• Proceedings of the KSR Conference
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• 2007.11a
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• pp.595-600
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• 2007

Greater expansion and more frequent operation of the railroad transportation system anticipated due to its characteristics including low cost, safety and mass transportation. Recently, effects on the railway structures due to expansion of newly constructed road, construction of subway, city gas pipeline, communication network, electric power network and construction of other railway underground crossing in accordance with urban planning and organization has influenced safe operation of trains. Accordingly, standard for selection of construction method that will enable construction of more economical and rational subway underground crossing structures by preventing problems occurring at the time of above construction works and accidents in safe operation of trains due to construction in advance is definitively necessary. Although there are numerous construction methods that can be applied at the time of construction of railway underground crossing, there are much difficulties in selection of appropriate construction method that considers characteristics of each construction method on non-excavation type construction method, train operation plan of number of operational routes and on-site circumstances. Therefore, this research aims to present rational standard for selection of construction method for such, and standard for slowdown speed and interception of train when passing the areas of slowdown in sectors under construction.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1039-1046
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• 2018

This paper presents a limit analysis of the series of construction stages of shallow tunneling method by investigating their respective safety factors and failure mechanisms. A case study for one particular cross-section of Beijing Subway Line 7 is undertaken, with a focus on the effects of multiple soil layers and construction sequencing of dual tunnels. Results show that using the step-excavation technique can render a higher safety factor for the excavation of a tunnel compared to the entire cross-section being excavated all at once. The failure mechanisms for each different construction stage are discussed and corresponding key locations are suggested to monitor the safety during tunneling. Simultaneous excavation of dual tunnels in the same cross-section should be expressly avoided considering their potential negative interactions. The normal and shear forces as well as bending moment of the primary lining and locking anchor pipe are found to reach their maximum value at Stage 6, before closure of the primary lining. Designing these struts should consider the effects of different construction stages of shallow tunneling method.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.214-220
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• 2011

As the number of subway user increases, not only interests in safety increase but also interests in evacuation for a conflagration expand after 'Daegu Subway Fire Disaster' took place. It is necessary to revise the standard of evacuation time and guidelines to guarantee safety of station and platform considering changes in subway environments caused by construction of the deeply underground subway station. Hence this study investigates the current status of the evacuation time of respective station through a site investigation and the results of this study may be utilized as a basic material to calculate an appropriate evacuation time.

• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.2
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• pp.103-111
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• 2006

To optimize the ventilation and smoke control systems in subway equipped with platform screen door, the technology to analyze the unsteady tunnel flow caused by running of train should be developed. The development of model experiment and numerical analysis technique with relation to unsteady flow of subway were presented. The pressure and air velocity changes in 1/20-scaling experiment unit were measured and results were comparied to those of 3-D unsteady numerical analysis applied with sharp interface method. The experimental and numerical results were quantitatively similar and it would be reasonable to apply sharp interface method to analyze the unsteady flow in subway equipped with platform screen door.

• Proceedings of the Korean Geotechical Society Conference
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• 1990.10a
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• pp.69-86
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• 1990

This paper discusses how to protect the principal structures adjacent to subway tunnels being constructed by the shield or cut-and-cover methods by referring to some actual examples.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.107-110
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• 2007

There it has been progressed study about the city of land use and change detection in different period. The aim of the study is to find the differences in spatial change for subway construction lines using Landsat TM and SPOT image. The result of study to use judge the data in subway role about the city growth. In the recently, it will be expected to use important basis data in development of the city.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.1
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• pp.59-64
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• 2011

Feasibility study on energy saving system by utilizing exhausted heat from subway, which is one of the unused energy, was carried out. General heat source system using absorption chiller-heater was used for comparing to the energy saving system, and payback period method using initial cost and running cost of two systems, was used to perform economic estimation. Payback period was about ten years, and this period might be shortened if nation's economic support enact.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.700-709
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• 2009

FBG sensor system is applied to the concrete lining structure in Taegu subway. Near the structure, the power cable tunnel construction started. We wanted to measure the deformation of the structure due to the construction by the FBG sensor. The applied sensor has the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well.

• Tunnel and Underground Space
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• v.34 no.3
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• pp.196-207
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• 2024

In this study, a comprehensive management plan was proposed to ensure the stability of the existing subway when constructing ground structures adjacent to the subway. In the first step, the measurement inspection cycle is selected through proximity evaluation, in the second step, the stability of existing subway and station structures such as displacement and stress is reviewed through 3D numerical analysis considering the construction stage and groundwater influence, and in the third stage, the safety of train operation was reviewed by examining the track stability, and based on the numerical analysis results in the fourth stage, the displacement concentration section was selected as an intensive management section and it was proposed that intensive measurement management be performed.