• Explosives and Blasting
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• v.14 no.1
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• pp.31-48
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• 1996

• Journal of the Korean Geosynthetics Society
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• v.15 no.2
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• pp.55-64
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• 2016

The construction of the road NATM tunnel, which undergoes the weathered zone of the mountain, was in process with the reinforcement methods such as the rock bolt, shotcrete depositing, and the multi step grout with large diameter steel pipe. The collapse from the ceiling, and on the ground surface area(sink hole), of which were measured to be 25m from the ground surface($V=12m(W){\times}14m(L){\times}5m(H)=840m^3$), as well as excessive displacements in the tunnel, had occurred. In order to execute the necessary reconstruction work, the causes of the surface collapses were inspected through the field investigation, in-situ tests, and numerical analysis. As a result, several proper solutions were suggested for both internal and external reinforcements for the tunnel. As a result of numerical analysis, the collapsed zone of the tunnel was reinforced up to 0.5D~1.0D laterally by the cement grouting on the ground surface, 0.5D longitudinally by the multi step grout with large diameter steel pipe in tunnel. With further reinforcement implemented by rebars in lining, the forward horizontal boring was executed to the rest of the tunnel to evaluate the overall status of the tunnel face. Appropriate reinforcement methods were provided if needed.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.4
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• pp.285-303
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• 2023

Interest in building underground spaces is increasing for the creation of downtown infrastructure and efficient space utilization. A representative method of utilizing underground space is a tunnel, and in addition to road tunnels, the construction of utility tunnels such as power conduits and utility conduits is gradually increasing. The current basic tunnel construction method can be divided into NATM (New Austrian Tunnelling Method) and TBM (Tunnel Boring Machine). The NATM is a reliable method, but it is accompanied by vibration and noise due to blasting. In the case of the TBM excavation method, there are disadvantages in terms of construction period and construction cost, but it is possible to improve economic feasibility by introducing appropriate complementary methods. In this study, a blasting method was develop using the NATM after TBM pre-excavation using the protective shield method. This is a method that compensates for the disadvantages of each tunnel construction method, and is expected to reduce construction costs, blasting vibration, and noise. In order to review the performance of the developed method, an experiment was conducted to evaluate the performance of explosion-proof tube to which a protective shield scale model was applied, and the impact of blasting vibration of the protective shield method was analyzed.

• Magazine of korean Tunnelling and Underground Space Association
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• v.1 no.2
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• pp.161-170
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• 1999

본고에서는 $1986.8\~1988.7$월중에 시공된 부산지하철 1호선 3단계 건설구간 중 서대신동 로타리에서 괴정국민학교 앞까지 연${\cdot}$경암지역에서의 TBM(Tunnel Boring Machine)으로 시행된 단선터널(7.0m)과 NATM으로 시행한 복선터널의 근접시공에 따른 간벽부 보강설계 내용과 근접부 시공시 계측결과 분석, 지보 Pattern조정 및 시공 실적 등을 제시하였다. 원설계 내용 분석 결과 지보 Pattern이 현장 지반조건에 비해 과다하였고 TBM 굴진시 Thrust 2500kN(본 기계 기준) 이상인 연암이상의 지반에서는 TBM 굴착으로의 효율성이 있었고, 경암구간에서 병행터널의 간섭영향을 배제하려면 터널간의 중심거리가 터널직경의 2배 이상이 되어야 하며, TBM 단선터널(7.0m)의 일 평균 굴진 길이는 4.6m로 분석되었다. 앞으로 이와 유사한 암층에서의 터널근접 시공 및 TBM 굴착시 본 분석내용이 참고가 되기를 기대하여 본고를 작성하였다.

• Proceeding of EDISON Challenge
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• 2017.03a
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• pp.330-332
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• 2017

본 논문에서는 숏크리트 지보재의 시간 의존적 경화특성을 고려한 터널 지보재의 3차원 유한요소해석을 수행하였다. NATM터널에 대한 기존 숏크리트 지보재 해석방식에 의한 결과화 제안된 시간 의존적 해석방법의 결과를 비교함으로서, 시간의존적 특성이 숏크리트 지보재의 응력 및 내공변위에 미치는 영향을 분석하였다. 시간 의존적 특성을 고려한 3차원 해석방법이 숏크리트 지보재의 변형을 과소평가 할 수 있음을 확인하였다.

• Magazine of korean Tunnelling and Underground Space Association
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• v.4 no.4
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• pp.95-116
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• 2002

• Magazine of korean Tunnelling and Underground Space Association
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• v.1 no.2
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• pp.81-91
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• 1999

• Magazine of korean Tunnelling and Underground Space Association
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• v.11 no.1
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• pp.60-77
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• 2009

• Tunnel and Underground Space
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• v.9 no.3
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• pp.204-213
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• 1999

NATM(New Austrian Tunnelling Method) uses a support system of shotcrete, rockbolt and steel support, which are installed after tunnel excavation. Recently, a lattice girder among these support system is used in tunnelling. A lattice girder is a new steel support developed in Europe for the replacement of an existing H-shaped steel set, which is reported to have some problems in installation. This is a triangular shape welded with steel rods and is a light-weight support system which enables fast and easy installation of porepolling. The major advantage of a lattice girder is the good bonding with shotcrete. In this study, to evaluate the applicability of a lattice girder in tunnelling in Korea, field tests were performed at a high speed railway tunnel with a large section. Also, features of lattice girder in field tests were compared with those of a H-shaped steel set respectively. Field tests proved that a lattice girder fully supported the initial earth pressure developed right after excavation and limited ground deformation effectively.

• 한국도로학회:학술대회논문집
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• 2009.11a
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• pp.237-250
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• 2009