• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.637-644
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• 2016

This paper is a follow-up to previous papers entitled, "Development of Tunnel-Environment Monitoring System and Its Installation" I [1] and II [2]. The target tunnel of these studies is the Solan Tunnel, which is a loop-type, single-track, 16.7-km-long tunnel located in mountainous terrain and passing through the Baekdudaegan mountain range. It is an ordinary railway tunnel designed for both freight and passenger trains. We analyzed the environmental conditions of the tunnel using temperature and humidity data recorded over approximately one year. The data were recorded using the Tunnel Rough Environment Measuring System (TREMS), which measures environmental data in subway and high-speed train tunnels and is installed in three locations inside the tunnel. Previous studies analyzed environmental conditions inside tunnels located in or near a city, whereas the tunnel in this study is located in a mountainous area. The tunnel conditions were compared with those measured outside the tunnel for each month. Hourly changes during summer and winter periods were also analyzed, and the environmental conditions at different locations inside the tunnel were compared. The results are widely applicable in studies on the thermal environment and air quality of tunnels, as well as for computer analysis of tunnel airflow such as tunnel ventilation and fire simulations.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1138-1143
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• 2004

We as a civil investment enterprise have been constructing In-cheon International Airport Railway which is a transportation means to approach In-cheon International Airport. In this alignment. a section between the Seoul station and Ka-joa follows the existing Yong-san line at the center of Seoul city and traverses Seoul subway 2,5,6 lines. So we planned that the alignment would have the shallowest depth to lie under Kyung-eui line and above the airport railroad. The alignment is planned to construct an open-box structure only 3.6m apart from the subway line 5 tunnel structure and construct the open-box structure 0.7m apart from the subway line 2 box structure. In the line planning, we investigated both the security of the existing subway structures during and after construction and the stability and workability between newly structured tunnel structures with three dimensions numerical analysis methods. Also we raised the reliability of design verification which was achieved by specialty society's review on the planned construction method.

• Journal of the Korean Society for Railway
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• v.15 no.4
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• pp.381-387
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• 2012

This paper is aimed to analyze the achievements of the Tunnel Monitoring System(TMS), implemented in Seoul subway L5~L8, and to find out improved methods. By introducing the TMS, it is possible to inspect tunnel facilities for 24 hours a day while trains are operated. The inspection capability could be expanded, the accuracy was improved, and the cycle was shortened. The efficiency of manpower was improved and the surplus manpower could be used for other tasks of facilities maintenance. As a result, by introduction of the TMS, the amount of tunnel maintenance was increased by 225% and the train service troubles caused by facility problems were decreased by 53%.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.2
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• pp.164-172
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• 2015

Seoul subway plays an important part for the public transportation service in Seoul metropolitan area. As the subway system is typically a closed environment, frequent air pollution problems occurred and passengers get malhealth impact. Especially particulate matters (PM) is well known as one of the major pollutants in subway environments. The purpose of this study was to compare the concentrations of $PM_{10}$ and $PM_{2.5}$ in the Seoul subway system and to provide fundamental data in order to management of subway system. $PM_{10}$ and $PM_{2.5}$ samples were collected in the M station platform and tunnel of Subway Line 4 in Seoul metropolitan and in an outdoor location close to it from Apr. 21, 2010~Oct. 27, 2013. The samples collected on teflon filters using $PM_{10}$ and $PM_{2.5}$ mini-volume portable samplers and PM sequential sampler. The PM contributions were $48.6{\mu}g/m^3$ (outdoor), $84.6{\mu}g/m^3$ (platform) and $204.8{\mu}g/m^3$ (tunnel) for $PM_{10}$, and $34.6{\mu}g/m^3$ (outdoor), $49.7{\mu}g/m^3$ (platform) and $83.1{\mu}g/m^3$ (tunnel) for $PM_{2.5}$. The $PM_{10}$ levels inside stations and outdoors are poorly correlated, indicating that $PM_{10}$ levels in the metro system are mainly influenced by internal sources. In this study, we compared PM concentrations before and after operation of ventilation and Electrostatic Precipitator (EP). Despite the increased PM concentration at outdoor, $PM_{10}$ concentration at platform and tunnel showed the 31.2% and 32.3% reduction efficiency after operation the reduction system. The overall results of this study suggest that the installation and operation of the ventilating system and EP should have served as one of the important components for maintaining the air quality in the subway system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1303-1308
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• 2011

In the modern society various types of transportation mode are utilized, among them the subway system is the one of the main transportation mode which more than 7.21 million people ride a day. Because of interests on the indoor air quality (IAQ) of underground public facilities, concerns on IAQ of subway system by many people are increasing. There are several approach to improve IAQ of subway station, such as installing platform screen door (PSD), frequent tunnel washing-out, and etc, however there has not been any attempt to improve IAQ of subway cabin inside. Most technologies for removing airborne particulate matters are known to be difficult to adopt on the subway cabin since the problem of maintenance cost. Therefore, the ultimate object of this study is a practical development of cabin air cleaning system which can reduce the concentration of airborne particles and harmful gases at the same time. The subway cabin air purifier (SCAP) was developed for removing particulate matters and gases pollutants inside a cabin. The whole system was designed and the roll-filter device was manufactured based on numerical prediction results. It is expected that SCAP could reduce indoor air pollutants in the subway cabin practically and it can be applied to other part of transportation vehicles.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1388-1391
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• 2010

