• 터널과지하공간
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• 제18권6호
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• pp.491-502
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• 2008

터널 주위에 다른 구조물이 인접하여 건설될 때 터널의 구조적인 안정성을 확보하기 위해서는 주변 지반의 일정범위를 원상태로 보전하여야 하며, 이와 같은 범위를 터널의 안전영역이라고 한다. 터널 교차지역에서 새로운 터널이 건설될 때 기존터널의 안정성을 확보하기 위한 주요 요인은 터널간 이격거리, 새로운 터널의 규모 및 굴착방법, 터널 주변지반의 조건, 기존터널의 라이닝 구조와 건전도 등이며, 새로운 터널이 기존터널의 상부에 근접하여 교차하는 경우 기존터널은 새로운 터널 방향으로 기존터널 상부에서 변형이 발생하고, 기존터널 주변지반의 아칭효과 손상, 그리고 새로운 터널에서의 활하중의 영향 등을 받게 된다. 반면에 새로운 터널이 기존터널 하부에서 굴착되는 경우 기존터널은 침하의 영향을 받게 된다. 본 연구는 새로운 터널이 기존터널의 하부에서 굴착될 때 수치해석을 통하여 안전영역을 평가하였으며, 모형실험을 통하여 지반의 거동특성을 파악하였다. 모형실험과 수치해석에 의하여 토압의 변화, 지반변위 및 내공변위를 상호 비교하였으며, 유사한 경향을 보이고 있다.

• 한국농림기상학회지
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• 제2권3호
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• pp.87-94
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• 2000

지역과 육묘시기에 알맞은 기계이앙상자육묘 보온못자리의 피복자재와 못자리양식을 선정하기 위하여 PE 필름터널, 부직포터널. 부직포평상 못자리에 대한 상내미기상과 외부기상의 영향을 조사하였다. 1. 맑은 날 포차(vapor pressure deficit)는 낮에는 대기보다 부직포터널과 PE필름터널의 내부가 더 컸고, 흐리거나 비가 온 날은 낮에 부직포터널이 PE필름터널이나 외부보다 컸다. 2. 하루동안 지중열류량은 PE필름터널, 부직포평상, 부직포터널 순으로 대기중으로 방출하는 에너지보다 지중으로 흡수하는 에너지가 많았다. 흐리거나 비 온 날은 부직포평상과 부직포터널은 대기중으로 방출하는 에너지보다 지중으로 흡수되는 에너지가 더 컸으나, PE필름터널은 대기중으로 방출하는 에너지가 컸다. 3. 온도의 수직분포는 날씨에 관계없이 낮에는 역전 상태를 보였고, 일몰 이후부터 아침까지는 감률상태이었다. 4. 최고기온은 맑은 날 PE필름터널에서 외부기온보다 21.1$^{\circ}C$ 높은 47.2$^{\circ}C$이었고, 부직포터널은 10.9$^{\circ}C$ 높은 37.$0^{\circ}C$이었다. 흐린 날 외부기온보다 PE필름터널은 8.1$^{\circ}C$ 높고, 부직포터널에서는 4.$0^{\circ}C$높게 나타났다. 최저기온은 날씨에 관계없이 0~0.4$^{\circ}C$ 이내로 차이를 보이지 않았다. 일교차는 외부기온, 부직포 터널, 비닐터널 순서로 커지는 경향이었다. 5. 모의 소질은 부직포터널이 부직포평상 또는 PE필름터널보다 충실하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.59.1-59.1
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• 2011

In this research, CFD calculation was implemented to analyze wind tunnel effect or rotor experiment in wind tunnel. One case included model wind turbine and all wind tunnel geometries. The other case include only rotor and nacelle system. Star-CCM+ was used for CFD analysis and rigid body motion around rotor area was applied to simulate rotating rotor. As for turbulence model, K-omega SST was used. The results were compared in 15m/s inflow condition. These results shows a good agreement with the measurement. Then, the result without wind tunnel was slightly different to the result with wind tunnel. Thus, in the case of Mexnex wind tunnel measurement, the wind tunnel don't affect the measurement result. Then, this wind tunnel and rotor size ratio can be reference for wind tunnel experiment of wind turbine rotor.

• Journal of Advanced Marine Engineering and Technology
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• 제31권5호
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• pp.614-621
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• 2007

The fishing boat propulsion system employing the modified stern shape and the tunnel to protect a propeller is developed to increase the cruise speed and reduce he problem resulting from the open propeller accidentally catching the waste net and able on the sea. Using 3 different tunnel types, the model test was performed in the circular water channel and the panel method based on the potential theory is applied to analyze the open water performance of the propeller. In the numerical analysis using he potential-based panel method, it calculates the hydrodynamic interaction between the propeller and the tunnel and evaluates the effect of the tunnel geometry. From the numerical and experimental results differing tunnel geometries, the propulsion efficiency is increased by the larger diameter of the inlet than the outlet of the tunnel and the smaller gap between the propeller tip and the tunnel internal surface. These results provide the information of the propeller system with the tunnel and the hydrodynamic interaction between the propeller and the tunnel.

