• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.393-404
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• 2018

The tunnel can be planned to connect to underground roadway and surface road. The large tunnel and branch section are made when the ramp tunnel access to the main tunnel. In the branch section, stress concentration can be assigned and it can be very important for the stability of the tunnel. This study assessed the behavior of rock pillar in double deck tunnel diverging area by using a two dimensional numerical analysis. This study evaluated different safety factors according to pillar width and the ramp tunnel position in branch. By the assessment of the strength-stress ratio, tunnel pillar width is suggested in order to secure the safety factor 1.5.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.2
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• pp.135-141
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• 2002

This research has been conducted to investigate the influence of mined cavities on a tunnel to be constructed around a coal mine. The location and dimension of cavities were supposed by analysing synthetically geological structures and condition of coal beds as well as gangway map since there does not exist any map describing mined cavities. Detailed geological and geophygical survey have also been carried out for the purpose of understanding the geological structure and rock mass conditions. The two dimensional numerical analysis with FLAC has been performed on the geological sections reconstituted from the obtained information and the affects of mined cavities on the tunnel have been assessed.

• Journal of the Earthquake Engineering Society of Korea
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• v.4 no.3
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• pp.107-115
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• 2000

충적지반에 건설된 원형 단면을 갖는 터널은 지진시에 지반의 전단 변형의 영향을 받아 좌우교차로 경사진 타원형상의 변형을 반복한다. 본 논문에서는 이 특별한 진동모드를 이용하여 지반-터널계의 상호작용 및 면진 효과가 검토되었다. 지반과 터널의 경계가 완전히 결합되어 있는 경우에 대한 지반 -터널계의 상호작용 효과 및 지하 구조물의 지진피해를 줄이는 한가지 방법으로써 터널 주위를 면진재로 피복하는 방법에 대한 면진효과가 토론되었다. 그 결과 면진재의 포아송비를 작게 하거나 지반과 면진재의 전단탄성계수의 비를 증가시킴으로서 면진 효가가 증가함을 알 수 있었다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3C
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• pp.219-228
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• 2006

In this study, a series of fire tests was carried out to evaluate fire-induced damage to structural members in tunnels. From the tests, the loss amount of concrete materials under the RWS scenario was slightly bigger than under the RABT fire scenario. Especially under the RWS fire scenario where the maximum temperature is over $1,200^{\circ}C$, the loss of concrete materials was mainly induced by melting. Generally, the loss of materials in reinforced concrete was slightly smaller than that in unreinforced concrete. Depending upon an applied fire scenario, fire-induced damage to shotcrete was quite different. From the realtime investigation of a specimen surface by a digital camcorder, it was proved that the material loss under the RABT fire scenario was mainly induced by spalling. However, it was also revealed that although fire-induced damage in the initial heating stage under the RWS was so close to that under the RABT, the material loss under the RWS at the later stage after 50 minutes elapsed since fire initiation was induced not by spalling but by melting.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.6
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• pp.653-666
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• 2012

This study made progress about Demage Mechanism of Transition Section in Cut and Cover Tunnel. For this study, Inspection and test was carried out about Transition Section. After this process, Numerical Analysis was accomplished by 2D, 3D. A result of inspection and test, It couldn't find the reason why the upper slab Demage was detected. So 2D Numerical Analysis was conducted. It was analyzed that the Safety Factor(1.0) was satisfied in 2D. But, the result of 3D Numerical Analysis, The reason was found that the Demage on upper slab was caused by moment change. The Moment was changed by column interval transition. For Retrofitting, Column was added under slab in tunnel. It was found that the addition column decreased upper slab deformation. After this study, It could be find that are important 3D Numerical Analysis as well as 2D Numerical Analysis in case of Transition Section. This Study can help developing construction and maintenance about Tunnel. Finally, It's going to study Retrofitting plans which have minimum influence of Transition Section in Cut and Cover Tunnel.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.6
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• pp.637-652
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• 2012

The protector with the shape of '${\sqcap}$' in cross section can be set up in the tunnel, which can be constructed for enlargement of cross section, to keep traffic flow in the tunnel. It is impossible to install the rockbolt in the side wall of tunnel due to a limited space between the protector and cutting surface of side wall. The objective of this study is to suggest the optimum thickness of shotcrete lining without rockbolt on the side wall and to evaluate the stability of tunnel enlarged. Numerical analysis was performed to evaluate the displacement at the center of tunnel, the convergence of tunnel, and the stress in shotcrete lining in 4-lane NATM road tunnel enlarged from 3-lane NATM road tunnel. The vertical displacement at the center of tunnel and the convergence of crown in the tunnel with rockbolt in the side wall were almost similar to those in the tunnel without rockbolt in the side wall. The convergence of bench/invert and the stress in shotcrete lining without rockbolt on the side wall were greater maximum 0.57 mm and 1,300 kN/$m^2$ than those with rockbolt in the side wall. The increased convergence and the stress in shotcrete lining can be reduced in incerasing of thickness of shotcrete lining about 20% (5 cm) of standard thickness, 25 cm, of shotcrete lining.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1996.03a
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• pp.25-34
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• 1996

터널은 긴 선상구조물로서 사전지질조사에 의해 설계에 필요한 정보를 정밀도 높게 구하는 것이 매우 어렵다. 따라서 터널시공 중 암반 및 지질상황을 관찰하고, 터널주변 지반의 거동을 계측하여 지반에 적합한 지보공을 설계ㆍ시공하는 것이 필수적이다. 이를 위해서 터널시공 중 정량적인 암반분류와 계측(일상관리계측과 대표단면계측)이 주기적으로 실시되고 있지만, 이러한 결과를 어떻게 시공에 반영하느냐는 터널의 합리적인 시공에 있어 매우 어려우면서도 중요한 문제라 할 수 있다. (중략)

• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.202-212
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• 2005

배수식 방수방식으로 지하 30m에 건설된 NATM터널 통신구를 준공 7년후 완전방수식 방식으로 변경하였다. 터널 라이닝에 30m의 수압을 작용할 경우 발생하는 단면력을 구조검토하고 배근상태가 안전한가 분석하였다. 또한 라이닝의 시공단면을 확인하기 위하여 충격반향기법(Impact-Echo Method)탐사와 GPR탐사, 배근상태를 파악하기 위하여 철근탐지기를 사용하였다. 그 결과 30m 수압에 안전할 것이라는 판단하에 배면주입 방수공법을 적용 통신구를 완전방수 하였다. 그리고 배수식 통신구를 운용하는 비용과 완전방수공사비를 분석한 결과 배출되는 지하수량이 많은 경우 완전방수시공이 경제성이 있다고 분석되었다.

• Explosives and Blasting
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• v.14 no.2
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• pp.63-70
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• 1996

This paper describes the method used to determine the optimal section for the horseshoe shaped single tunnel which is utitized widely in constructing subway tunnels. Vehicle and structural gauges conform to the design criteria for the Seoul Subway Line 5. The tunnel sections are determined considering the structural stability, and the tunnel excavation area is optimized so as to minimize design and construction costs.

• Magazine of korean Tunnelling and Underground Space Association
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• v.13 no.4
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• pp.47-63
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• 2011