• 한국방재학회:학술대회논문집
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• 2007.02a
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• pp.250-253
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• 2007

The purpose of this research is focussed on the numerical predictions of the heat and smoke propagations for a passenger train fire in an underground subway tunnel for different air supply and extraction flowrates. The analysis is performed for one of the stations on subway line #5 in Seoul under the emergency operation mode for different air supply and extraction flowrates. Five different the air supply and extraction flowrates are considered for the numerical analyses. The numerical results show that the air supply and extraction flowrates affect the smoke control performance significantly by improving the smoke removal performance for the balanced control of air supply and smoke extraction and for the unbalanced control with lager smoke extraction than air supply.

• Journal of Environmental Health Sciences
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• v.15 no.2
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• pp.1-9
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• 1989

A pilot study was conducted in order to measure indoor and outdoor formaldehyde levels during August 3 - 22, 1988 in several underground spaces in Seoul. Formaldehyde concentrations were monitored during 1 week in selected sampling areas (subway station, underground shopping center, underpass, tunnel, underground parking lot) using passive formaldehyde monitors. In order to investigate a relationship between respiratory prevalence and levels of formaldehyde, each subject was asked to answer respiratory questions. The mean formaldehyde concentrations were 60.1 ppb in subway station, 122.2 ppb in underground shopping stores, 72.1 ppb in underpasses, 39.7 ppb in tunnel, and 75.9 ppb in underground parking lots, respectively. The mean indoor formaldehyde concentrations in underground environments varied from 28.6 ppb to 118.7 ppb. Generally, the mean formaldehyde concentrations in ticketing office in subway stations appeared higher than those level measured in platform. The mean formaldehyde concentrations of underground shopping center in Gangnam Terminal were higher than any other areas and it exceeded 100 ppb of the American Ambient Air Quality Standards of formaldehyde. Prevalence rates of respiratory symptoms of dwellers seemed to be related to higher indoor formaldehyde levels.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.523-528
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• 2011

Subway becomes more and more main transportation in major cities. Air pollution in the subway platforms is decreased; however, dust flow inside subway tunnel and train is increased by installing Platform Screen Door. Airflow inside subway tunnel is observed using computational method in this study The airflow characteristics around ventilation shafts and inside the tunnel is studied following the train movement, while the train moves from existing Miasamgeori station to Gireum station ANSYS CFX V12.0.l and ICEM CFD V12.0.l are used to compute the airflow inside the subway tunnel.

• Fire Science and Engineering
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• v.22 no.5
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• pp.1-8
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• 2008

The study is to perform numerical analysis of train fire characteristics in an underground subway tunnel, depending the different locations of ventilation facility. To study the characteristics of train fire, two kinds of worst-case scenarios are selected, based on escape distance, escape time, and fire zone, and trends and thermal environments of tunnel are analyzed by changing the locations of ventilation facility for times. Fire characteristics is calculated by using FLUENT v.6.3.26, and turbulent flow is calculated by using the standard k-${\varepsilon}$ model. The numerical results show distribution of carbon monoxide concentration, temperature, and velocity. The results of this study will contribute to building the most suitable ventilation systems when designing subway stations and tunnels.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.29-50
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• 2002

Based on the investigation results on the damages of some underground structures due to the severe Kobe Earthquake it concludes that the aseismicity of underground is far superior to that of aboveground structures. Therefore, at first, necessity to reconstruct strong cities especially by good use of underground space will be discussed. Then two non-circular shield-tunneling projects in Japan are discussed. The first is construction of the world's first shield driven double track subway tunnel of rectangular shape for the Kyoto Municipal Subway. This paper presents a report on the overall planning, the tests that were performed in the process of planning, and the results of driving. The second is the design of the Hirakata Tunnel, with three traffic lanes and shoulders on one side, which will be constructed as one of the tunnels for The New Meishin (Nagoya-Kobe) Expressways. This paper presents the feasibility study of the shield tunneling method, using the same design criteria as the non-circular, horseshoe section of mountain tunnel, to the equivalent section of the Hirakata Tunnel.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.57-63
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• 2016

Recently, subways in the city are formed a vast underground network which is interfered with construction when large-scale infrastructure will be planned to nearby existing subway tunnels. Researches have been restricted to estimate stability of existing subway tunnel due to adjacent excavation causued by small construction such as buildings. In this paper, OO underpass is planned on the top of existing subway tunnel, which will be need large-scale excavation, is selected as a subject of study. And the purpose of this study is to analyze the effects on existing subway tunnel due to excavation by stages on construction of underpass. The 3D-numerical analysis was performed by using the MIDAS/GTS program. The stability on existing subway tunnel caused by sequential excavation is analysed using numerical results. Based on the analysis, the excavation orders and reinforcement methods was suggested for stability of exiting subway tunnel.

• Particle and aerosol research
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• v.11 no.1
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• pp.21-28
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• 2015

In this study, the flow around a subway train running in an underground tunnel was numerically estimated. For the validation of the numerical results, the airflow velocity at a point underneath a subway train was measured using an ultrasonic anemometer. Then, the trajectories of particles generated at the contact points between the wheels and rails were numerically predicted. By considering the airflow velocity and particle trajectories, the space underneath the T-Car (trailer car) was expected to be appropriate for the room for the installation of a dust-removal system.

• Magazine of korean Tunnelling and Underground Space Association
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• v.13 no.3
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• pp.60-63
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• 2011

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.340-345
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• 2002

Passengers in automobile or train are exposed to a worse noise environment when they are in the tunnel than in the open field. This is due to a relatively higher space density of sound energy by multiple reflection phenomenon of noise generated by operation of transportation vehicles from tunnel wall compared to open field. In this study, noise characteristics of subway train running through a tunnel were investigated at straight/curved track and tunnel type(semi circular/box). Also the noise measured simultaneously at inner and outer sides of train running through a tunnel, so that the coherence of the various noise sources of subway train to inner noise was evaluated.

• Tunnel and Underground Space
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• v.3 no.2
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• pp.118-131
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• 1993

In this study, the results of elasto-plastic analysis for a subway tunnel using finite element method are presented. To determine input data for the analysis we carried out rock mass classificaton, insitu test and back analysis using measured displacements. Tunnel convergence, extension of yielding Zone and support load are described. By comparing the results of four different reinforcement patterns, the influence of those patterns on tunnel stability is presented. As a result of the analysis we suggest a ratonal reinforcement pattern.