• Title, Summary, Keyword: 쉴드 TBM

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Application technique on thrust jacking pressure of shield TBM in the sharp curved tunnel alignment by model tests (축소모형실험을 통한 급곡선 터널에서의 Shield TBM 추진 압력 적용 기술에 대한 연구)

  • Kang, Si-on;Kim, Hyeob;Kim, Yong-Min;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.2
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    • pp.335-353
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    • 2017
  • This paper presents the application technique on thrust jacking pressuring of shield TBM in the sharp curved tunnel alignment by model tests. Recently, the application of shield TBM method as mechanized tunnelling is increasing to prevent the vibration and noise problems, which can be occurred in the NATM in the urban area in Korea. However, it is necessary to plan the sharp curved tunnel alignment in order to avoid the building foundation and underground structures, to develop the shield TBM operation technique in the shape curved tunnel alignment. Therefore, the main operation parameters of shield TBM in the curved tunnel alignment are reviewed and analyzed based on the case study and analytical study. The results show that the operation of shield jacking force system is the most important technique in the shape curved tunnel alignment. The simplified scaled model tests are also carried out in order to examine the ground-shield TBM head behaviour. The earth pressures acting on the head of shield TBM are investigated according to two different shield jacking force systems (uniform and un-uniform pressure) and several articulation angles. The results obtained from the model tests are analysed. These results will be very useful to understand the shield TBM head interaction behaviour due to the shield jacking operation technique in the shape curved tunnel alignment, and to develop the operation technique.

Analysis on the behavior of shield TBM cable tunnel: The effect of the distance of backfill grout injection from the end of skin plate (뒷채움 주입 거리에 따른 전력구 쉴드 TBM 터널의 거동 특성 분석)

  • Cho, Won-Sub;Song, Ki-Il;Ryu, Hee-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.16 no.2
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    • pp.213-224
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    • 2014
  • Recently, tunnelling with TBM is getting popular for the construction of cable tunnel in urban area. Mechanized tunnelling method using shield TBM has various advantages such as minimization of ground settlement and prevention of vibration induced by blasting that should be accompanied by conventional tunnelling. In Korea, earth pressure balance (EPB) type shield TBM has been mainly used. Despite the popularity of EPB shield TBM for cable tunnel construction, study on the mechanical behavior of cable tunnel driven by shield TBM is insufficient. Especially, the effect of backfill grout injection on the behavior of cable tunnel driven by shield TBM is investigated in this study. Tunnelling with shield TBM is simulated using 3D FEM. The distance of backfill grout injection from the end of shield skin varies. Sectional forces such as axial force, shear force and bending moment are monitored. Vertical displacement at the ground surface is measured. Futhermore, the relation between volume loss and the distance of backfill grout injection from the end of skin plate is derived. Based on the stability analysis with the results obtained from the numerical analysis, the most appropriate injection distance can be obtained.

Development of simulation equipment system on EPB shield TBM hood operation (토압식 쉴드TBM의 후드부 시뮬레이션 장비 시스템 개발에 대한 연구)

  • Kim, Sang-Hwan;Oh, Tae-Sang;Park, Soo-Hwan;Lee, Choong-Yeoul;Park, Jong-Kwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.16 no.2
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    • pp.193-201
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    • 2014
  • This paper presents the development of simulation system on EPB shield TBM Hood operation. In recent, EPB shield TBM is widely used in the tunnel construction. Since the hood system of the EPB shield TBM is most important to excavate the tunnel, it is necessary to perform the simulation of hood system to investigate the design and operation parameters prior to tunnel construction. In order to carry out this study, the scaled simulation system was designed and developed. The model tests were performed to verify the developed system. During the simulation, the earth pressures developed in the chamber during tunnelling were measured to evaluate the operation technique. The test results obtained by the developed simulation system show clearly the similar behaviour of TBM hood compared with the field data. It was also found that the ground loss during tunnelling is dependent on the change of earth pressure in chamber. Therefore, the simulation system developed in this study will be very useful to evaluate the operation technique of the TBM hood prior to tunnel construction. In addition, this system will be applied in a various condition of ground to get the operating information.

A study on the risk and settlement evaluation of a shield TBM excavated in soft marine sedimentary soils (해저 연약 퇴적층 지반 쉴드 TBM 위험요인 평가 및 장비 침하에 관한 연구)

  • You, Kwang-Ho;Park, Chi-Myeon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.18 no.4
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    • pp.355-364
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    • 2016
  • Recently, a 3,250 meter-long tunnel was constructed beneath the sea bed formed of composite sedimentary soils to transport reusable waste heat gas of industrial complex in the west coast of Korea. Some risks such as machine settlement always exist due to the uncertainties of geological and construction factors during the subsea shield TBM tunnelling. In this construction site, the deviation of tunnel alignment caused by shield TBM settlement was occurred during excavation. It was examined that the lack of bearing capacity of soft clay was a main cause. This paper evaluates the risk of shield TBM tunnelling considering the ground conditions. Correlation between machine settlement and its advance rate was evaluated through the analytical equation in which bearing capacity is considered and a 3-D numerical analysis which can simulate the TBM advance condition (in other words, the dynamic condition). It was found out that a shield TBM could settle due to the insufficient bearing capacity of soft clay layers. In order to prevent such the problem, the best advance rate proper to the ground characteristics is needed to be applied. In the ground conditions of the section of interest, it was turned out that if the shield TBM advance rate was maintained between 35 mm/min and 40 mm/min, the machine settlement could be avoided.

