• Journal of Korean Society of Transportation
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• v.7 no.2
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• pp.53-69
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• 1989

The management of subway business in large cities has recently become more difficult because of increased construction and operation costs. To cope with this situation, it is necessary to examine the methods of obtaining returns on development profits of land value rises that occur due to subway construction along subway lines, For this purpose, we examined the actual situation of rises in land values brought about by the construction of subway line #3 and line #4 in Seoul with application of three methods. In this research, we have calculated a basis of the development profits produced by the construction of subway line. According to the results, development profits produced by the subway construction differ depending on the method adopted. If, however, we accept line comparison analysis method, the total development profits amount to 557,3 billion won that is equivalent to 37 percent construction cost.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.190-205
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• 2012

The purpose of the paper is to provide policy suggestions for effectively tackling subway crimes, based on the UK and USA's crime control strategies and systems of subway crimes. The paper attempts to analyze the characteristics of subway crimes in Seoul Subways, and discovers that many of the crimes on the subways are basically 'opportunistic' crimes. In particular, crime statistics of Seoul Subways clearly show that sexual-related crimes are on the sharp increase. In this context, it is of great essence that official vigilance functions should be strengthened in order to eliminate crime opportunities in Seoul Subways. Based on such an analysis - in particular, focusing on official surveillance and response capabilities of subway passengers - the paper finally presents policy recommendations as follows: 1) an increase in the number of police officers of the Subway Police Squad, 2) an increase in the number of CCTV cameras and their effective use, 3) the development of subway riders' defence abilities, 4) strong law enforcement against minor disorder offences based on zero-tolerance policing, and 5) the reinforcement of community partnerships.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.357-363
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• 2009

In this paper, field measurements in the subway tunnel and adjacent building were performed to predict the pound vibration level induced by urban rapid transit (subway) in Seoul, Korea. From the results of the measurements, the measured ground vibration level induced by subway in Seoul is smaller than the empirical formula of New York, but it is bigger than the empirical formula of Tokyo which has been commonly used in Korea. We suggested the empirical formula for prediction of ground vibration level induced by subway in Seoul considering on the wave propagation path for soils or rocks, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.1
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• pp.59-67
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• 2012

Platform screen doors (PSD) installed at 289 stations in Seoul metropolitan subway from November 2005 to December 2009, are expected to prevent death from a fall and improve air quality. In this study, we systematically surveyed changes in radon concentrations before and after PSD installation in Seoul metropolitan subway stations. By solid-state nuclear track detectors (SSNTD), the radon concentrations before and after the PSD installation were measured at 54 stations of 6 lines from 2 to 7 reported to have relatively high radon concentrations. Mean radon concentrations at platforms were decreased by approximately 56% from 121.7 Bq/$m^3$ to 54.0 Bq/$m^3$. Before PSD installation, mean radon concentrations were in the decreasing order for subway lines 7, 5, 6, 3, 4 and 2. On the other hand, after PSD installation the order was changed to 5, 6, 7, 3, 4 and 2. According to a radon map of Seoul metropolitan subway, the number of platforms where radon concentration over was 74 Bq/$m^3$ decreased from 38 to 12 after PSD installation.

• Journal of the Korean Society for Railway
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• v.19 no.3
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• pp.388-396
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• 2016

The metropolitan subway network of Seoul has gone through many evolutionary processes in past decades to disperse the floating population and improve the traffic flow. In this study, we analyzed how the structural characteristics and the efficiency of the subway network have changed according to the dynamic evolutionary processes of the metropolitan subway network of Seoul. We have also proposed new measures that can be used to characterize the structural properties of the subway network more practically. It is shown that the global efficiency is about 74%, which is higher than those of subway networks of foreign countries. It should also be considered that passenger flow between stations is even higher, at about 85%. Since the private lines, including line 9, the New Bundang line, the Uijeongbu line, and the Ever line do not release their traffic data since September, 2013, only 5 years of data from September, 2008 to September, 2013 is available. So, in this study we limit the analysis period to these 5 years.

• Journal of Soil and Groundwater Environment
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• v.20 no.3
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• pp.41-50
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• 2015

Hydrogeologic environment of the Mega City such as Seoul, suffers from rapid changes caused by urbanization, construction of underground subway or buildings, and contaminant loading by diverse anthropogenic activities. Understanding the present condition of groundwater environment and water budget is necessary to prevent natural and manmade disasters and to prepare for sustainable water resource management of urban environment. In this study, regional groundwater flow and water budget status of Seoul was analyzed using numerical simulation. Modeling result indicated that groundwater level distribution of Seoul generally followed the topography, but the significant decreases in groundwater level were observed around the subway network. Steady-state water balance analysis showed groundwater recharge by rainfall and leakage from the water supply network was about 550,495 m³/day. Surface water inflow and baseflow rate via Han River and major streams accounted for 799,689 m³/day and 1,103,906 m³/day, respectively. Groundwater usage was 60,945 m³/day, and the total groundwater leakage along the subway lines amounted to 114,746 m³/day. Modeling results revealed that the subway could decrease net groundwater baseflow by 40%. Our study result demonstrated that the subway system can have a significant influence on the groundwater environment of Seoul.

