• Magazine of korean Tunnelling and Underground Space Association
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• v.1 no.2
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• pp.59-71
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• 1999

Recently, many deformations in tunnel such as crack and leakage were occulted. Specially, the defects of tunnel lining have been a serious problem in safety and stability many repair works for maintenance in tunnel have been carried out. Therefore, it is necessary to estimate the structural cracking for countermeasure in deformed tunnel and to investigate on the characteristics of lining system and the soundness of tunnel. In this study model tests for tunnel lining were carried out using test apparatus and centrifuge, In the direct loading test, the prototype was Kyungbu high-speed railway tunnel and the scale is 1/10, and lining models were made of concrete. Test conditions included load conditions such as direction, shape and type, lining conditions such as single and double lining, thickness, and reinforcement. In centrifuge model test, the prototype was Seoul subway tunnel and the scale is 1/100, and lining models were made of aluminum and hydrostone. Test conditions included tunnel defects such as thickness shortage. behind cavity and longitudinal cracks, reinforcement methods such as epoxy, grouting and carbon sheet. From these model tests , the characteristics of deformation and failure for tunnel lining were estimated, and the structural behaviors of deformed lining and the effects of repair and reinforcement for tunnel lining were researched.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.565-570
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• 2024

Recently, due to adjacent excavation work such as new buildings and common tunnel expansion concentrated around the urban railway, deformation of the underground box and tunnel structure of the urban railway built underground has occurred, and as a result, repair and reinforcement work is frequently carried. In addition, the subway is responsible for large-scale transportation, so ensuring the safety and drivability of underground structures is very important. Accordingly, an automated measurement system is being introduced to manage the safety of underground box structures. However, there is no analysis of structural damage vulnerabilities caused by subsidence or uplift of underground box structures. In this study, we aim to analyze damage vulnerabilities for safety monitoring of underground box structures. In addition, we intend to analyze major core monitoring locations by modeling underground box structures through numerical analysis. Therefore, we would like to suggest sensor installation locations and damage vulnerable areas for safety monitoring of underground box structures in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.6
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• pp.615-621
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• 2015

In this paper diamond wire cutting method has been proposed to cut the rock in the tunnel face. Diamond wire saw method could cut the rock from tunnel face with very minor vibration and noise. In this study rock cutting process has been simulated with FEM method by using LS-DYNA explicit non-linear finite element code. Normal load act as an prime factor when cutting the rock surface. For observing the effect of normal load on bead, several experiments has been conducted by varying normal loads on the bead. From each experiment, cutting rate has been calculated to compare the cutting rate with different load conditions. By increasing the normal load on bead, cutting rate increases drastically.

• Tunnel and Underground Space
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• v.16 no.5 s.64
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• pp.357-367
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• 2006

Recently, as the construction of new railway and the relocation of existing line increase, tunnel structures grow longer. The railway fire accidents in long tunnel bring large damages of human life and disaster. The interest of safety in long tunnel have a growing and the safety standard of long tunnel is tightening. For that reason, at the planning of long tunnel, the optimum design of safety facility in long tunnel for minimizing the risks and satisfying the safety standard is needed. For the reasonable design of long railway tunnel considering high safety, qualitative estimation for tunnel safety is required. In this study, QRA (Quantitative Risk Assessment) technique is applied to design of long railway tunnel for assuring the safety function and estimating the risk of safety. The case study for safety design in long railway tunnel is tarried out to verifying the QRA technique for two railway tunnels. Thus, the inclined and vertical shaft for escape way and safety facilities in long tunnel are planned, and the risks of tunnel safety for each case are estimated quantitatively.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.619-639
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• 2010

There is increasing interest in using structural monitoring as a cost effective way of managing risks once an area of concern has been identified. However, it is challenging to deploy an effective, reliable, large-scale, long-term and real-time monitoring system in an underground railway environment (subway / metro). The use of wireless sensor technology allows for rapid deployment of a monitoring scheme and thus has significant potential benefits as the time available for access is often severely limited. This paper identifies the critical factors that should be considered in the design of a wireless sensor network, including the availability of electrical power and communications networks. Various issues facing underground deployment of wireless sensor networks will also be discussed, in particular for two field case studies involving networks deployed for structural monitoring in the Prague Metro and the London Underground. The paper describes the network design, the radio propagation, the network topology as well as the practical issues involved in deploying a wireless sensor network in these two tunnels.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.768-769
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• 2009

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.3
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• pp.239-247
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• 2005

A new railway line of about 17km length was planned between Dongbaeksan and the neighboring town Dokye to improve the existing decrepit railway system. New line about 17km of the distance will almost be in circular alignment tunnels owing to the difference of elevation about 380m. Since the geology of the area is rather unusual compared to the normal in South Korea, extensive geological investigations have been carried out to prepare geological maps and profiles along the planned tunnel routes. The tunnel will almost be in sedimentary rock formations, such as limestone, sandstone, shale, coal etc and be near abandoned mines Various rock formations have the complicated, alter ed those rocks, but are well developed with laminated formations. Each rock formations have been classified using the Q-system and the cost of tunnel excavation, support has been estimated and compared for three alternative routes in the design stage. Based on these estimates, the final route of t he railway line was chosen.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.2
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• pp.117-125
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• 2015

Quantitative risk assessment (QRA) of railway is to create a variety of scenario and to quantify the degree of risk by a result of the product of accident frequency and accident. Quantitative risk Assessment is affected by various factors such as tunnel specifications, characteristics of the fire, and relation of smoke control and evacuation direction. So in this study, it is conducted that how the way of smoke control and the relation of smoke control and evacuation direction affect quantitative risk assessment with variables (the tunnel length (2, 3, 4, 5, 6 km) and the slope (5, 15, 25‰)). As the result, in a train fire at the double track tunnel (Area = $97m^2$), it is most efficient to evacuate to the opposite direction of smoke control regardless of the location of train in train fire. In addition, under the same condition, index risk in mechanical ventilation up to 1/10.

• Journal of Korean Tunnelling and Underground Space Association
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• v.26 no.5
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• pp.463-476
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• 2024

The shield TBM method can eliminate environmental hazards such as noise and vibration, and is environmentally friendly and allows safe tunnel construction even in soft ground conditions, but there are many restrictions on its application due to its high construction costs compared to the NATM. Therefore, in order to increase the applicability of the shield TBM method, it is necessary to ensure economic efficiency by reducing construction costs, and it is very important to reduce segment construction costs, which account for the largest proportion of shield TBM tunnel construction costs at about 35 to 40%. As part of this, this paper considers the changes in segment stress during tunnel construction and operation, tunnel external load conditions, etc. through analysis of long-term measurement data of shield TBMs in Japan, which has abundant experience in shield TBM construction, and compares and analyzes the differences between predicted values at the design stage and measured values during operation. Through this, we study improvements to ensure segment economic efficiency at the shield TBM design stage.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.462-469
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• 2011

The design of high-depth and large-section tunnel facilities has been increased lately. The purpose of the design is to avoid inference of existing facilities, enhance public relations and reducing the size of the station, which is advantageous for effective use of underground spaces. Diverse downtown tunnel experience, advanced excavation equipment, reinforcement methods, monitoring technologies and numerical analysis made the design possible. This paper is to introduce the design of high-depth and large-section tunnel facilities via Gimpo airport area of Deagok-Sosa railway BTL project of double-tracking.