Recently, the construction of road, subway, railroad, and microtunnel for electricity supplement have been increased because of increasement of traffic in urban area, increasement of industrial transportation, and the network between cities in Korea. The deterioration of tunnel structure may occur by various internal and external factors and particularly, tunnel structures tend to contact with either underground water or harmful ions. Therefore, leakage sometimes occurred through the cracks and joints of concrete lining. The leakage in tunnel may affect the durability of concrete lining. In this study, to evaluate the durability and deterioration of concrete lining in tunnel structures, we were performed the various experiments for compressive strength. Compressive strength obtained from nondestructive inspection and compressive strength test varies according to the concrete lining conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.666-674
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• 2010

There is a few problems in the preliminary seismic performance evaluation procedure of subway infrastructures, such as cut-and-cover tunnel structures and bridge structures, recently because the characteristics of subway infrastructures are not properly considered in the procedure. In particular, the evaluation procedure of vehicular bridge structures is applied to subway bridges without any modification. Moreover, the present evaluation procedure is lack of both theoretical and empirical backgrounds, which makes the evaluation less reliable. This paper presents problems in the existing preliminary evaluation procedure and proposes possible modification(revision) to the procedure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.6
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• pp.1083-1090
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• 2009

In 18GHz using unified data transmission in a subway and railway, Influence of the multipath fading is big and an arrival range of the micro wave takes the influence greatly according to the transmit angle and receive angle because it not diffracted. This thesis analyzed microwave property underground tunnel and ground railway at unified data transmission in subway and railway. Antenna gain of directional antenna many used unified transmission in an subway and railway, is used 15dBi and 10dBi in simulation. Transmitter's property is compared underground tunnel to ground railway about curved railway of R=100, R=200, R=400. Specification of transmitter is used sample unified transmission system in subway and railway of KRRI(korea railroad research Institute). Transmitter's power is 20dBm and Reciever's sensitivity is -90dBm. According to result of simulation.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.2
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• pp.216-232
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• 2016

In present, the Seoul City is undergoing traffic congestion problems caused by rapid urbanization and population growth. Thus the City government has reorganized the mass transportation system since 2004 and the subway has become a very important means for public transit. Since the subway system is typically a closed environment, the indoor air quality issues have often raised by the public. Especially since a huge amount of PM (particulate matter) is emitted from ground tunnels passing through the subway train, it is now necessary to assess the characteristics and behaviors of fine PM inside the tunnel. In this study, the concentration patterns of $PM_1$, $PM_{2.5}$, and $PM_{10}$ in the Seoul subway line-2 were analyzed by real-time measurement during winter (Jan 13, 2015) and summer (Aug 7, 2015). The line-2 consisting of 51 stations is the most busy circular line in Seoul having the railway of 60.2 km length. The the one-day average $PM_{10}$ concentrations were $148{\mu}g/m^3$ in winter and $66.3{\mu}g/m^3$ in summer and $PM_{2.5}$ concentrations were $118{\mu}g/m^3$ and $58.5{\mu}g/m^3$, respectively. The $PM_{2.5}/PM_{10}$ ratio in the underground tunnel was lower than the outdoor ratio and also the ratio in summer is higher than in winter. Further the study examined structural types of underground subsections to explain the patterns of elevated PM concentrations in the line-2. The subsections showing high PM concentration have longer track, shorter curvature radius, and farther from the outdoor stations. We also estimated the outdoor PM concentrations near each station by a spatial statistical analysis using the $PM_{10}$ data obtained from the 40 Seoul Monitoring Sites, and further we calculated $PM_{2.5}/PM_{10}$ and $PM_1/PM_{10}$ mass ratios near the outdoor subway stations by using our observed outdoor $PM_1$, $PM_{2.5}$, and $PM_{10}$ data. Finally, we could develop pollution maps for outdoor $PM_1$ and $PM_{2.5}$ near the line-2 by using the kriging method in spatial analysis. This methodology may help to utilize existing $PM_{10}$ database when managing and control fine particle problems in Korea.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1323-1325
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• 2003

In field of Urban transit safely, It must be not only secured vehicle but also every areas like power, signal, communication, track, tunnel, operating facilities. Likewise it is very important not only hardware system like vehicles, facilities but also software system like action of engine driver, duty officer. In other to secure safety of hardware, soft ware, it is very important systemic process. In Korea, Many operating companies neglect to invest in safely and ignore technical development about safety because of management. Safely was considered in subway system and many studies were accomplished about safety in subway system in advanced county like U.K, USA. Hence, in this paper, Conditions and improvement of minimum considerable hardware and software are proposed for safe operation in Urban transit.