• Journal of Environmental Health Sciences
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• v.20 no.1
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• pp.19-27
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• 1994

This paper reports an investigation of concentrations major carcinogenic indoor air pollutants for radon, formaldehyde, and asbestos in the 83 subway stations in the Seoul metropolitan area during November 1991~September 1992. Mean concentrations of indoor pollutants in Seoul subway stations surveyed were 0.23 ppb for formaldehyde, 1.12 pCi/l for radon, and 0.008 fiber/cc for asbestos. Mean formaldehyde concentrations in 83 subway stations were below the U.S. EPA formaldehyde standard (100 ppb), whereas mean concentrations of radon and asbestos in 2% and 22% of total sampled subway stations exceeded the U.S. radon (4 pCi/l) and asbestos (0.01 fiber/cc) standand, respectively. It is likely that possible sources for radon and asbestos are radon intrusion from the leaking underground water and construction materials, respectively.

• Journal of Information Technology Services
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• v.19 no.2
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• pp.125-138
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• 2020

Currently, subway crowding is estimated by observing a specific point at specific hours once or twice every 1 or 2 years. Given the extensive subway network in Seoul Metropolitan Area covering 588 stations, 11 lines and 80 transfer stations as of 2017, implementing crowding mitigation policy may have its limitations due to data uncertainty. A proposal has recently been made to effectively use smart card data, which generates big data on the overall subway traffic related to an estimated 8 million passengers per day. To mitigate subway crowding, this study proposes two viable options based on data related to smart card used in Seoul Metropolitan Area. One is to create a subway passenger pattern model to accurately estimate subway crowding, while the other is to prove effectiveness of early bird policy to distribute subway demand that is concentrated at certain stations and certain time. A subway passenger pattern model was created to estimate the passenger routes based on subway terminal ID at the entrance and exit and data by hours. To that end, we propose assigning passengers at the routes similar to the shortest routes based on an assumption that passengers choose the fastest routes. In the model, passenger flow is simulated every minute, and subway crowding level by station and line at every hour is analyzed while station usage pattern is identified by depending on passenger paths. For early bird policy, highly crowded stations will be categorized based on congestion level extracted from subway passenger pattern model and viability of a policy which transfers certain traveling demands to early commuting hours in those stations will be reviewed. In particular, review will be conducted on the impact of policy implemented at certain stations on other stations and lines from subway network as a whole. Lastly, we proposed that smart card based subway passenger pattern model established through this study used in decision making process to ensure effective implementation of public transport policy.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.1
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• pp.17-31
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• 2004

The subway play an important part in serious traffic problems. However, because subway system is a closed environment, many serious air pollution problems occurred in subway stations and injured passenger's health. Therefor, it is a necessary to identify sources and to estimate pollutant sources in order to protect passenger's health and to keep clean subway environment. The purpose of this study was to analyze a air quality in the subway stations and to apply a new receptor methodology for quantitatively estimate of PM10 sources. In this study, the size distributions of particulate matters has been measured by using Aerosizer LD (U.S.A., API, Inc.). It's real time measurement capability of time-of-flight technique offers a significant advantage of user convenience and air pollution management. Also, the mass concentrations of PM 10 has been measured by using mini-vol portable sampler (U.S.A., Airmetrics Co.). The sampling performed in Seoul subway stations during the period of February 2000 and April 2000. The number distribution data used in this study consisted of 26 raw data sets in the Jongno-sam-ga station. Correlation Analysis can be used in subway stations for source separation and identification. Then, number contribution from each source is determined by the particle number balance (PNB). The mass concentration data used in this study consisted of 31 raw data in the 8 different stations. The mass contributions of PM10 sources in the concourse by using PMF/CMB model.

• Proceedings of the Korean Geotechical Society Conference
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• 1993.10b
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• pp.51-76
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• 1993

More than sixty percentages of tunnels in the second phase of Seoul subway project have the ground coverages less than twenty meters. Majority of ground conditions encountered during turutel ling, therefore, are weathered rocks or weathered scils. Substantial lengths of tunnels are being constructed and designed running through the alluvial deposits as well. A comprehensive evaluation of current design and construction technology of Seoul subway tunnels is made with four categories such as site investigations, design concepts and methods, auxiliary measures and quality controls. Critical comments are given and some suggestions for the improvement of technology are presented.