• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1533-1539
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• 2007

It is mainly due to the toxic gases, produced from the material combustion, threatens human body in case of urban railway car like subway which passes through underground tunnel. In the field of railway industry, fire accidents was not frequent but occurs in each country and, the causes was investigated. The advanced country established the test standard (e.g., BS, EN) to measure the toxic gases quantitatively and, have applied to enhance the fire safety of railway car. We must also follow the procedures to use gangway material for railway car as stated the Safety regulation for the urban railway car. In this study, various gangway materials(silicon, synthtic rubber, soaltapulin) are used to investigate element of toxic gases when the fire occurs. The amount of toxic gases measured from the ISO 5659 chamber using cone heater was measured and compared the results for each materials.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.559-563
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• 2024

Currently, in Korea, large-scale, deep excavations are being carried out adjacent to structures due to overcrowding in urban areas. for adjacent excavations in urban areas, it is very important to ensure the safety of earth retaining structures and underground structures. accordingly, an automated measurement system is being introduced to manage the safety of subway tunnel structures. however, the utilization of automated measurement system results is very low. existing evaluation techniques rely only on the maximum value of measured data, which can overestimate abnormal behavior. accordingly, in this study, a vast amount of automated measurement data was analyzed using the Gaussian probability density function, a technique that can quantitatively evaluate. highly reliable results were derived by applying probabilistic statistical analysis methods to a vast amount of data. therefore, in this study, the safety evaluation of subway tunnel structures due to adjacent excavation work was performed using a technique that can process a large amount of data.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.131-144
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• 2018

The urban center of a large city has a high concentration ratio of population, commerce, and traffic. Therefore, the expected effect is high from the introduction of the urban utility tunnel and it also has sufficient economic feasibility considering life cycle cost. Moreover, the construction cost can be greatly reduced if it is included in a large underground development such as a subway or a complex transfer center construction. However, it is not reflected in actual underground development plan. When planning a urban utility tunnel in Korea, it is expected to have difficulties such as the cost of relocation of the existing Life-Line, conflicts among the individual facility institutions, procurement of construction resources and sharing. Furthermore, it is possible to promote the project only if a consensus is drawn up by a collective council composed of all facilities and project developers. Therefore, an optimal alternative should be proposed using economic analysis and feasibility assessment system. In this study, the analytic hierarchy process (AHP) is performed considering the characteristics of urban areas and the importance of each indicator is quantified. As a result, we can support reasonable design capacity optimization using the feasibility assessment system.

• Journal of Korea Water Resources Association
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• v.40 no.4
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• pp.313-324
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• 2007

An irregular cell-based numerical model was developed to analyze underground space flooding. In this model, the flow characteristics in underground space were computed by link-node system. Also, the model can simulate the underground flood flow related to the influence of stairs and wall-structures. Empirical discharge formula were introduced to analyze weir-type flow for shopping mall, and channel-type flow for subway railroad respectively. The simulated results matched in reasonable range compared with the observed depth. The dual-drainage inundation analysis model and the underground space flood analysis model were integrated using visual basic application of ArcGIS system. The developed model can help the decision support system of flood control authority for redesigning and constructing flood prevention structures and making the potential inundation zone, and establishing flood-mitigation measures.

• Fire Science and Engineering
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• v.25 no.1
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• pp.72-77
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• 2011

The effort of transferring some parts of urban functions to the underground space is growing trend among modem cities because of the limit of horizontal land use, the rise of land value, the diversification of human desire, etc. Thus, the basement of building and the subway station have deepened. It calls our attention to safety about evacuation from the underground space to the ground. Until now, the study about crowding walk in stairs has been progressed, focusing on the crowding walk that is going down the stairs, and there is no study about crowding walk that is going up the stairs. This study measured walking pace by crowd density that is going up the stairs in the subway station stairs making one-way movement of crowd. The actual survey showed that the mathematical relation 'V=0.638-0.0949p' determines going up walking velocity at a gradient of $23^{\circ}$, and the mathematical relation will be 'V=0.597-0.1067p' at a gradient of $30^{\circ}$, when it is converted, based on the average walking velocity of crowd by the slope of the stairs which is recommended by Architectural Institute of Japan.

