• Proceedings of the KSR Conference
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• 2004.10a
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• pp.880-885
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• 2004

When a fire takes place, the escape tunnel which could prevent passengers and the crew from disasters would be most important facility among railway tunnel facilities for prevention of disaster. A shorter space between the escape tunnels is much better for safety because of short escape time. The establishment of short space escape tunnels(driftways) in the single track parallel tunnel is much easier. The establishment of long space escape tunnels(inclined shafts, vertical shafts) in the double track is much more advantageous economically. We, therefore, compared the movement time of smog originated from fire with the escape time of the crew and passengers for setting up the best space between the escape tunnels in the double track tunnel. We could calculate the best space between the escape tunnels in the double track tunnel properly by computer simulation.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.483-488
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• 2009

When a train enters into the tunnel with high speed, a compression wave generated inside the tunnel has been studied as a one-dimensional phenomenon. However, one-dimensional approach can't analyze 3-dimensional flow effect in the vicinity of the train body. In this research, so as to overcome this weak point, a prediction method of the wavefront of a compression wave using steady state solution has been used for the parametric study considering 3-dimensional effects of the interactions between trains and tunnels. The effective hood shapes were deduced in both cases of the train's entry into the tunnel on the single track and on a side of the double track. As a result, in case of the train's entry on a side of the double track, the increase of compression wave value propagated to the tunnel inside have appeared compared with the train's entry on the single track. Also, a horizontally convex elliptic hood shape is more effective at the train's entry on a side of the double track for the purpose of a decrease of wavefront gradient of a compression wave.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1998-2004
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• 2003

Numerical study were performed to analyze for fire safety in railway tunnel with forced ventilation vents. For the condition of train fires with heat release rate of 30 MW, unsteady three dimensional analysis were carried out to investigate the effects of smoke movements, the heat transfer and $CO_2$ concentrations and in double track tunnel with two vents. Among three operation modes of forced ventilations at two vents, the exhaust-exhaust mode of the vent represents the best performance for the evacuation of passengers to avoid the fire.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.117-124
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• 2000

This paper presents the construction planning and the detail design of a 16.2 km long railroad tunnel in a mountainous area. Major design conditions for railroad are the single track, loop-typed alinement, and a maximum grade of 24.5$\textperthousand$. A underground station(double track) with a length of 1.1km is located in the middle of the line for train cross-passing. Tunnel is excavated in highly complex geological conditions including faulted areas, abandoned mine works areas, and various rock types such as sandstone, shale, limestone, and coal seam partly. Drilling and blasting method was adopted because it is more flexible than TBM(Tunnel Boring Machine) as a result of risk assessment for geological conditions in this area. Two working adits were planned to adjust the construction schedule and can be used for ventilation and maintenance in operation phase. New material and concept were introduced to the tunnel drain design. They are expected to improve tunnel drain condition and capability. Rational tunnel support design was tried to consider the various tunnel size and purpose and to use the geological investigation results.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.127-132
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• 2004

The third double-track construction part of work, called Chung Ang Railroad line(Deok-So$\∼$Won-Ju) is in progress and the personal museum located 330m from the starting point of Pal-Dang Tunnel(length=4,470m) line in the canyon is to be effected by rock blasting during the tunnel excavation work, especially museum articles and building itself. This paper is the example of application suitable tunnel rock blasting pattern for excavation after the case study about the investigation and analysis of rock blasting noise pollution during tunnel excavation work. The museum is a three-story building, RC concrete structure and is located 17m from the top of the tunnel, in the center of the double-track line. Comparing estimate vibration frequency with site vibration one, it can be verified the reasonable rock blasting noise pollution as improving the application of tunnel excavation rock blasting pattern. The above pattern has been selected economically and effectively and applied to our construction field.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.371-376
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• 2007

This paper describes a study to determine proper escape way interval for the design phase of single bored double track tunnel. Among many methods which determine escape way interval, we choose a QRA(Quantitative Risk Analysis) method. But a different method must be chosen differ from other country because of special design situation of Korea. So, it is necessary to develop a method which considers a special design condition of Korea. Because fire accidents of railway tunnel are a rare event, simulated situation can be produced by CFD simulation and evacuation analysis simulation. However, it is generally difficult to estimate of fatalities from these methods, so a concept of FED is introduced to estimate of fatalities. Quantification process provides effective results for practical design stage and the result were employed in design.

