• Journal of Environmental Health Sciences
• /
• v.47 no.5
• /
• pp.410-424
• /
• 2021

Background: Subway stations have the characteristics of being located underground and are a representative public-use facility used by an unspecified number of people. As concerns about indoor air quality (IAQ) increase, various management measures are being implemented. However, there are few systematic studies and cases of long-term continuous measurement of underground station air quality. Objectives: The purpose of this study is to analyze changes and factors influencing IAQ in subway stations through real-time continuous long-term measurement using IoT-based IAQ sensing equipment, and to evaluate the IAQ improvement effect of a bio-filter system. Methods: The IAQ of a subway station in Seoul was measured using IoT-based sensing equipment. A bio-filter system was installed after collecting the background concentrations for about five months. Based on the data collected over about 21 months, changes in indoor air quality and influencing factors were analyzed and the reduction effect of the bio-filter system was evaluated. Results: As a result of the analysis, PM₁₀, PM_2.5, and CO₂ increased during rush hour according to the change in the number of passengers, and PM₁₀ and PM_2.5 concentrations were high when a PM warning/watch was issued. There was an effect of improving IAQ with the installation of the bio-filter system. The reduction rate of a new-bio-filter system with improved efficiency was higher than that of the existing bio-filter system. Factors affecting PM_2.5 in the subway station were the outdoor PM_2.5, platform PM_2.5, and the number of passengers. Conclusions: The IAQ in a subway station is affected by passengers, ventilation through the air supply and exhaust, and the spread of particulate matter generated by train operation. Based on these results, it is expected that IAQ can be efficiently improved if a bio-filter system with improved efficiency is developed in consideration of the factors affecting IAQ and proper placement.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.23 no.5
• /
• pp.339-357
• /
• 2021

As the construction of trans infrastructure using the underground tunnel have been rapidly increased, various nearby excavation of existed underground facility including subway structure has been occurred in urban tunnelling. The concern and worry relating to the safety and stability of the existed facility by nearby excavation is becoming the key issues in urban tunnelling. In this study, it was conducted for existed the subway station structure at Seoul subway line which was closely located in the new Dongbuk urban metro railway to determine the behavior characteristics of station structure according to adjacent tunnel construction. Also, it was reviewed the evaluation of the safety zone and excavation method for subway structure. And after a review of damage evaluation, track irregularities and structural calculation by using a numerical analysis, stability of the subway structure according to nearby tunnel excavation was evaluated to be secured. This study is expected to be applied as useful reference in advance if you need to review the effects of existed structure according to nearby construction in complex urban tunnelling.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.1418-1425
• /
• 2011

Subway operators in the country have their own heavy maintenance facilities for maintaining rolling stock(EMU). However, it is true that the heavy maintenance facilities are not utilized 100% with the recent trend of lengthening maintenance cycle(intervals). With the fact, this enabled the existing maintenance facilities to be utilized for other purposes. By taking advantage of spare facilities and the maintenance staff with rolling stock assembly abilities, subway operators can assemble rolling stock by procuring parts for the assembly instead of purchasing trains from other companies. It is estimated that this will enhance the operator's technology and have a great impact on the management skill as well. This study attempts to find out how the heavy maintenance factory can be utilized for rolling stock assembly.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2005.04a
• /
• pp.3-11
• /
• 2005

The structural analysis considering the soil-structure interaction is very important in the design process of underground structures located on the site with various soil conditions. In practice, simplified modelling techniques to obtain the approximate solution are used in accordance with the specifications. However, their details are insufficient for practical engineers to obtain the stable solutions and the analysis results of each engineer occasionally my be different in spite of the same problem. In this study, the sensitivity of structural behaviour on the underground structures is analyzed according to the structural modelling techniques of existing specifications. It is performed to obtain the fundamental informations to establish the guide to obtain the stable solutions in practical analysis of the underground structures such as subway structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.537-542
• /
• 2006

