• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.2
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• pp.197-217
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• 2020

Shield TBM tunneling, used in the construction of Seoul subway line 7 and line 9, has been well known as a very efficient, as well as safe, tunneling method. Although the Shield TBM method has been known to be effectively used in poor ground conditions, a number of troubles have occurred during the use of the shield TBM, due to inappropriate machine selection, machine breakdown, and unpredicted ground conditions etc. In this study, several accidents and trouble cases occurred during excavation by Shield TBM, reported from Japan, were investigated. A series of numerical analysis was then performed to compare with the trouble cases and back-analysis results for the cause analysis. The lessons learned from the case studies are presented at the end.

• Tunnel and Underground Space
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• v.33 no.4
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• pp.255-264
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• 2023

As the demand for urban underground space increases recently, urban tunnel planning is actively progressing. In the urban area, a underground station is planned in consideration of the living environment of residents, and 2-arch tunnel is applied for the stability of existing structures and reduction of environmental damage. However, since the depth of weak rock mass is deeply distributed in the urban area due to severe weathering, careful planning is required to secure tunnel stability. In addition, if TBM mechanical excavation is applied as the main tunnel excavation method considering the composite ground in urban area, the construction connectivity with the 2-arch tunnel of the NATM concept may be deteriorated. In this study, the design case of applying TBM pre-excavation type 2-arch tunnel for the first time in Korea was mainly described. The main considerations for the segment design of TBM pre-excavation type 2-arch tunnel were explained for side tunnels. Also, a stability analysis was conducted to verify the effectiveness and adequacy of the TBM pre-excavation type 2-arch tunnel.

• Tunnel and Underground Space
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• v.34 no.4
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• pp.413-420
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• 2024

When planning gripper TBM, which is highly applicable to urban areas, the excavation characteristics are not considered. In addition the excavation stability and constructability are degraded by installing reinforcements in the adjacent construction site considering the relaxation load theory of the pre-existing NATM. In this study, a rationalization plan for the support was proposed considering the excavation characteristics of gripper TBM when planning reinforcements for adjacent pre-existing construction. The effect of excavation on the surrounding ground was analyzed by conducting three-dimensional stability analyses considering the construction stage for each excavation phase. In NATM, relaxation phenomenon is concentrated in tunnel face due to non-supporting time occurring simultaneously with excavation, but gripper TBM supports the ground around the tunnel face through the cutter head and skin plate, simultaneously causing ground relaxation behind the skin plate. Considering these excavation characteristics, problems in reinforcement planning for adjacent construction at the study site were pointed out. A performance improvement plan for a reasonable supporting system was proposed.

• Tunnel and Underground Space
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• v.2 no.1
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• pp.177-189
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• 1992

As tunnel becomes longer and larger, TBM has become one of the most popular methods of excavatio in rock. This paper describes the degree of operation the degree of availability and penetration rate of TBM and TBE applied in Namsan roadway tunnelling site. Net penetration rate was 1.62m/hr for TBM and 0.72m/hr for TBE. Net penetration rate showed no direct relation to daily advance or penetration time, but the lower bound of penetration rate could be obtained from the relation with daily advance. For both of TBM and TBE, the degree of operation and the degree of availability were 33.8% and 68.6% respectively. Life time of normal cutter was $310m^3$ for TBM and $194m^3$ for TBE, while that of center and gauge cutter was about $50m^3$. When the two machines were compared, TBM showed 80% higher penetration rate, and 40% shorter life time of cutter.

• 기계와재료
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• v.21 no.4
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• pp.96-105
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• 2010

도로 및 철도는 차량의 고속화와 신속한 물류의 유통을 위해 직선 및 수평화가 절실하게 요구되며, 국내 건설구간의 약 50~70%가 산악지형으로서 터널공사가 필수적으로 요구된다. 국내터널굴착은 주로 발파에 의한 NATM(New Austrian Tunneling Method)으로 공사가 이루어지고 있으나, 굴착효율이 낮으며 안전사고의 위험성이 높다. 해외에서는 급속한 시공을 위하여 TBM(Tunnel Boring Machine)의 적용 사례가 증가하고 있다. 그러나 국내에는 TBM에 대한 연구가 전무한 상태이고, TBM 터널의 설계 시공 기술과 경험이 미흡하다. 최근 대도시의 지하터널과 장대터널의 수요가 증대되어 TBM터널시공 기술과 TBM장비의 국산화가 절실하게 요구되고 있다. 본고에서는 국내외 주요 TBM 시공현황과 전망을 정리하여 TBM 터널 기술의 확보가 매우 시급함을 상기시키고자 하였다.

