{\cdot}$ Hr has been suggested as the threshold value for freezing criteria of groundwater behind the tunnel lining.