• 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.

• 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.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.4
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• pp.403-415
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• 2014

Recently, the temperature rise in the summer due to climate change, power usage is increasing rapidly. As a result, power generation facilities have been newly completed and the need for ultra-high-voltage transmission line for power transmission of electricity to the urban area has increased. The mechanized tunnelling method using a shield TBM have an advantage that it can minimize vibrations transmitted to the ground and ground subsidence as compared with the conventional tunnelling method. Despite the popularity of shield TBM for cable tunnel construction, study on the mechanical behavior of cable tunnel driven by shield TBM is insufficient. Thus, in this study, the effect of fractured zone ahead of tunnel face on the mechanical behavior of the shield TBM cable tunnel is investigated. In addition, it is intended to compare the behavior characteristics of the fractured zone with continuous model and applying the interface elements. Tunnelling with shield TBM is simulated using 3D FEM. According to the change of the direction and magnitude of the fractured zone, Sectional forces such as axial force, shear force and bending moment are monitored and vertical displacement at the ground surface is measured. Based on the stability analysis with the results obtained from the numerical analysis, it is possible to predict fractured zone ahead of the shield TBM and ensure the stability of the tunnel structure.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.637-658
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• 2022

TBM tunnel is simple with the iterative process of excavating the ground, building a segment ring-build, and backfilling. Drill & Blast, a conventional tunnel construction method, is more complicated than the TBM tunnel and has some restrictions because it repeats the inspection, drilling, charging, blasting, ventilation, muck treatment, and installation of support materials. However, the preparation work for excavation requires time and cost based on a very detailed plan compared to Drill & Blasting, which reinforces the ground and forms a tunnel after the formation of tunnel portal. This is because the TBM equipment for excavating the target ground determines the success or failure of the construction. If the TBM, an expensive order-made equipment, is incorrectly configured at the assembly stage, it becomes difficult to excavate from the initial stage as well as the main excavation stage. When the assembled shield TBM equipment is dismantled again, and a situation of re-assembly occurs, it is difficult throughout the construction period due to economic loss as well as time. Therefore, in this study, the layout and plan of the site and the assembly process for each major part of the TBM equipment were reviewed for the assembly of slurry shield TBM to construct the largest diameter road tunnel in domestic passing through the Han River and minimized interference with other processes and the efficiency of cutter head assembly and transport were analyzed and improved to suit the site conditions.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.1
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• pp.79-94
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• 2022

The demand for tunnel construction is increasing as part of underground space development due to urban saturation. The shield TBM method minimizes vibration and noise and minimizes ground deformation that occurs simultaneously with excavation, and shield TBM is generally applied to tunnel construction in urban areas. The importance of urban ground settlement prediction is increasing day by day, and in the case of shield TBM construction, ground deformation is minimized, but ground settlement due to tunnel excavation inevitably occurs. Therefore, in this study, the correlation between shield TBM, which is highly applicable to urban areas, and ground settlement is analyzed to suggest the shield TBM construction factors that have a major effect on ground settlement. Correlation analysis was performed between the shield TBM construction data and ground settlement measurement data collected at the actual site, and the degree of correlation was expressed as a correlation coefficient "r". As a result, the main construction factors of shield TBM affecting ground settlement were thrust force, torque, chamber pressure, backfill pressure and muck discharge. Based on the results of this study, it is expected to contribute to the presentation of judgment criteria for major construction data so that the ground settlement can be predicted and controlled in advance when operating the shield TBM in the future.

• Magazine of korean Tunnelling and Underground Space Association
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• v.7 no.1
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• pp.32-39
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• 2005

• Magazine of korean Tunnelling and Underground Space Association
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• v.11 no.2
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• pp.34-46
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• 2009

• Journal of the Korea Construction Safety Engineering Association
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• s.21
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• pp.39-49
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• 1996

• Magazine of korean Tunnelling and Underground Space Association
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• v.26 no.1
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• pp.46-62
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• 2024

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.09a
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• pp.59-79
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• 2006

The successful execution of shield tunnelling depends on the cutting ability of cutter. So the selection of shape, size and material of cutter according to geology condition is important work. Since shield tunnelling method was first invented in 1881, the cutting tool for rock has been developed owing to various experiments and researches, the study for soil, however, is insufficient. This paper introduces the shield tunnelling that will be carried out on weathered rock section (920m) of Seoul Subway Line 7 Extension C703. The shape and the material of cutter are discussed required for execution without replacement of cutter tool as well as for advance of excavation efficiency. In addition the estimation method of cutter abrasion in case of excavation on weathered soil is proposed and verified. Specially, the coefficient of abrasion for different soil and cutter is proposed by means of investigation into construction example of foreign country.