• Computers and Concrete
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• v.22 no.2
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• pp.239-248
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• 2018

TBM penetration rate is a function of intact rock properties, rock mass conditions and TBM operational parameters. Machine rate of penetrationcan be predicted by knowledge of the ground conditions and its effects on machine performance. The variation of TBM operational parameters such as penetration rate and thrust plays an important role in its performance. This study presents the results of the analysis on the TBM penetration rates in schistose rock types present along the alignment of Golab tunnel based on the analysis of a TBM performance database established for every stroke through different schistose rock types. The results of the analysis are compared to the results of some empirical and theoretical predictive models such as NTH and QTBM. Additional analysis was performed to find the optimum thrust and revolution per minute values for different schistose rock types.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.3
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• pp.421-435
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• 2017

Recently, due to the saturation of ground structures and the overpopulation of pipeline facilities requires to development of underground structures as an alternative to ground structures. Thus, mechanized tunnel construction of the shield TBM method has been increasing in order to prevent vibration and noise problems in construction of the NATM tunnel for the urban infrastructure construction. Tunnel construction plan for the tunnel line should be formed in a sharp curve to avoid building foundation and underground structures and it is inevitable to develop a shield TBM technology that suits the sharp curve tunnel construction. Therefore, this study is about the structural stability technology of the articulation jack, shield jack and skin plate for the shield TBM thrust in case of the mechanized tunnel construction that is a straight and sharp curve line. The construction case study and shield TBM operation principle are examined and analyzed by the theoretical approach. The torque of the cutter head, the thrust of the articulation jack and the shield jack, the amount of over cutting for curve is important respectively in shield TBM construction of straight and sharp curve line. In addition, it is very important to secure the stability of the skin plate structure to ensure the safety of the inside worker. This study examines the general structure and construction of the equipment, experimental simulation was carried out through numerical analysis to examine the main factors and structural stability of the skin plate structure. The structural stability of the skin plate was evaluated and optimizes the shape by comparing the loads of the articulation jack by selecting the virtual soil to be applied in a straight and sharp curve line construction. Since the present structure and operation method of the shield TBM type in domestic constructions are very similar, this study will help to develop the localized shield TBM technology for the new equipment and the vulnerability and stability review.

• Magazine of korean Tunnelling and Underground Space Association
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• v.13 no.3
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• pp.39-46
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• 2011

최근 영국을 비롯한 터널기술 선진국에서는 터널 프로젝트 관련 조달(Procurement) 시스템에 대해 많은 연구 가 진행되고 있다. 조달 시스템은 오늘날 기존의 터널 공법이 발파 버럭제거 보강 공정으로 이어지는 전통적인 NATM 공법에서 TBM 기계화 시공으로 점차 변화하고 있는 가운데, TBM 장비의 설계 구매 조달 시스템은 매우 중요한 공정으로 자리 잡고 있다. 따라서 터널 프로젝트의 조달 관련, 해외 연구 상황을 파악하고 기계화 시공의 핵심 공정인 TBM 조달에 필요한 내용에 관해 알아보고자 한다.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.317-319
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• 2010

VRS는 현재 여러가지 토목공사에 이용되고 있으나 지하공사와 연계하는데는 아직 어려운 문제이다. 본 연구에서는 터널공사에 VRS를 통합하여 TBM 안내시스템을 TBM감시시스템으로 업데이트하도록 소프트웨어의 활용성을 높이고자 하였다. 여기서 개발된 TBM감시시스템은 설계경로와의 편차는 물론 여러가지 다른 측면들을 제공할 수 있을 것이다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.839-848
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• 2011

TBM (Tunnel Boring Machine) tunnel should be carry out with the adopted machine until the end of excavation because of impossibility of replacement or modification of machine. Observation of the face of the tunnel is difficult, especially in EPB(Earth Pressure Balance) shield TBM, predict changes in the ground condition with analyzing data, collected during the excavation, and it should be reflected in construction. Until recently, subjects of studies on TBM are mainly the determination of machine and the development of advance rate prediction model, according to the characteristics of ground which is the target of excavation. However, study focused on the estimation of ground conditions and the improvement in operational methods using excavation data of TBM equipment, the principal of the excavation, has been done not so much. This study examine the variances in advance rate depending on changes in operating conditions and evaluate the optimal operating conditions of adopt machine, using working data obtained from EPB shield TBM project. The result of this study is suggested as follows. First, cutter head RPM and total thrust force are biggest influences on advance rate, Second, it is recommended for proper advance rate that total thrust force is controlled while optimum cutter head RPM is kept, Third, according to the increasing trend of total thrust force, the changes in ground conditions can be predicted, the appropriate operating conditions can be determined.