• The Journal of Engineering Geology
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• v.33 no.4
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• pp.689-699
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• 2023

Assessing ground stability is critical to the construction of underground transportation infrastructure. Surface displacement is a key indicator of ground stability, and can be measured using interferometric synthetic aperture radar (InSAR). This study measured time-series surface displacement using permanent scatterer InSAR applied to Sentinel-1 SAR images acquired from January 2017 to June 2023 for the area around a deep underground expressway under construction to connect Mandeok-dong and Centum City in Busan, South Korea. Regions of seasonal subsidence and uplift were identified, as were regions with severe subsidence after summer 2022. To evaluate stability of the ground in the construction area, the mean displacement velocity, final surface displacement, cumulative surface displacement, and difference between minimum and maximum surface displacement were analyzed. Considering the time-series surface displacement characteristics of the study area, the difference between minimum and maximum surface displacement since June 2022 was found to be the most suitable parameter for evaluating ground stability. The results identified highly unstable ground in the construction area as being to the north of the mid-lower reaches of the Oncheon-cheon River and to the west of the Suyeong River at the point where both rivers meet, with the difference between minimum and maximum surface displacement of 40~60 mm.

• Tunnel and Underground Space
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• v.8 no.1
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• pp.17-25
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• 1998

This paper investigates coupled thermal, mechanical and hydraulic phenomena in deep rock mass especially for underground heat storage system. Firstly, concepts of underground heat storage were presented and coupling phenomena in this area were illustrated. In order to understand the basic mechanism of thermal, hydraulic and deformation behavior in rock cavern disturbed by thermal gradient about 10$0^{\circ}C$, various numerical experiments were conducted using several codes. The study involves the behavior of fractured rock mass including rock joint. In spite of the limitation of codes modelling fully coupled effects, these codes could be applied in analysis of underground heat storage. The heat loss in rock mass, which is a major factor in heat storage, is insignificant in all results.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.82-87
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• 2005

The characteristics of train-wind in the underground shopping center(UGSC) connected to subway station is investigated by field measurement for the case of train movement such as arrival and departure, etc. Also air curtain installed at the pass way between underground shopping center and subway station were considered as the parameter in order to analysis the effect on indoor air quality and thermal condition. The measurement data such as velocity, relative humidity, wind-pressure were plotted as quantity variation with time scale. The train-wind affected wind velocity, air pressure and relative humidity at the connecting area of underground shopping center and subway station, and the variation was about 4.5 m/s, 8%, 40 Pa. Also the result showed that the air curtain is not proper to reduce influence of train-wind

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.3
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• pp.124-135
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• 2000

This paper presents reasonable evaluation technique to determine system configuration of underground distribution system. To set up reasonable evaluation for a certain object region, it is necessary for methodology to access accurately factors such as economics, reliability, customer interruption cost, implementation and flexibility about proposed various configuration of underground distribution system. But it is difficult to evaluate factors as above-mentioned since there is no criterion to assess them in our country. Accordingly, having completed the technical and economical analysis and customer interruption cost of various types of system, this paper presents the most reasonable results to get the optimal configuration of underground distribution system. Also, this paper presents possible methodology which can be applied other areas having a different load characteristics by application actually making a selection Myungdong as sample area.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.4
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• pp.193-200
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• 2003

The use of underground transmission tables has continuously increased in densely inhabited urban and suburban area. Due to a increasing demand of underground cables, two or more circuits are installed in parallel for several kilometers. It, however, has not been realized that the sheath circulating current is generated in the system where a large number of cables are laid in the same route. In this paper, Author studied diversely the sheath circulating current on underground cables depending on the various length rate, the phase arrangement, and the grounding resistance of the sheath in the cross-bonded section. It was clear that very large circulating current is generated in cable systems due to unbalanced length rate and phase arrangement in the cross-bonded section.

• Journal of Korea Society of Industrial Information Systems
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• v.18 no.3
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• pp.9-15
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• 2013

This paper was development of remote controller of pumping system by using ubiquitous for underground water contamination prevention in the area of glasshouse facility. This paper automatically controls from to temperature and humidity for pumping sprinkler at water hanging cultivation. This prevents indiscreetive development of underground water, and prevents damage of environmental pollution without complementary measures in case of water lacked humble-void. The result of this research, confirms decrease of electrical fee, prevention of indiscreet underground water usage and its drying up thought optimum farm products management and pumping control system.

• Geomechanics and Engineering
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• v.17 no.6
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• pp.573-581
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• 2019

Excavation of underground cavern and shaft was proposed for the construction of a ventilation facility in an urban area. A shaft connects the street-level air plenum to an underground cavern, which extends down approximately 46 m below the street surface. At the project site, the rock mass was relatively strong and well-defined joint sets were present. A kinematic block stability analysis was first performed to estimate the required reinforcement system. Then a 3-D discontinuum numerical analysis was conducted to evaluate the capacity of the initial support and the overall stability of the required excavation, followed by a 3-D continuum numerical analysis to complement the calculated result. This paper illustrates the application of detailed numerical analyses to the design of the required initial support system for the stability of underground hard rock mining at a relatively shallow depth.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.445-456
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• 2010

Massive underground excavation can be carried out recently due to the technical development of the excavation for retaining wall. Feed-back analysis using field measurement results is recommended to secure the stability of the construction because calculated values at stages of the design and the construction are uncertain. Reinforcement plan should be established based on the result of it. This study deals with the underground excavation site, which is under construction and is close to structure(subway) at downtown area. The result of feed-back analysis on the measurement data of displacement at multi-soil layers was reflected to make a plan for safe construction. This case study can be useful information for contingency plan on abnormal displacement which can be occurred at similar underground excavation.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.949-952
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• 2010

The utilization of LPG(Liquefied Petroleum Gas) is increasing as an environmental-friendly fuel in all countries making green growth new paradigm, and use of gas is spread fast as motor fuels to decrease air pollution. Loss of lives by explosion and fire is happening every year as gas use increases, and gas accident in large scale storage property is causing serious problems socially. To minimize this problem, underground containment type storage tank is being presented as an alternative recently. In this study, to minimize explosion occurrence in underground containment type storage tank, the suitable storage tank is designed to consider explosion prevention that makes exposure surface area minimize in confined contents volume and flame to construct storage tank by the most suitable condition in the underground containment room. As a result of the design of storage tank having the most suitable condition by this research, underground containment space was minimized on diameter 3m, length 4.83m in 20 tons storage tank and its safety was improved as exposure surface area in flame decreased by 89.4%, compared with the existent storage tank.

• Journal of the Korean Society of Systems Engineering
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• v.17 no.2
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• pp.122-128
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• 2021

Despite various economic crises, the domestic parcel delivery market handled 3.37 billion parcels in 2020 while maintaining annual growth due to the activation of e-commerce. In particular, in the case of the metropolitan area, which accounts for about 70% of the nation's parcel throughput, the increase in parcel delivery volume is directly related to the increase in freight vehicles in central area of Seoul,. And it leads to an increase of unnecessary social and environmental costs such as traffic congestion, road damage, and environmental pollution in the city. Therefore, in this paper we proposed the underground urban logistics system utilizing the existing urban rail infrastructure, and establish a conceptual design by operational scenario. In order to establish conceptual design of underground urban logistics system, we use order picking system process, which is use in warehouse, produce result combined ISO/IEC 26702. The results of this study can be usefully used before the underground urban logistics system is introduced.