• 한국터널지하공간학회 논문집
• /
• 제22권2호
• /
• pp.197-217
• /
• 2020

서울지하철 7, 9호선에 적용한 쉴드TBM은 소음 및 진동, 막장면의 안정성 확보 측면에서 발파공법에 비해 매우 안전한 공법이다. 또한, 쉴드TBM은 지반조건이 연약한 경우 효과적이다. 그러나 지반조건과 토피, 지하수 등의 여건에 적합하지 않은 장비를 적용할 경우 장비고장, 잦은 굴진중단, 특히 예상치 못한 불량한 지반을 통과하게 될 경우 터널 굴진 중 트러블이 발생할 수 있다. 본 논문은 일본 쉴드TBM 굴착중의 사고 및 트러블에 대한 사례를 정리하였다. 이중 대표적인 트러블 사례를 이용하여 지반변위 형상에 대한 실제발생 경향을 파악하였으며 수치해석을 통해 역해석결과와 상호비교하였다. 이를 토대로 막장 지보압을 산정할 경우 수치해석 적용시의 오차를 줄이는 방안을 제안하였다.

• 한국터널공학회:학술대회논문집
• /
• 한국터널공학회 2005년도 학술발표회 논문집
• /
• pp.225-232
• /
• 2005

The construction of parallel tunnel by using the shield TBM method was increased recently. Accordingly the application and the propriety of the parallel shield TBM tunnels were studied through domestic and foreign construction cases herein. Also the behavior of tunnel structure and ground was evaluated by a numerical analysis with various ground conditions and the distance between the parallel tunnels. As a result, it was concluded that a deep investigation as well as a ground reinforcement was required with a ratio(L/D) of the distance between the parallel tunnels(L) to tunnel outer diameter(D) less than 0.5 because the Interference phenomenon was expected to occur. And the appropriateness of the application method of parallel shield TBM tunnel was validated through the 2-dimensional numerical analysis simulated the process of excavation after the ground reinforcement in the starting area of the OOO construction site with the ratio(L/D) of 0.35.

• 한국전기전자재료학회논문지
• /
• 제19권3호
• /
• pp.273-279
• /
• 2006

High-$T_c$ superconducting (HTSC) power cable is one of the interesting parts in power application using HTSC wire. However, its stacked structure makes the current distribution between conducting layers non-uniform due to difference between self inductances of conducting layers and mutual inductances between two conducting layers, which results in lower current transmission capacity of HTSC power cable. In this paper, the transport current distribution between conducting layers was investigated through the numerical analysis for the equivalent circuit of HTSC power cable with a shield layer, and compared with the case of without a shield layer. The transport current distribution due to the increase of the contact resistance in each layer was improved. However, its magnetization loss increased as the contact resistance increased. It was confirmed from the analysis that the shield layer was contributed to the improvement of the current distribution between conducting layers if the winding direction and the pitch length were properly chosen.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
• /
• pp.535-538
• /
• 2004

Superconducting transmission power cable is one of interesting parts in power application using high temperature superconducting wire. One of important parameters in high-temperature superconduting (HTSC) cable design is transport current distribution because it is related with current transmission capacity and AC loss. In this paper, the transport current distribution at conducting layers was investigated through the analysis of the equivalent circuit for HTSC power cable with shield layer and compared with the case of without shield layer. The transport current distribution due to the pitch lenght was improved in the case of HTSC power cable with shield layer from the analysis.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2009년도 제38회 동계학술대회 초록집
• /
• pp.314-314
• /
• 2010

The design of the blanket and shield play a key role in determining the size of a reactor since it has an impact on the various reactor components. The blanket should produce enough tritium for tritium self-sufficiency and the shield should provide sufficient protection for the superconducting TF coil. Neutronic optimization of the blanket and the shield is necessary, and we coupled the system analysis with a neutronic calculation to account for the interrelation of the blanket and shield with the plasma performance of a reactor system in a self-consistent manner. By using the coupled system analysis code, the operational space for a low aspect ratio (LAR) tokamak reactor with a superconducting toroidal field (TF) coil is investigated with an spect ratio in the range of 1.5 - 2.5. The minimum major radius which satisfies all the physics and engineering requirements increases with the magnetic field at the magnetic axis. A required inboard shield thickness is mainly determined by the requirement on the protection of the TF coil against radiation damage. It is shown that to have a fusion power bigger than 3,000 MW in the LAR tokamak with a superconducting TF coil, a major radius bigger than 4.0 m is required.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 춘계학술대회 논문집
• /
• pp.1089-1090
• /
• 2012