This paper deals with the vibration isolation techniques for a large structure using experimental research. In the case of vibration isolation for the vicinity of a subway or a railroad station, most of vibration isolation techniques using isolation materials with high isolation efficiency only, have been applied. Therefore, the quantitative evaluation and design technologies are required for a vibration isolation of large structures. In this study, firstly, vibration characteristics due to train or subway are analyzed. Secondly, the performance of existing vibration isolation materials such as precision isolation material, elastomer is estimated through the experiments. Thirdly the performance of tire isolation material and its frame is tested and evaluated.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.6
• /
• pp.1286-1292
• /
• 2011

The paper deals with the vibration isolation of a large structure using an experimental technology. In the case of vibration isolation for the vicinity of a subway or a railroad station, most of vibration isolation techniques using isolation materials with high isolation efficiency only, have been applied. Therefore, the quantitative evaluation and design technologies are required for a vibration isolation of large structures. In this study, firstly, vibration characteristics due to train or subway are analyzed. Secondly, the performance of existing vibration isolation materials such as precision isolation material, elastomer is estimated through the experiments. Thirdly, the performance of a tire isolation material and its frame is tested and evaluated. Finally, it is shown that tire isolation materials can be applied to the vibration isolation or vibration reduction of large structures.

• Journal of the Korean Professional Engineers Association
• /
• v.15 no.2
• /
• pp.3-15
• /
• 1982

The study on prevention measures for vibration and excavation of tunnel for the #3, #4, Seoul Subway. In the Seoul subway tunnel blasting, the drilling pattern and prevention method to seismic vibration are as follows as well as for adaptions of NATM, the supportings of roof and wall holes are arranged with control blasting. 1. The blasting is executed basically using the low velocity explosive such as slurry, Nitrate ammonium explosive, and F-I and F-II explosive for control blasting substituting of existing dynamite. 2. The cut holes are arranged with burn cut pattern and also must be arranged with M/S electrical delay caps substituting of ordinary do]ay caps. 3. Jack leg drills are used in Five Job sites and a jumbo drill in one job site. 4. In performance of safety work and in maintenance of building safety. The drilling length for blasting will not exceed 1.20 meter for round so that the vibration value shall carry below 0.3cm/sec. The harmonizing of better powder, better drilling machine and better technique is only the way of improving tunnelling efficiency and less vibration will help the dereasing of accidence.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.6-9
• /
• 2009

The occurrence rate of the earthquake more than magnitude 5 has been increased since 1990 and the damage of the Odaesan earthquake, 2007 was serious. Due to that, one may say that Korea is not any more safe for the earthquake. Therefore, it is necessary to prepare strategies for possible damage due to strong earthquakes in future. This study is to focus to develop the retrofitting system for the cut and cuver tunnels built without earthquake type load scenario, so that it can provide the safety of existing urban subway system against earthquakes.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.957-964
• /
• 2004

The selected structure for the value engineering review is one section of cut and cover tunnel for Seoul Subway Line 9. The primary focus of the review is on the optimisation of the structures to save cost on the existing Line 9 contracts through variation of the design criteria as it affects the permanent works. This is to be achieved through comparison with design criteria for other selected international subways. Criteria resulting from the review must not compromise public safety and durability for the 100 year design life.

• Proceedings of the KSR Conference
• /
• 2008.11b
• /
• pp.645-656
• /
• 2008

The operation of express train on the Seoul Metropolitan Subway Network is centered on the Kyungbu and Kyungin lines and the short section between Dongducheon station and Ganyung station which is 20.7km long. It is true that the needs of many customers who want to reduce their commuting hours by express train is not satisfied. This paper proposes that the operation of express trains be enlarged to Sungbuk station on Kyungwon line which comes to 34.9 km long, and to Yangsu station from Youngsan station on Jungang line. The type of operation is mixed one with high and low speed trains, which operates express train by use of existing siding tracks without improving facilities such as extra building of sidings. This pragmatic study is to apply the goal of reducing running time as express train and to suggest the selection of appropriate stops, effectivenes analysis of express train operation and formation of train diagrams to actual operation.