• Proceedings of the Korean Geotechical Society Conference
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• 1993.10b
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• pp.3-30
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• 1993

To ease traffic congestion Seoul Metropolitan Government formulated the 2nd Phase of Seoul Subway Construction Scheme in 1989. The scheme calls for the construction of %60 km of subway which includes addition of 4 more subway lines and extension of 3 existing subway lines in addition to the existing 118 km of subway. As a final stage of the scheme subway line 6 is under planning and design. The line 6 is 36.1 km-long route connecting Ungam-Samgakchi-Changsin-Sinnae. Except for the depot main line wilts be underground and major construction methods are cut and cover and tunnelling. As a tunnelling method New Austrian Tunnelling Method will be adapted. The line will be opened by the end of 1997. With the completion of the line Seoul will have 278 km of subway network and the transport share by subway will be increased from 25% in 1992 to 50% in 1997.

• Proceedings of the KOR-KST Conference
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• 1998.09a
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• pp.3-16
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• 1998

The goal of the transportation policy of Seoul is to increase the ridership of the subway system by constructing the public transportation network, the subway system. To accomplish this goal, the city of Seoul has been constructing the Metropolitan Subway System. Currently, seven subway lines which connect major areas in Seoul are operating. However, the ridership of subway system was not increased as much as we expected, even though more subway lines have been implemented. It seems that although the length of the subway line was extended, the current way of the subway operation that trains stop at every station cannot satisfy the passenger's need. Thus, we should try to increase the demand by providing quicker services and diversifying the subway operations; changing the point of view is required. This paper introduces the distinctive features of the express subway system and the model for analysing the effects of that system. This paper also presents the results for the feasibility study of the express subway system on the 5th Subway Line and Kyong-Eue Railway Line. Based on the results of the case studies, We can conclude as : First, the express system reduces a total travel time by about $13\%$; in particular, the Kyong-Eue Line is more effective than the subway Line ${\sharp}5$. Second, the shorter headway of express trains increases the time saving effects on subway system although it requests more waiting time to low-speed train passengers. When the service frequency is increased from 5 to 7.5 times/hour, total saved time ratio is about $10\%$ in the Subway Line ${\sharp}5$ and about $18\%$ in the Kyong-Eue Line.

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.6
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• pp.593-604
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• 2017

The suspended particulate matter(PM) was measured in subway tunnel of Seoul Line 1 to 9 in order to evaluate the pollution degree and characteristics of the PM in the subway tunnel. Also, to analyze the effect of outdoor aerosol concentration on the PM concentration of subway tunnels, the ambient PM concentration around the subway station was extracted by spatial analysis using $PM_{10}$ data of Seoul air pollution monitoring network. Finally, in order to understand pollution pattern in the Seoul subway tunnels, cluster analysis was performed based on input data set such as PM levels in tunnel, tunnel depth, length, curvature radius, outdoor ambient air pollution levels and so on. The average concentration of $PM_{10}$, $PM_{2.5}$, and $PM_1$ on subway tunnels were $98.0{\pm}37.4$, $78.4{\pm}28.7$, and $56.9{\pm}19.2{\mu}g/m^3$, respectively. As a result of the cluster analysis, tunnels from Seoul subway Line-1 to Line-9 were classified into five classes, and the concentrations and physical properties of the tunnels were compared. This study can provide a method to reduce PM concentration in tunnel for each pollution pattern and provide basic information about air quality control in Seoul subway tunnel.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.374-383
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• 2012

In this study, we have observed the airborne radon levels in the subway cabins before and after platform screen doors (PSD) installation. The measurements have been conducted at Seoul metropolitan subway lines in 2008, 2009 and 2010. The mean concentration of the radon inside subway cabins were increased by approximately 53% from $20.1Bq/m^3$ to $30.8Bq/m^3$ by installing PSD. After PSD installation, measured values for the different lines were rather different, and varied between 8.2 and $76.5Bq/m^3$. And mean radon concentrations were in the decreasing order for subway lines 5, 6, 7, 8, 3, 4, 2, 9 and 1. It was also found that the indoor radon concentrations in the subway cabins were highly dependent on the management approach of a ventilation system at the subway stations. By assuming an average of $720\;h\;year^{-1}$ and $2,880\;h\;year^{-1}$ spent in subway cabin, effective doses to passengers and employee were estimated. The expected annual effective dose, in case of an equilibrium factor of 0.4, were $0.07mSv\;y^{-1}$ and $0.26mSv\;y^{-1}$, respectively.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.354-356
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• 2009

Air quality analysis is done for subway trains and subway platforms of subway line number 2 using mobile environmental sensor modules. $CO_2$ and PM10/PM2.5 particulate concentration are investigated for screen door systems, under-ground platforms, and transfer stations. These results would help to increase the quality of life of subway railroad passengers.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.2
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• pp.175-187
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• 2014

