• 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.19 no.6
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• pp.973-984
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• 2017

There is a growing need to apply TBM tunnelling method for the construction of underground facilities such as subways and utility tunnels in urban areas. Due to the variability and uncertainty of the ground, tunnelling in urban areas has various safety hazards which could cause damage to people and properties and it is very costly to recover from accidents. Therefore, it is very important to identify hazards from the planning and design phase and to establish risk mitigation measures. In this study, a total of 31 hazards affecting the stability of TBM tunnelling works in urban areas were listed from both the technical literature and correspondence with experts in tunnelling area. The importance and priorities of the hazards were analyzed by conducting Delphi technique, which is a decision-making method by consensus among experts. Finally, 12 hazards that satisfy the content validity criteria were settled and could be used as major control factors for accident prevention during TBM tunnelling works.

• Journal of the Korea Construction Safety Engineering Association
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• s.45
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• pp.60-70
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• 2008

Mechanized tunnelling by TBMs has been extensively adopted for last two decades. Nevertheless, only few case histories have been reported. Unlike NATM tunnels, the case histories of the weak zone have been seldom reported for the mechanized tunnelling, even in the other countries. In this study, a collapse of TBM tunnel occurred in the severely altered weak rock zones between volcaniclastic rocks and granitic rocks was briefly described. A systematic geotechnical investigation, which was performed to examine the cause of the collapse, was carried out at the site and then characteristics of the rocks in the zones were evaluated. Moreover, This study propose a guide line of estimateing the possibility of collapse in TBM tunnels through comparing experimental results with surveying results of general rocks.

• Tunnel and Underground Space
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• v.28 no.1
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• pp.1-24
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• 2018

The use of TBM (tunnel boring machine) gradually increases in worldwide tunneling projects. TBM machine are often applied to more difficult and complex geological conditions in urban area, and many problems and difficulties have been reported due to these geological conditions. However, in Korea, there is a lack of research on difficult grounds so far. This paper discussed general aspects of investigation method, and problems of TBM tunneling in difficult grounds. Construction cases that passed through the difficult grounds in worldwide were analyzed and the typical difficult grounds were classified into 11 cases. For each case, the definition and general problems were summarized. Particularly, for mixed ground and boulder ground, and fault zone, which are frequent geological conditions in urban area with shallow depth, classification system, investigation methods and major considerations were discussed, and proposed the direction of future research. This paper is a basic study for the development of TBM construction technology in difficult ground, and it is expected that it will be useful for related research and construction of TBM in difficult ground in the future.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.460-468
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• 2021

A TBM is an equipment that excavates a tunnel with a full face by rotating a circular cutter head and its advantages are fast excavation rate and safe construction. A TBM, which is primarily used for tunnel excavation on civil construction sites, is easily adaptable to information and communication technology. Research related to unmanned and automated technology is being actively pursued. TBM applications for mining and energy resource development in other countries were investigated in this study. The difference of TBM applications between the mining and energy resource development and civil construction sites was examined. Technical factors such as geological conditions, depth, site access, TBM launching, alignment and inclination, TBM size, and others that should be considered when choosing a TBM were investigated. Finally, the advantages and disadvantages of TBM application in mines and the technical requirements for TBM for successful mine application are summarized.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.5
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• pp.553-561
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• 2015

In this study, the performance assessment criterion for reasonable maintenance of shield TBM tunnel was presented. The performance assessment items such as crack, leakage, breakage, spalling, exfoliation/detachment, efflorescence, quality condition, exposure of steel, carbonation, faulting step, bolts condition, drainage condition, ground condition, contact section condition and conduit condition were selected by analyzing domestic and foreign performance assessment criterions and investigating segment lining deterioration cases through the site investigation and in-depth inspection analysis result on the shield TBM tunnel. In addition, the reasonable weight using AHP (Analytic Hierarchy Process) were estimated.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.6
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• pp.599-614
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• 2014

When tunnelling with TBM (Tunnel Boring Machine), accessibility to tunnel face is very limited because tunnel face is mostly occupied by a bunch of machines. Existing techniques that can predict ground condition ahead of TBM tunnel are extremely limited. In this study, the TBM Resistivity Prediction (TRP) system has been developed for predicting anomalous zone ahead of tunnel face utilizing electrical resistivity. The applicability and prediction accuracy of the developed system has been verified by performing field tests at subway tunnel construction site in which an EPB (Earth Pressure Balanced) shield TBM was used for tunnelling work. The TRP system is able to predicts the location, thickness and electrical properties of anomalous zone by performing inverse analysis using measured resistivity of the ground. To make field tests possible, an apparatus was devised to attach electrode to tunnel face through the chamber. The electrode can be advanced from the chamber to the tunnel face to fully touch the ground in front of the tunnel face. In the 1st field test, none of the anomalous zone was predicted, because the rock around the tunnel face has the same resistivity and permittivity with the rock ahead of tunnel face. In the 2nd field test, 5 m thick anomalous zone was predicted with lower permittivity than that of the rock around the tunnel face. The test results match well with the ground condition predicted, respectively, from geophysical exploration, or directly obtained either from drilling boreholes or from daily observed muck condition.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.1
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• pp.47-58
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• 2020

The interest in the use of shield TBM (Tunnel Boring Machine) on the tunnel excavation has been increased rapidly in Korea. The shield TBM tunnel is generally designed as non-drainage tunnel. Consequently, if water leakage through the segment joints happens, big problems on the usage and stability of tunnel can be occurred. In this study, the variation of waterproof capacity of hydrophilic rubber waterstop by the construction error and excessive displacement of segment was studied. In particular, the waterproof capacity of each of single and double layer arrangements of hydrophilic rubber waterstop was examined to verify the efficiency of the double layer arrangement. The test results show that the single layer and double layer hydrophilic rubber waterstop showed the same waterproof performance. hydrophilic rubber waterstop has favorable on the offset, however unfavorable on the gap.

• Magazine of korean Tunnelling and Underground Space Association
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• v.16 no.5
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• pp.51-55
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• 2014

• Geotechnical Engineering
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• v.39 no.3
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• pp.28-55
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• 2023