• Journal of the Korean Geotechnical Society
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• v.27 no.11
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• pp.47-54
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• 2011

In this paper, longitudinal behaviors of a tunnel with respect to various conditions are analyzed, and a new equation of longitudinal deformation curve during tunnel expansion is proposed. Finally, the range of protection by a protector is investigated using the proposed equation. To achieve the objectives, numerical analysis according to the ground and expansion conditions is performed. The results show that the range of protection, when a 2 traffic lane tunnel is expanded to 4 traffic lanes, should cover at least 24m to backward and 35m forward.

• Tunnel and Underground Space
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• v.34 no.2
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• pp.143-153
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• 2024

Tunnel Boring Machine (TBM) method is a tunnel excavation method that produces lower levels of noise and vibration during excavation compared to drilling and blasting methods, and it offers higher stability. It is increasingly being applied to tunnel projects worldwide. The disc cutter is an excavation tool mounted on the cutterhead of a TBM, which constantly interacts with the ground at the tunnel face, inevitably leading to wear. In this study quantitatively predicted disc cutter wear using geological conditions, TBM operational parameters, and machine learning algorithms. Among the input variables for predicting disc cutter wear, the Uniaxial Compressive Strength (UCS) is considerably limited compared to machine and wear data, so the UCS estimation for the entire section was first conducted using TBM machine data, and then the prediction of the Coefficient of Wearing rate(CW) was performed with the completed data. Comparing the performance of CW prediction models, the XGBoost model showed the highest performance, and SHapley Additive exPlanation (SHAP) analysis was conducted to interpret the complex prediction model.

• Tunnel and Underground Space
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• v.17 no.1 s.66
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• pp.26-31
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• 2007

The 11 nuclear power plants have been taking charge of more than 40% of the total electrical power development in Korea. In addition to the existing nuclear power plants at Gori, Wolsung, Youngkwang, etc., the 12 nuclear power plants are expected to be newly established until 2006. So, the 23 nuclear power plants will produce the electric power as much as more than 50% of the national gross production. However the nuclear power plants are inevitably generating the detrimental atomic wastes. Therefore the disposal techniques for the nuclear wastes should be ensured considering a very high safety factor. According to the basic researches in KAERI, the underground disposal repositories are reported to be most favorable for Korea. The KBS-3 disposal system has been strongly suggested by KAERI and this system has a deep tunnel with several disposal boreholes in tunnel floor. The nuclear wastes, which are sealed tightly in a canister, will be disposed in these boreholes. Considering the disposal tunnel in a great depth, the in-situ stress regimes will affect severely the tunnel stability. Consequently the effect of the in-situ stresses on the disposal tunnel and the role of the in-situ stresses in tunnel stability analysis are examined by the numerical studies.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.507-515
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• 2016

In South Korea, there are a large number of tunnels because of the mountainous terrain, and to overcome this characteristics, lengths of tunnels are more longer than existing tunnels. The need to improvement current tunnel management contents is giving rise for accidents in tunnel section is continuously increased although lots of efforts to reduce the accidents. Conventionally, disaster prevention have been focused on the Tunnel Management Systems, tunnel operators generally tend to depend on CCTV images for most contents of detailed traffic flow managing. In this paper, investigation about current Tunnel Management Systems contents using IPA survey was conducted, and Priority Improvement Contents(Accident Situation Management Support, 2nd Accident Management Support, Traffic Flow Monitoring), which importance are high, but satisfaction are low, are deducted. Also, CCTV images, lack intuitive understanding, are judged as a main cause of low satisfaction of those contents. To overcome those limitations of the existing Tunnel Management Systems, this study sought to develop a technology for the synthesis of road images to derive traffic information from synthesis images, and the contents improvement stragegy is established. Tunnel operators-oriented satisfaction survey on new contents was carried out, and scored 4.2 on a 5-point scale. This has confirmed that the availability of new contents and at this stage, with pushing ahead of long-tunnels and undersea tunnels construction, politic applications are expected.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.40 no.4
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• pp.11-17
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• 2011

적정한 환기용량의 산정과 최적의 환기방식선정으로 공사비를 절감하고, 운영 중의 안전성도 확보하는 방안을 소개하고자 한다.

• Korean Journal of Construction Engineering and Management
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• v.18 no.4
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• pp.36-47
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• 2017

As a typical domestic subsea tunnel construction the Gadeok subsea tunnel applying the method of immersed tunnel has been completed and the Boryeong-Taean subsea tunnel is under construction using NATM. The high-speed railway subsea tunnels between the Honam and Jeju are under consideration, and the feasibility of constructing subsea tunnels with Japan and China is also under consideration. However, it is difficult to provide the process plan information for the construction work such as the analysis of the feasibility of the subsea tunnel and the prediction of the proper construction period because there is no case of domestic construction for it applying the shield TBM method. Due to economic and other reasons, government organizations are reluctant to apply the shield TBM, and there is lack of data on the construction process management field using the shield TBM method. Therefore, a standard construction process management system for the subsea tunnel is needed to analyze the feasibility of the subsea tunnel and to predict the proper construction period. By presenting the standard construction process management system of subsea tunnels such as WBS, Network Diagram, and construction period calculation model, I hope to contribute technically and economically to future subsea tunnel projects.