• Wind and Structures
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• v.35 no.4
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• pp.269-285
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• 2022

The pressure-mitigating effects of a high-speed train passing through a tunnel with a partially reduced cross-section are investigated via the numerical approach. A compressible, three-dimensional RNG k-ε turbulence model and a hybrid mesh strategy are adopted to reproduce that event, which is validated by the moving model test. Three step-like tunnel forms and two additional transitions at the tunnel junction are proposed and their aerodynamic performance is compared and scrutinized with a constant cross-sectional tunnel as the benchmark. The results show that the tunnel step is unrelated to the pressure mitigation effects since the case of a double-step tunnel has no advantage in comparison to a single-step tunnel, but the excavated volume is an essential matter. The pressure peaks are reduced at different levels along with the increase of the excavated earth volume and the peaks are either fitted with power or logarithmic function relationships. In addition, the Arc and Oblique-transitions have very limited gaps, and their pressure curves are identical to each other, whereas the Rec-transition leads to relatively lower pressure peaks in C_Pmax, C_Pmin, and ΔC_P, with 5.2%, 4.0%, and 4.1% relieved compared with Oblique-transition. This study could provide guidance for the design of the novel railway tunnel.

• Journal of environmental and Sanitary engineering
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• v.15 no.4
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• pp.134-141
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• 2000

The person' spending time in underground s[aces within indoor environment show a tendency to increase every year, but in Korea, levels and sources of pollutant in underground spaces have not been well-characterized. Therefore, as part or a larger indoor environmental study, conducted at subway station in Seoul, nitrogen dioxide was measured using passive samplers in 16 subway stations, 2 tunnels and 70 workers of subway station. The mean concentrations of nitrogen dioxide in subway stations were $27.87{\pm}7.15$ ppb at station office, $35.76{\pm}8.35$ ppb at platform, $52.60{\pm}13.04$ ppb at outdoor, respectively, and the Indoor/Outdoor ratio were 0.49~0.93. The mean concentrations of nitrogen dioxide in tunnels were $44.91{\pm}4.67$ ppb in Chunggye-Nowon tunnel with a single track, $42.55{\pm}3.33$ ppb in Mokkol-Taenung tunnel with double track, respectively, and as a result of t-test, a single track levels were higher than double track levels(p<0.05). The mean personal exposure of the subject of station workers was $29.40{\pm}9.75$ ppb.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.249-256
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• 2015

Quantitative Mokpo-Jeju undersea tunnel is currently on the basis plan for reviewing validation. As for the cross section shape for express boat of 105 km line, sing track two tube is being reviewed as the Euro tunnel equipped with service tunnel. Also, 10 carriage trains have been planned to operate 76 times for one way a day. So, in this study, quantitative risk assessment method is settled, which is intended to review the optimal space between evacuation connection hall of tunnel by quantitative risk analysis method. In addition to this, optimal evacuation connection hall space is calculated by the types of cross section, which are Type 3 (double track single tube), Type 1 (sing track two tube), and Type 2 (separating double track on tube with partition). As a result, cross section of Type 2 is most efficient for securing evacuation safety, and the evacuation connection space is required for 350 m in Type 1, 400 m in Type 2, and 1,500 m in Type3 to satisfy current domestic social risk assessment standard.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.03a
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• pp.323-330
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• 1999

Daylight collapse have been occurred by about 5.0m deep at ground surface and collapse of the crown head part of the tunnel have connected to the ground surface during first step of shotcrete work after blasting of upper half section of the tunnel driving at two-way double track tunnel face section on highway construction. This study is for a successful illustration case for the earth improvement method through applying such strengthening methods as cement milk grouting, S.G.R grouting,, steel pipe reinforced multi-step grouting etc. for the purpose of earth strengthening of loosened earth block occurred by tunnel collapse.