The subways play an important part in serious traffic problems. Almost seven million citizens a day are using subways as a means of traffic communication in the Seoul metropolitan city in 2012. However, the subway system is a semi-closed environment, so many serious problems occurred in subway stations and injured passengers' health. Platform screen doors (PSD) are expected to prevent negligent accident such as injury or death from falling and improve the air quality of the subway station. Installation of PSD at stations in Seoul metropolitan subway had been completed in December 2009. Consequently, the underground transportation system became a closed environment, so the air quality has improved the platforms, but it has deteriorated in the tunnels. Especially, the subway cabin has many doors, and the doors are frequently opened and closed. For this reason, the effect of door opening on subway cabin, dust flow inside the subway cabin. In this process, the maintenance work may influence the health of people who work underground, as well as that of subway users (passengers). In this study, we measured air quality inside and outside of the subway cabin line 2 in Seoul, Korea. This study focused on the investigation of Indoor Air Quality (IAQ) and measurement target pollutants are PM10, CO, $CO_2$, $NO_2$, $O_3$. It was found that levels of PM10, $CO_2$, and $NO_2$ inside subway cabin line 2 exceeded the Korea IAQ standard. Concentrations of PM10, $CO_2$, and $NO_2$ inside of the cabin are higher than outside of the cabin (Indoor Outdoor ratio is higher than 1.). Concentrations of CO, $O_3$ inside of the cabin are lower than outside of the cabin (Indoor Outdoor ratio is lower than 1.). There is a high correlation between $CO_2$ and passengers inside of the cabin and PM10 is only the weakest correlation with passengers. Therefore, it is important to find out the emission source of $NO_2$. The results of this study will be useful as fundamental data to study indoor air quality of a subway cabin.

• International Journal of Railway
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• v.9 no.1
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• pp.21-26
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• 2016

When excavation under existing structure is planned for a new construction project, the underpinning method is one of the most applicable construction methods. This study introduces a new modified underpinning method which is applied to construct a new subway line in Seoul Metropolitan. The new subway line was designed to pass underneath the existing subway line. Existing subway line carries about 2 million passengers daily, which is 33% of total passengers using subway in Seoul, and is the only circulation line in Seoul. Subway trains are passing 540 times through this section in a day. By applying a new underpinning method, the subway box structure of line is exposed 54m in the air supported by bearing piles. The proposed method was carefully monitored using heavy instrumentation system during construction. This study proposed and verified the application of the modified underpinning method, which can reduce construction period by 1.5 times and the construction cost by 1.2 times comparing with conventional method. The importance of considering construction sequence is investigated and verified by analyzed data non-considering construction sequence. The unexpected heaving which can bring up a dangerous situation for train running stability were measured, so this study shows that the upward movement has to be analyzed in designing process. As the use of underground space increases, the proposed method can be a good example of underground development.

• KIEAE Journal
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• v.15 no.4
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• pp.53-60
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• 2015

Purpose: Subway in Seoul, Korea is an important urban mass transportation system as it carries more than 4 million people a day. To support this important mission, subway entrances were designed and installed to maximize accessibility to the stations. However, a uniform plan by the national government guided quantity and layout of the subway entrances. Therefore, the plan did not consider unique characteristics of each station area and reorganization of the subway entrance system is required to improve pedestrian environment. Method: This study grouped the subway entrances into specific patterns to propose reorganizing schemes. The authors conducted field surveys, examined case studies and proposed an entrance reorganizing plan for each type. Result: The study recommends subway entrances be installed inside adjacent building when large commercial or office complexes are nearby. The authors proposed installing a bridge connecting the stations and adjacent buildings for elevated entrances. This would be only possible when there are commercial or office facilities nearby with enough floor space. The study summarizes the pros and cons of each solution. To translate our proposals into realities, various incentives should be given to building or land owners. This study made suggestions as to which kinds of incentives exist and be effective in a range of situations.

• Journal of Environmental Health Sciences
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• v.35 no.6
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• pp.454-460
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• 2009

The subway is the major public transportation system in Seoul with 2.2 million people using it everyday. Indoor air pollution in the subway can be a significant part of population exposure because of the number of people using the subway, time spent in transit and potentially high exposure for certain pollutants. The Korea Ministry of Environment has established the level 2 of recommended standards of $PM_{10}$ and $CO_2$ in subway trains. The aims of this study were to determine the airborne levels of $PM_{10}$, $CO_2$ and any correlation between pollutant levels and number of passenger in a subway train. The airborne $PM_{10}$ and $CO_2$ were measured on the inside of trains on line #4 for 4 different days from October to November in 2008. Average $PM_{10}$ and $CO_2$ levels were $113{\pm}25{\mu}g/m^3$ and $1402{\pm}442$ ppm, respectively. These levels did not exceed the level 2 of recommended standards of $250{\mu}g/m^3$ for $PM_{10}$ and 3500 ppm for $CO_2$. $PM_{10}$ level was not correlated with the number of passengers, while $CO_2$ levels were positively correlated with the number of passengers. The findings suggested that $PM_{10}$ in subway trains may have sources other than those directly associated with the number of passengers.

• Journal of Digital Convergence
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• v.18 no.10
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• pp.437-442
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• 2020

Information boards installed in Seoul subway stations are currently in four languages: Korean, English, Chinese, and Japanese. Informational announcements are provided to inform the main information or operation information through the LCD monitor installed in the train and in Korean. However, users are confused because the subway guide board screen displays advertisements more heavily than driving information As a research method, we grasped the current status and problems of the subway guide board installed on the Seoul subway, and presented an improved new subway guide board drafts. An online survey was conducted on 67 people, ranging from teens to 60s who mainly use the Seoul Metro. As a result of the study, the screen design is different for each boarding route, so it is necessary to unify the subway guide board that provides only necessary information. In particular, since the user transfers the subway several times in order to move from place to place, the subway guide board design should function as an emergency disaster guide or boarding information, not an advertising signboard.