• Magazine of korean Tunnelling and Underground Space Association
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• v.12 no.4
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• pp.13-27
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• 2010

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1994.03a
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• pp.1-11
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• 1994

현재 국내 터널의 설계와 시공은 대부분 NATM의 원리를 적용하고 있다. 그러나 터널의 설계 접근방법과 시공의 상황을 살펴보면 NATM을 국내 지질에 적용하는 것이 항상 최적이 아니라는 것을 알수 있으며, 국내 터널의 시공에 있어서도 NATM과 다른 개념의 도입과 정확한 이해가 필요하다는 것을 많은 기술자가 느끼고 있다. 따라서 보다 경제적이고 안전한 터널 시공방법의 결정을 위해 NATM의 개념과 다른 터널 설계 및 시공방법으로 노르웨이 터널 시공법(Norwegian Method of Tunnelling, NMT)을 소개하고자 한다. (중략)

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.4
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• pp.28-36
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• 2024

In this study, an analytical evaluation of evacuation safety in typical road tunnels was conducted. The Fire Dynamics Simulator (FDS) was employed to perform fire simulations with varying fire sizes to determine the allowable evacuation time in road tunnels. Additionally, evacuation simulations were performed using Pathfinder, considering the width of barrier doors and the spacing of evacuation passageways, to calculate the required evacuation time. A comparison between the allowable and required evacuation times was conducted to assess the impact of fire size, passageway spacing, and barrier door width on tunnel evacuation safety. The results from the fire and evacuation simulations indicated that an increase in fire size and passageway spacing, along with a decrease in door width, resulted in an increase in the number of casualties. Conversely, increasing the barrier door width to more than 1.2meters led to a reduction in casualties as passageway spacing increased.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.2
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• pp.113-128
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• 2024

Items of road tunnel PISD (Precise Inspection for Safety and Diagnosis) were reviewed and analyzed using newly enhanced MMS (Mobile Mapping System) technology. Possible items with MMS can be visual inspection, survey and non-destructive test, structural analysis, and maintenance plan. The resolution of 3D point cloud decreased when the vehicle speed of MMS is too fast while the calibration error increased when it is too slow. The speed measurement of 50 km/h is determined to be effective in this study. Although image resolution by MMS has a limit to evaluating the width of crack with high precision, it can be used as data to identify the status of facilities in the tunnel and determine whether they meet disaster prevention management code of tunnel. 3D point cloud with MMS can be applicable for matching of cross-section and also possible for the variation of longitudinal survey, which can intuitively check vehicle clearance throughout the road tunnel. Compared with the measurement of current PISD, number of test and location of survey is randomly sampled, the continuous measurement with MMS for environment condition can be effective and meaningful for precise estimation in various analysis.

• 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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• 2012.04a
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• pp.428-431
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• 2012

본 연구에서는 터널 화재 시 보다나은 대피 안전성확보를 위해 2차적 사고예방에 목적을 둔 정보표지판(Variable Message Sign)을 제연막으로 활용함으로써 터널 대피자의 안전성을 확보하고 대피취약자로 하여금 충분한 대피시간의 확보를 위한 최적의 조건을 제시하고자 하였다. 정보표지판의 다양한 설치 조건에 따라 화재연기가 전파되어지는 거리를 화재 시뮬레이션인 FLUENT와 피난 시뮬레이션인 SIMULEX를 이용하여 통근자와 고령자의 안전거리를 비교하고 대피 안전성을 검토하였다.

• Tunnel and Underground Space
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• v.15 no.6 s.59
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• pp.432-440
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• 2005

Baehuryeong tunnel connects Chuncheon with Hwacheon in Kangwon, Korea, This tunnel is a single tunnel with 5,057 m long and two bidirectional lanes which will be extended into low lanes in the future. The estimated construction period of Baehuryeong tunnel is approximately 55 months. This tunnel will become the longest bidirectional roadway tunnel in Korea. Compared to a twin tunnel, a bidirectional single tunnel has two major disadvantages with regard to the ventilation system and ease of escape during fire. For these reasons, a service tunnel and the transverse ventilation system are planned first time in Korea. In case of fire, the tunnel ventilation design aims to maintain a smoke free layer for passenger evacuation. The geology of Baehuryeong tunnel site is mainly composed of gneiss and granite. Baehuryeong fault is a mainly large scale fault which stands vertical and parallels with tunnel direction. The influenced zone of this fault is within 70 m. Baehuryeong tunnel was designed that it was separated with the distance of more than 100 m from Baehuryeong fault for its safety.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.13-20
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• 2011

The main objective of this paper is finding the influence factors and their degree of importance to steel liner's safety by investigating and evaluating the buckling incidents of steel tunnel liner under external water pressure. The study was based on the detailed investigation to the design conditions and incident shapes at 2m diameter waterway tunnel with a partially buckled internal steel liner and concrete backfilled lining as the raw water transmission pipe line of regional water supply project. Appropriate buckling theory capable of applying this incident points was selected by referring the existing literature and compared with the results of investigation. Also, hydrogeological characteristics of this site on buckling pressure was evaluated. The result of this study was shown that both the hydrogeological characteristics of upper geologic layers and proper tunnel construction are important factors on buckling at steel liner, and hydraulic gradient level should be decided according to the hydrogeological characteristics. This incident case analysis on steel liner of pressurized waterway tunnel was expected to provide more information for realizing the problems and improvements at each design, construction and maintenance stages.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2007.10a
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• pp.137-146
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• 2007

해저 지하 구조물을 시공할 경우는 높은 수압 및 침투압 등의 영향이 무시될 수 없으므로 지하저장 공동의 정확한 거동평가를 위해서는 수리-역학적 해석이 수행되어야만 한다. 또한, 실무에서는 암반이완하중을 고려하여 터널의 콘크리트 라이닝을 설계하며, 이를 위해 이완하중고를 터널 주변의 국부안전율 분포를 이용하여 수치해석에 의해 산정하는 방법이 제안된바 있다. 따라서 본 연구에서는 해저터널을 대상으로 수리-역학적 연계해석 시 국부안전율을 이용한 이완하중고 산정 기법의 타당성을 살펴보았다. 이를 위해 3등급 암반을 대상으로 숏크리트 수리특성을 이용한 유도배수방법과 집수정의 펌핑을 이용한 유도배수방법을 이용하여 이완하중고를 산정하고 적용성을 비교하였다. 연구 결과 연계해석 시 해저시설물의 안전율 및 이완하중고를 정확하게 산정하기 위해서는 집수정의 펌핑을 이용하여 유도배수하는 모델링 방법이 보다 정확하고 일관성 있는 결과를 얻을 수 있었다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.91-104
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• 2008

In tunnels, safety factor concept has been suggested to estimate their stability quantitatively. It is merely limited in the framework of mechanical analysis. However safety factor concept has not been applied in hydro-mechanical coupled analyses due to their modelling complexity. Recently studies on this topic are being actively made. In this study, induced drainage modelling methods for hydro-mechanical coupled analyses are compared and analyzed to estimate safety factor of a subsea tunnel exactly. To this end, methods both controlling hydraulic characteristic of shotcrete and using a drainage well are considered. Sensitivity analysis were carried out on rock class, thickness of shotcrete, and hydraulic properties of rock mass. As the results of this study, it turned out that the induced drainage modelling using a drainage well would give more reliable results than that of controlling hydraulic characteristic of shotcrete in estimating tunnel stability in hydro-mechanical coupled analyses.