• Magazine of korean Tunnelling and Underground Space Association
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• v.23 no.2
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• pp.63-78
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• 2021

• Magazine of korean Tunnelling and Underground Space Association
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• v.23 no.1
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• pp.26-43
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• 2021

• Magazine of korean Tunnelling and Underground Space Association
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• v.24 no.3
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• pp.28-47
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• 2022

• Magazine of korean Tunnelling and Underground Space Association
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• v.26 no.1
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• pp.21-45
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• 2024

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.2
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• pp.199-207
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• 2003

Tunnel modelling in the field of geotechnical engineering essentially requires models of tunnelling machines and the simulation of tunnelling processes to clarify the detailed behaviour of tunnel construction. Modern advanced mechatronics, including construction processes, machinining and control technologies, are making it possible to fabricate such models. These technologies, however, are essentially developed in a gravity field condition and are needed to examine in a 1g or cenrifuge field condition. This paper presents the simulation method for tunnelling processes and the design method for tunnelling machines with special reference to the problem of earth pressure acting on the lining of a shield tunnel. The paper then introduces and verifies the design method for tunnelling machines in the 1g field by means of checking the reproduceability of experiment data and their comparison with data in the field.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.6
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• pp.725-744
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• 2022

As the construction of infrastructure using the underground tunnel in urban area have been rapidly increased, various accidents and collapses of tunnel including structure have been occurred in deep urban tunnelling. The concern and worry relating to the risk and safety of the tunnel during excavation is becoming the key issues in deep urban tunnelling. In this study, it was conducted for deep urban tunnel at GTX (Great Train Express) line which was located in Seoul metropolitan area to determine the risk characteristics for tunnel according to urban tunnelling. Also, it was reviewed the risk analysis and evaluation of the tunnel, shaft and station. And after a review of risk analysis and evaluation for risk register and hazard identification by using a risk matrix method, safety management of the tunnel according to excavation was evaluated to be secured. This study is expected to be applied as useful approach in deep urban tunnelling if you need to review the risk and safety management system of tunnel according to mitigation measures in complex urban tunnelling.

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.2
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• pp.91-105
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• 2015

In the current work, a series of three-dimensional (3D) finite element analyses have been performed to study the effects of the locations of pile tips on the behaviour of single piles to adjacent tunnelling. In the numerical modelling, several key issues, such as tunnelling-induced pile head settlements, axial pile forces, interface shear stresses and apparent factors of safety have been studied. When the pile tips are inside the influence zone which considers the relative pile tip location with respect to the tunnel position, tunnelling-induced pile head settlements are larger than those computed from the greenfield condition. However, when the pile tips were outside the influence zone, an opposite trend was observed. When the pile tips were inside the influence zone, tunnelling-induced tensile pile forces developed; however, when the pile tips were outside the influence zone, tunnelling-induced compressive pile forces were mobilised, associated with larger settlements of the surrounding soil than the pile settlements. It has been shown that the increases in the tunnelling-induced pile head settlements have resulted in reductions of the apparent factor of safety by about 50% when the pile tips are inside the influence zone, therefore severly affecting the serviceability of piles. The pile behaviour, when considering the location of pile tips with regards to the influence zone, has been analysed in great detail by taking the tunnelling-induced pile head settlements, axial pile force and apparent factor of safety into account.

• Journal of the Korean GEO-environmental Society
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• v.16 no.6
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• pp.13-22
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• 2015

In the current work, a series of three-dimensional (3D) numerical modelling has been performed in order to study the effects of the relative locations of tunnels with respect to the position of pile tips which governs the behaviour of pre-existing, adjacent single piles. In the numerical analyses, several governing factors, such as tunnelling-induced pile head settlements, relative displacements, volume losses, axial pile forces, interface shear stresses and apparent factors of safety have been analysed. When the pile tips are inside the tunnelling influence zone, of which the pile tip location is considered with respect to the tunnel position, tunnelling-induced pile head settlements are larger than the ground surface settlements, resulting in tunnelling-induced tensile pile forces. On the contrary, when the pile tips are outside the influence zone, compressive pile forces associated with downward shear stresses at the upper part of the piles are developed. Based on computed load and displacement relation of the pile, the apparent factors of safety of the piles inside the tunnelling influence zone have been reduced by 36% in average. The shear transfer mechanism based on the relative tunnel locations has been analysed in great detail by considering tunnelling-induced pile forces, interface shear stresses and the apparent factors of safety.

• Magazine of korean Tunnelling and Underground Space Association
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• v.21 no.2
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• pp.117-129
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• 2019

Tunnelling in urban environments is very common nowadays as large cities are expanding and transportation demands require the use of the underground space for creating extra capacity. Inevitably, any such new construction may have significant effects on existing nearby infrastructure and therefore relevant assessment of structural integrity and soil-structure interaction is required. Foundation piles can be rather sensitive to nearby tunnel construction and therefore their response needs to be evaluated carefully. Although detailed three-dimensional continuum finite element analysis can provide a wealth of information about this behaviour of piles, such analyses are generally very computationally demanding and may require a number of material and other model parameters to be properly calibrated. Therefore, relevant simplified approaches are used to provide a practical way for such an assessment. This paper presents a simple method where the pile is modelled with beam finite elements, pile-soil interaction is modelled with soil springs and tunnelling-induced displacements are introduced as an input boundary condition at the end of the soil springs. The performance of this approach is assessed through some examples of applications.

• Magazine of korean Tunnelling and Underground Space Association
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• v.14 no.5
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• pp.44-60
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• 2012