• 한국철도학회논문집
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• 제8권6호
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• pp.513-519
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• 2005

The Korean Tilting Train eXpress may produced a strong micro-pressure wave in tunnel exit because of large train/tunnel area ration of conventional railways. This micro-pressure wave causes an impulsive noise which is a serious environmental noise pollution near tunnel exit. Tunnel hood can be the method of reducing the micro-pressure wave in tunnel exit. Therefore, parametric studies for tunnel hood are performed with respect to the hood length and size to investigate the effects of the tunnel hood. Also, axi-symmetric unsteady compressible flow solver was used to analyze train-tunnel relative motion. According to the result of numerical analysis, the maximum micro-pressure wave in tunnel exit is reduced by 56% throughout the hood establishment on conventional railways.

• 한국유체기계학회 논문집
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• 제14권4호
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• pp.25-30
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• 2011

The jet fan is generally used to add thrust in the longitudinal ventilation system of road tunnel and the geometric conditions of jet fan such as the distance from tunnel wall have an effect on the performance of ventilation system. Numerical analyses on the flow in tunnel caused by operation of jet fan are presented to study the ventilation characteristics in tunnel. While the distance between jet fans in parallel installed in tunnel is changed 0.5 L/D to 3.0 L/D, the flowrate and mean velocity through tunnel are calculated for each cases. As the distance between jet fans increases, the flowrate through tunnel increases asymptotically and the momentum of tunnel flow is alike.

• Industrial Engineering and Management Systems
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• 제3권1호
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• pp.59-62
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• 2004

The number of tunnel has fast increased with the rapid expansion of highway network. Tunnel should be designed to provide for drivers both safety and pleasant driving conditions. In this perspective, the design for tunnel lightning is very important in order to provide its safety, pleasantness, and cost-efficiency of maintenance, all of which should be considered and analyzed for a better tunnel lighting. This paper attempts to compare the low-pressure sodium lamp, which have usually been used for tunnel lighting, with the fluorescent lamp, which we consider as an alternative for the former. In an effort to determine the number of lamps to meet the required illuminance in the tunnel, this research employs a simulation technique which would allow us to conjecture, with the aid of basic model, the life cycle cost for illumination per each tunnel. This analysis is expected to provide a basic method and related information for tunnel development and design.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 추계 학술발표회
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• pp.56-65
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• 2006

계획된 터널 갱구부에서 일부 구간(28m)이 용도폐기된 터널과 교차하여 안전한 시공을 위한 대책방안이 요구되었다. 폐터널은 계획터널과 계획고가 거의 같은 상태에서 경사교차하여 계획터널의 시공 중 안정성과 영구 안정성에 큰 위해 요소가 되었다. 본 터널 벽면을 관통하여 지반에 위치한 폐터널의 일정 구간을 버력과 시멘트 밀크 그라우팅으로 밀실하게 채워 안정성을 확보하였다. 되메움 후 폐터널 교차 구간 시공 시 그라우팅 core를 획득하여 물성시험을 통해 시공품질을 확인하였고, 시공 중 계측을 통해 안정성을 확인하였다.

• Geomechanics and Engineering
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• 제15권2호
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• pp.721-728
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• 2018

The surrounding rock mass contains cracks and joints which are distributed randomly around tunnels, and in the process of tunnel blasting excavation, radial cracks could also be induced in the surrounding rock mass. In order to clearly understand the impact of radial cracks on tunnel stability, tunnel model tests and finite element numerical analysis were implemented in this paper. Two kinds of materials: cement mortar and sandstone, were used to make tunnel models, which were loaded vertically and confined horizontally. The tunnel failure pattern was simulated by using RFPA2D code, and the Tresca stresses and the stress intensity factors were calculated by using ABAQUS code, which were applied to the analysis of tunnel model test results. The numerical results generally agree with the model test results, and the mode II stress intensity factors calculated by ABAQUS code can well explain the model test results. It can be seen that for tunnels with a radial crack emanating from three points on tunnel edge, i.e., the middle point between tunnel spandrel and its top with a dip angle $45^{\circ}$, the tunnel foot with a dip angle $127^{\circ}$, and the tunnel spandrel with $135^{\circ}$ with tunnel wall, the tunnel model strength is about a half of the regular tunnel model strength, and the corresponding tunnel stability decreases largely.

• Geomechanics and Engineering
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• 제35권4호
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• pp.395-409
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• 2023

Long-span suspension bridges have tunnel anchor systems to maintain stable cables. More investigations are required to determine how closely tunnel excavation beneath the tunnel anchor impacts the stability of the tunnel anchor. In order to investigate the impact of the adjacent tunnel's excavation on the stability of the tunnel anchor, a large-span suspension bridge tunnel anchor is utilised as an example in a three-dimensional numerical simulation approach. In order to explore the deformation control mechanism, orthogonal tests are employed to pinpoint the major impacting elements. The construction of an advanced pipe shed, strengthening the primary support. Moreover, according to the findings the grouting reinforcement of the surrounding rock, have a significant control effect on the settlement of the tunnel vault and plug body. However, reducing the lag distance of the secondary lining does not have such big influence. The greatest way to control tunnel vault settling is to use the grout reinforcement, which increases the bearing capacity and strength of the surrounding rock. This greatly minimizes the size of the tunnel excavation disturbance area. Advanced pipe shed can not only increase the surrounding rock's bearing capacity at the pipe shed, but can also prevent the tunnel vault from connecting with the disturbance area at the bottom of the anchorage tunnel, reduce the range of shear failure area outside the anchorage tunnel, and have the best impact on the plug body's settlement control.