• Journal of the Korean Geotechnical Society
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• v.31 no.3
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• pp.39-50
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• 2015

The installation of the expansion joints in a tunnel concrete lining and duct would minimize the cracking at the location of structural shape and stiffness change, differential settlement, big temperature change, and so on. However, it is difficult to determine the required spacing of the expansion joint in a tunnel concrete lining and duct quantitatively because the spacing is influenced by temperature change, structure construction condition, ground-structure interaction, and etc. Nevertheless, a highway specification (Korea Expressway Corporation, 2012) or a road design manual (Ministry of Land, Transport and Maritime Affairs, 2010) specifies that the expansion joint spacing in a tunnel concrete lining should be installed uniformly smaller than 25 m from the tunnel portals to 50 m inside of a tunnel and elsewhre 20-60 m in a tunnel (because there is no specifcation for a duct it is assumed that a duct follows the specfication of lining). This specification results in several construction and economic problems in relation with a tunnel construction. Accordingly, in order to minimize the problems, this study analyzed both domestic and foreign design standards and specifications. In addition, field test, theoretical and numerical analyses were carried out in relation to the expansion joint in a tunnel lining and duct. The purpose of this study is to reestabilish a criterion for installing the expansion joint in a tunnel concrete lining and duct.

• Tunnel and Underground Space
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• v.20 no.1
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• pp.58-64
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• 2010

GLI model was verified to consider the interaction between a ground and a tunnel lining and to rationally reduce the ground load acting on the secondary lining(concrete lining) of a tunnel. In this study, the economy and the construction condition of tunnel concrete linings designed by a conventional frame model at Lot O of OO line were highly enhanced through a field design change using GLI model. For a few safe considerations, not only about 50% saving of reinforcing steel could reduce the material cost but also the wide space between bars could make it easy to pour concrete mix without voids. There was large saving effect of reinforcing steel for poor ground conditions because Terzaghi's load used in the conventional frame model produces too much high loads for those conditions.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.337-349
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• 1999

There are many difficulties to the engineers in the assessment of tunnel safety. Consequently, objective assessment of concrete lining is hard even by the experts of tunnel assessment. Of several difficulties in the assessment of tunnel safety, in this study, tunnel concrete lining was focussed iud evaluated quantitatively and objectively using the Fuzzy theory which it generally considered to be appropriate for the assessment, control and judgment. T-FLAS based on fuzzy theory was developed in this study for the quantitative and objective assessment of the concrete lining in tunnels. Based on the application of T-FLAS on the evaluated field data, it was shown that the assessment system using fuzzy theory(T-FLAS) can be the effective and objective method for the assessment of concrete lining.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.3
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• pp.227-235
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• 2006

The problematic issue of cracking, water shedding in tunnel is recently coming out in the view of the structural stability. Hence, the assessment is required for the existing tunnels to achieve the structural soundness of tunnels, and their safety and maintenance. In this study, fracture behaviour and displacement of a tunnel concrete lining using steel fiber reinforcement concrete was investigated. The specimens were fabricated in single lining for a model of real road tunnel. As parameters, load condition, thickness of lining, whether or not rear cavity in crown, and a ratio of steel fiber in concrete were taken. From these factors, the load for crack and fracture, displacement, and the pattern of crack were looked into for the structural stability of a tunnel concrete lining.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.2
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• pp.121-139
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• 2023

Various tunnels such as road, subway, and railway are under construction and operation. Various types of linings are used for structural stability of tunnel structures, and concrete segment linings are mainly installed in TBM tunnel construction. In this paper, when a fire occurs in a tunnel, the impact on the concrete segment lining, which is the structure in the tunnel, and related standards, fire resistance evaluation and fire resistance method are investigated through literature review and related contents are presented. Through this, it is intended to provide an information for practitioners to secure the safety of concrete segment linings against tunnel fires.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.795-800
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• 2001

Two evaluation techniques of the tunnel lining concrete using ultra sonic velocity method are developed. Modified linear regression technique is proposed to enhance the corelation between the pulse velocity and the compressive strength of core specimens. And bivariate normal distribution is assumed to evaluate the quality of concrete as a terms of compressive strength. A simple corelation table between the pulse velocity and the compressive strength of core specimens are proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.04a
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• pp.221-226
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• 1994

A safety evaluation of cable tunnel, which is a concrete box structure with telecommunication facilities in it, exposed to fire is given. The immediate field observation was performed to find out any sign of sudden structural failure. In some region, where the fire intensity was heavy, the spalling of concrete cover in upper slab occurred. Next, more careful investigation was done with proper non-desturctive testing methods and structural analysis taking into account the changes in material properties due to fire. It seems that there is no severe damage on concrete, reinforcements and over all structural system.

• 한국터널공학회:학술대회논문집
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• 2005.04a
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• pp.270-281
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• 2005

An especial attention for old tunnel safety is required on increasing of The various tunnel recently. Specially, the lining investigation method of the old tunnel will be able to presume condition of concrete lining indirectly. Because it is many restriction thought of environment and ground condition investigation method of tunnel lining rear. This study carried out section & convergence measurement of part which was deformed in tunnel lining. It had been observed for the change of tunnel behavior with a continuous measurement. It has been analyzed for a cause of tunnel deformation and inspected for the effect after a repair-reinforcement to tunnel compared with the effect before those by structure analysis. By establishing automatic measurement system after repair-reinforcement to tunnel, it would be accomplished to convergence measurement continually. As a result, it was observed that deflection and deformation of tunnel was convergent. but it should be followed to a continuous maintenance because of unstable ground condition, cause of inner tunnel, environment. The railroad tunnel which was executed a reinforcement of the tunnel lining must investigate the close condition of reinforcement lining and concrete lining.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.485-488
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• 2008

Fire intensity in tunnel fire is very severe, which might cause the spalling on the surface of shotcrete and concrete lining exposed to the heat as well as rapidly-reducing stress due to heat transfer by steel material such as anchor embedded in tunnel which plays the critical role in securing the stability of the tunnel. In this study, a fire test to identity the heat intensity(Modifired Hydrocarbon Curve) and the fire resistance of steel materials embedded as parameters, was carried out. And the evaluation to identify the thermal damage, which was based on critical temperature range for thermal damage of steel materials determined according to the road tunnel fire resistance standard established by ITA(International Tunneling Association).

• Smart Structures and Systems
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• v.21 no.5
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• pp.583-590
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• 2018

Nowadays, many tunnels have been commissioned for several decades, which require effective inspection methods to assess their health conditions. The ambient vibration test has been widely adopted for the damage identification of concrete structures. In this study, the vibration characters of tunnel lining shells built with forepoling method was analyzed based on the analytical solutions of the Donnell-Mushtari shell theory. The broken rock, foreploing, rock-concrete contacts between rock mass and concrete lining, was represented by elastic boundaries with normal and shear stiffness. The stiffness of weak contacts has significant effects on the natural frequency of tunnel lining. Numerical simulations were also carried out to compare with the results of the analytical methods, showing that even though the low nature frequency is difficult to distinguish, the presented approach is convenient, effective and accurate to estimate the natural frequency of tunnel linings. Influences of the void, the lining thickness and the concrete type on natural frequencies were evaluated.