• Journal of Korean Tunnelling and Underground Space Association
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• v.10 no.1
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• pp.1-15
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• 2008

Recently, because of the various factors by uncertainty of underground, the risks in tunnelling have been occurred increasingly. Therefore, it is very important to estimate and control the risks considering geotechnical conditions for tunnel stability and environmental problems by tunnel construction. In this study, the risk analysis for tunnel stability was carried out by classifying the risk factors such as ground support capacity, ground settlement, the inflow of groundwater into the tunnel and the damage by the earthquake. Also, the risk assessment for the environmental problems was performed by calculating the vibration and noise by blasting and the drawdown of the groundwater level caused by tunnel construction. Each risk factor was evaluated quantitatively based on the probabilistic and statistic technique, then it was analyzed the distribution characteristic along overall tunnel site. Finally, it was evaluated that how much each risk factor influences on the construction cost with a period for tunnel construction, so it is possible to perform reasonable tunnel design which was capable of minimizing the risks in the tunnel construction.

• Tunnel and Underground Space
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• v.17 no.2 s.67
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• pp.152-164
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• 2007

Recently as increasing the amounts of cargoes and passengers, it is necessary to improving railway capacity and speed. So the constructions of improving the existing railway line have been advanced. Sometimes the new railway tunnel is built to adjacent the existing railway line. Furthermore the new tunnel might be built near the existing facility within the tunnel width. In this case, it should be analyzed the influence of existing tunnel and if it is necessary, it should be taken the appropriate counterplan. The major analysis contents are follows. One is the influence on the existing tunnel by a blasting and train vibration and the other is stability problem of the existing tunnel by excavation of new tunnel. Therefore, we peformed the following analysis. Refer to a domestic and foreign standard and paper, the permitting level of blasting vibration is decided and the excavation plan of the new tunnel are designed. The numerical analysis is performed about the stability of the existing tunnel and new tunnel. The influence of the train vibration on tunnel is analyzed by the empirical equation.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.334-337
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• 2006

현재 전 세계는 IPv4 주소 자원의 고갈에 대비한 IPv6의 도입을 위해 국가 차원의 전략적인 노력을 기울이고 있으며, 이에 따라 IPv4망에서 IPv6망으로의 안정적인 전이를 위한 상호 운영기술이 지속적으로 개발되고 있다. 이러한 기술을 적용하기 위한 다양한 응용 프로그램의 운영을 위해서 IPv6 기반의 DNS 기술은 그 핵심적인 요소라 할 수 있다. 그러나 현재 IPv4로 이루어져 있는 환경에서 바로 IPv6 환경으로의 변경이 어렵기 때문에 IPv6 네트워크 환경으로의 전이 과정에서 발생되는 IPv4와 IPv6의 네트워크의 공존 환경에서 트래픽을 안정적으로 전달하기 위한 기술이 필요하게 되었다. 이런 IPv4와 IPv6 상호 운용 기술을 이용하여 본 논문에서는 IPv4와 IPv6가 혼재한 망에서 안정적인 IPv6 Recursive DNS을 구성하기 위하여 상호 운용 기술 중 터널링 기술을 이용한 IPv6 Recursive DNS 구성 방안을 제시하여 혼재한 IPv4 와 IPv6 DNS를 운영하기 위한 구성모델을 제안한다.

• Tunnel and Underground Space
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• v.33 no.6
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• pp.445-471
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• 2023

Long-term safety over millennia is the top priority consideration in the construction of disposal sites. However, ensuring the mechanical stability of deep geological repositories for spent fuel, a.k.a. radwaste, disposal during construction and operation is also crucial for safe operation of the repository. Imposing restrictions or limitations on tunnel support and lining materials such as shotcrete, concrete, grouting, which might compromise the sealing performance of backfill and buffer materials which are essential elements for the long-term safety of disposal sites, presents a highly challenging task for rock engineers and tunnelling experts. In this study, as part of an extensive exploration to aid in the proper selection of disposal sites, the anticipation of constructing a deep geological repository at a depth of 500 meters in an unknown state has been carried out. Through a review of 2D and 3D numerical analyses, the study aimed to explore the range of properties that ensure stability. Preliminary findings identified the potential range of rock properties that secure the stability of central and disposal tunnels, while the stability of the vertical tunnel network was confirmed through 3D analysis, outlining fundamental rock conditions necessary for the construction of disposal sites.