• Journal of Environmental Science International
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• v.20 no.12
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• pp.1553-1560
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• 2011

The study analyzes groundwater balance with regard to the water recharge and discharge which contain urbanization components in Suyeong-gu, Busan. It also verifies the reliability and accuracy improvement on the analysis of the balance. The result of the study is viewed as preliminary data which are useful to develop, utilize and manage groundwater. The average quantity of groundwater recharge is 6,014.1 $m^3$/day in the research area during the last ten year period(from 1998 to 2007). The outflow from drainage areas to rivers and coasts is 149.3 $m^3$/day, the inflow from rivers and coasts to drainage area is 439.9 $m^3$/day. The use of the water is 4,243.0 $m^3$/day. The outflow caused by subway in line No.2 and No.3 through Suyeong-gu and the one by building an underground electric complex is 1,500.0 $m^3$/day. The leakage of water works is 6514.9 $m^3$/day. The inflow and outflow of sewerage is 5082.2 $m^3$/day from groundwater to sewer. The amount of groundwater recharge, the inflow from rivers and coasts to drainage area, and the leakage of water works belong to the amount of groundwater inflow and the total amount is 12,968.9 $m^3$/day. The amount of outflow from drainage area to rivers and coasts, the use of groundwater, outflow by subway and underground electric complex tunnel and the amount of inflow of the water to sewerage belong to the amount of outflow of groundwater and the sum amount is 13,031.5 $m^3$/day. The gap between the amount of inflow and outflow of groundwater is 62.6 $m^3$/day, which is considered to reflect the trend that the short term drop in the amount of rainfall results in the amount of groundwater recharge and that the amount of outflow from drainage area to rivers and coasts decreases.

• Journal of the Korean Society for Railway
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• v.19 no.3
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• pp.380-387
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• 2016

Considering that the Seoul subway sector is expected to see extension of lines, addition of stations, and changes of operating companies, a review is needed to identify ways to eliminate or minimize financial deficits in its operation. As for deficits from the operation, additional businesses for extra income have been suggested as alternatives, but inasmuch as Western urban development (that of the subway containment area) may not be applicable to Korean settings, a practical alternative is to maximize income by efficient use of rental facilities that are located inside station properties. This alternative requires the estimation of appropriate facility size and rent for each station; few, however, have addressed this topic. At this juncture, this study aimed to draw an equation for estimating the sizes and rents of station properties by reflecting characteristics of lines and locations; a case study was performed for Subway Lines 5 and 6. Analytical findings are that rental facility sizes and rental incomes are affected mainly by the subway ridership and transport revenues, whereas the influence of ground-level commercial activity is relatively weak. A particularly great influence was found to be the value of apartment housing in areas through which the subway lines run. Stations on Line 5, which runs through areas of high-value housing, were assigned smaller facility sizes and higher rents than those on Line 6, which covers areas with relatively low housing value. The equation suggested in this study would make possible more practical feasibility studies when the need arises to estimate sales of new or extended facilities affiliated with stations.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.5
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• pp.281-302
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• 2021

Railway projects have been consistently increasing in Korea. In relation to this trend, the mechanized tunneling using Tunnel Boring Machine (TBM) is preferably applied for mining urban areas and passing under rivers. The TBM tunneling under difficult grounds like mixed faces with high water pressure could require ground improvements for stable TBM advance or safe cutter head intervention (CHI). In this study, pre-grouting works for CHI in Daegok-Sosa railway project are presented in terms of the grouting zone design, the executions and the results, the lessons learned from the experience. It should be mentioned that the grouting from inside TBM was carried out several times and turned out to be inefficient in the project. Therefore, grouting experiences from the surface are highlighted in this study. Jet grouting was implemented on CHI points on land, while permeation grouting off shore in the Han River, which mostly allow to access the cutter head of TBM in free air with stable faces. The results of CHI works have been analyzed and the lesson learned are suggested.

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.6
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• pp.443-450
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• 2010

A concrete lining of NATM tunnel had been considered as interior materials. But recently we consider it as structural materials. Therefore we must consider various loads. Relaxed rock load is a main load which decides thickness and reinforcement presence of concrete lining. In practice conservatively, Terzaghi's rock load theory has been accepted to estimate relaxed rock loads in urban subway tunnel design. This study investigates the equations of relaxed rock loads used in the design of NATM concrete lining. Structural analysis are executed based on various equations of relaxed rock loads, and concrete lining forces are compared.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.202-210
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• 2018

Recently, the subway running in metro environments has a problem in securing the safety of passengers due to the failure of announcement in emergency situations such as breakdown, train accidents and power outage in the underground tunnels. Thus, there is a need to develop an emergency broadcasting system that can provide the announcement to all passenger cars in any emergency situations on the railway route. In this paper, the applicability of various wireless communication technologies for the emergency broadcasting system through the measurement campaign was examined in Seoul metropolitan subway. A WAVE(Wireless Access in Vehicular Environments) is communication technology that can use 5.9GHz dedicated frequency band without charge and it is possible to directly communicate between terminals over 200m without the help of additional relay. Especially, it confirms robust communication performance in the various metro environments, and therefore, it is considered to be suitable as a communication method of a radio-connected emergency broadcasting system for urban subway.