A Study of Shield TBM Tunnelling-induced Volume Loss Estimation Considering Shield Machine Configurations and Driving Data (쉴드 TBM의 장비 형상 및 굴진 데이터를 고려한 체적손실 산정 연구)

  • Park, Hyunku;Chang, Seokbue;Lee, Seungbok
    • Tunnel and Underground Space
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    • v.25 no.5
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    • pp.397-407
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    • 2015
  • Estimation of shield TBM tunnelling-induced volume loss is of great importance for ground settlement control. This study proposed a simple method for evaluation of volume loss during TBM tunnlling, which is able to take into account of shield machine configurations and main driving data in calculation. The method was applied to analyze the tunnelling cases with earth pressure balanced and slurry pressure balanced shiled TBM, and mostly, reasonable agreements with monitoring results were found. Additional discussions were made for some disagreements.

A study on the face pressure control and slurry leakage possibility using shield TBM model test (축소 모형실험을 통한 토피조건별 이수압식 쉴드 TBM의 챔버압 및 이수분출 가능성 평가)

  • Koh, Sungyil;Shin, Hyunkang;La, You-Sung;Jung, Hyuksang
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.22 no.3
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    • pp.277-291
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    • 2020
  • Shield TBM is a tunnelling method that has a wider range of applications in the poor ground condition compared to conventional tunnels (Drill and Blast). Currently, a 13.3 m large-diameter slurry shield TBM is preparing for construction to pass under the Han River. Shield TBM is divided into slurry and EPB shield TBM, and management items during construction are different depending on each characteristic. In this paper, the equipment type, origin, application case and trouble case were analyzed for slurry shield TBM, which is mainly constructed in soft ground. In addition, 2D and 3D model tests were conducted on the condition of soil depth for the possibility of slurry leakage into front of the equipment, with appropriate chamber pressure. Based on this paper, it proposed to provide basic and reference data for proper excavation surface pressure and chamber pressure during construction of slurry shield TBM under soft ground conditions, and proposed measures to minimize stability and environmental decline due to slurry ejection.

Simulation of shield TBM tunneling in soft ground by laboratory model test (실내모형시험을 통한 연약지반의 쉴드 TBM 터널굴착 모사)

  • Han, Myeong-Sik;Kim, Young-Joon;Shin, Il-Jae;Lee, Yong-Joo;Shin, Yong-Suk;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.5
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    • pp.483-496
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    • 2013
  • This paper presents the shield TBM technology in soft ground tunnelling. In order to perform this study, a scale model test was carried out using the developed small scaled shield TBM machine. The various instrumentations were conducted during the simulation of tunnelling. In addition, the ground behavior due to the shield TBM operation parameters was measured during the simulation. Based on the simulation results, the stability of the ground was evaluated and the fundamental shield TBM tunnelling technique in the soft ground was suggested. In conclusion, design's reliability through laboratory small scale model test about Shield-TBM section was obtained, and both the improvement plan for safety during construction and the construction plan for securing airport runway's safety during tunnel passing by Shield-TBM propulsion were suggested.

An Experimental Study on Shield TBM Tunnel Face Stability in Soft Ground (연약지반에서의 쉴드 TBM 굴착시 막장면 안정성 평가를 위한 실험적 연구)

  • Kim, Yong-Man;Lee, Sang-Duk;Choo, Seok-Yeon;Koh, Sung-Yil
    • Journal of the Korean Society for Railway
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    • v.16 no.1
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    • pp.47-51
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    • 2013
  • In this study, we carried out an experimental shield TBM excavation model test using a down-scale device in soft clay, to understand tunnel-face stability properties in relation to changes in slurry pressure. We performed five tests according to tunnel depth (0.5D, 0.75D, 1.0D, 1.25D, 1.5D), and compared theoretical tunnel-face pressure with model test results. The range in theoretical tunnel-face slurry pressure ($P_{min}{\leq}P_{slurry\;pressure}{\leq}P_{max}$), which is determined by earth pressure and water level, was very similar to the model test result. This result was due to the more isotropic condition of the soft clay ground, than of rocky ground.

Study on the structure of the articulation jack and skin plate of the sharp curve section shield TBM in numerical analysis (수치해석을 통한 급곡선 구간 Shield TBM의 중절잭 및 스킨플레이트 구조에 관한 연구)

  • Kang, Sin-Hyun;Kim, Dong-Ho;Kim, Hun-Tae;Song, Seung-Woo
    • 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.

A study on the damage of cutter bit due to the rotation speed of shield TBM cutter head in mixed ground (복합지반에서의 쉴드 TBM 커터헤드의 회전속도에 따른 커터비트 손상에 관한 실험적 연구)

  • Kang, Eun-Mo;Kim, Yong-Min;Hwang, In-Jun;Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.3
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    • pp.403-413
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    • 2015
  • This paper presents the cutter bit damage due to the rotation speed of shield TBM cutter head in the mixed ground. The efficient of cutter bits and disk cutter are very important for tunnelling in mixed ground. In particular, this research is focused on the performance of cutter bits during excavation in mixed ground which is consist of the weathered soil and rock formation. In order to carry out this research, the experimental works are prepared performed by using the scaled shield TBM cutter bits evaluation machine developed. The mixed ground is prepared considering with a scale effect of tunnel size. Three different rotation speeds of shield TBM cutter head (i.e. 2, 3, 4 rpm) are applied in the experimental work. The drag forces acting on the cutter bits are measured at each cutter bit during rotation of cutter head. It is also analysed the variation of drag forces due to the rotation speed of shield TBM cutter head. The results of this research are clearly shown that the drag forces acting on the cutter bits are jumped up at the boundary between weathered soil and rock. It is also indicated that the jamping drag forces are increased with increasing the rotation speed of the cutter head. It is found from the research that the higher rotation speed of shield TBM cutter head will be high risk in the mixed ground. It is, therefore, suggested that the use of lower rotation speed of shield TBM cutter head is recommended for reducing the cutter bit damage in practice.