• 한국터널지하공간학회 논문집
• /
• 제14권6호
• /
• pp.683-697
• /
• 2012

본 논문에서는 쉴드 TBM 터널에서 적용 가능한 리스크 분석 방법을 연구하였다. FTA 방법을 통해 리스크 아이템과 각각의 발생확률을 확인하고 AHP 방법을 통해 각각의 리스크 아이템의 영향도를 구하였다. 마지막으로 각각의 리스크 아이템의 리스크 레벨을 평가할 수 있었다. 개발된 방법을 EPB 쉴드 터널이 사용된 서울 지하철 현장에 적용하여 리스크 분석 결과가 현장 데이터에 부합하는 합리적 결과임을 검증하였다.

• 한국터널지하공간학회 논문집
• /
• 제16권2호
• /
• pp.213-224
• /
• 2014

최근, tunnel boring machine (TBM)을 이용한 도심지 지중 전력구 터널 건설이 증가하고 있다. 쉴드 TBM을 이용한 기계화 터널 굴착 공법은 재래식 공법에 비해 지반침하를 최소화 하고 발파에 의한 진동을 줄일 수 있는 장점이 있다. 국내에서는 earth pressure balance(EPB) 쉴드 TBM이 주로 사용되고 있다. 그러나 전력구 터널 굴착을 위한 쉴드 TBM 공법이 증가함에도 불구하고, 전력구 쉴드 TBM 터널의 거동 분석에 관한 연구는 미비한 실정이다. 본 연구에서는 후방주입 거리에 따른 전력구 쉴드 TBM 터널의 거동 특성을 분석하고, 굴착면 지반 손실과 후방주입 거리와의 상관관계를 도출하고자 한다. 쉴드 TBM을 이용한 터널 굴착은 3D FEM을 이용하여 시뮬레이션 하였다. 뒷채움 그라우트가 설치되는 거리의 변화에 따른 축력, 전단력, 휨 모멘트와 같은 단면력을 검토하고 지표면에서의 연직 변위를 분석하였다. 또한, 유한요소해석으로 얻어진 결과와 안정성 분석에 기초하여, 지반과 터널 구조물의 안정성을 확보할 수 있는 뒷채움재 주입시기를 결정할 수 있다.

• Nuclear Engineering and Technology
• /
• 제50권1호
• /
• pp.170-181
• /
• 2018

Because of the design and construction requirements, the nuclear structures need to maintain the structural integrity under both design state and extreme earthquake shaking. The base-isolation technology can significantly reduce the damages of structures under extreme earthquake events, and effectively protect the safeties of structures and internal equipment. This study proposes a base-isolation design for the AP1000 nuclear shield building on considering the performance requirements of the seismic isolation systems and devices of shield building. The seismic responses of isolated and nonisolated shield buildings subjected to design basis earthquake (DBE) shaking and beyond-design basis earthquake (BDBE) shaking are analyzed, and three different strategies for controlling the displacements subjected to BDBE shaking are performed. By comparing with nonisolated shield buildings, the floor acceleration spectra of isolated shield buildings, relative displacement, and base shear force are significantly reduced in high-frequency region. The results demonstrate that the base-isolation technology is an effective approach to maintain the structural integrity which subjected to both DBE and BDBE shaking. A displacement control design for isolation layers subjected to BDBE shaking, which adopts fluid dampers for controlling the horizontal displacement of isolation layer is developed. The effectiveness of this simple method is verified through numerical analysis.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2011년도 춘계학술대회 논문집
• /
• pp.1509-1518
• /
• 2011

Shield TBM tunneling method has been getting the spotlight for urban tunneling. It can be minimized the civil complaint during construction and possible safe tunneling. But the settlement has occurred inevitably due to characteristics of shield TBM equipment. For this reason, the civil complaint can occur in urban areas when tunnel with shallow depth passes through neighboring building or residential area. In this study, the occurrence factors of settlement according to shield TBM tunneling and the tendency of ground settlement by strata condition had analyzed. It is suggested that the practical settlement estimation method and minimizing method of ground settlement under simultaneous backfill grouting condition through measurement results and back analysis data using gap parameter.