• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.89-96
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• 2001

A concrete lining of NATM tunnel is the final product of a process that involves planning and evaluation of user needs, geotechnical investigations, analysis of ground-lining interaction, construction, and observations and modifications during construction. The designer must consider the lining in context of the many function, construction, and geotechnical requirements. Also, the loss of supporting capacity of shotcrete lining due to poor rock qualities and shotcrete erosion must be considered. The values, shapes, and estimating methods of rock load and water pressure are very different with every designers. Estimating methods of rock loads used in the design of NATM tunnel concrete lining are investigated. Numerical analyses are done in various conditions. And the rock loads estimated from radial stress and plastic zone are compared respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.153-160
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• 1999

It has been recognized that the assessment of concrete lining is very uncertain and subjective depending on the engineers who are in charge. T-FLAS which was 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.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.541-544
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• 2008

Generally numerical analysis of tunnel lining, under dynamic loading condition, performed not considering pore pressure. But if tunnel excavated under the surface of water, such as bottom of the sea, the river bed, tunnel lining can take pore water pressure. It may be different from evaluated numerical analysis not considering pore pressure. Therefore tunnel design should consider effect of water pressure acting on tunnel lining.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.4
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• pp.365-375
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• 2006

The structural analysis for the secondary lining of tunnels is generally performed by a frame analysis model. This model requires a ground loosening load estimated by some empirical methods, but the load is likely to be subjective and too large. The ground load acting on the secondary lining is due to the loss of the supporting function of the first support members such as shotcrete and rockbolts. Therefore, the equilibrium condition of the ground and the first support members should be considered to estimate the ground load acting on the secondary lining. Ground-lining interaction model, shortly GLI model, is developed on the basis of the concept that the secondary lining supports the ground deformation triggered by the loss of the support capacity of the first support members. Accordingly, the GLI model can take into account the ground load reflecting effectively not only the complex ground conditions but the installed conditions of the first support members. The load acting on the secondary lining besides the ground load includes the groundwater pressure and earthquake load. For the structural reinforcement of the secondary lining based on the ultimate strength design method, the factored load and various load combination should be considered. Since the GLI model has difficulty in dealing with the factored load, introduced in this study is the superposition principle in which the section moment and force of the secondary lining estimated for individual loads are multiplied by the load factors. Finally, the design method of the secondary lining using the GLI model is applied to the case of a shallow subway tunnel.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.621-628
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• 2005

The concrete lining in tunnel performs structural and nonstructural functions. The concrete lining works as a structural member for released load and residual water pressure in NATM tunnel system. Also concrete lining used for finishing the tunnel surface. The initial crack of concrete lining is reported because of difficulties in construction process, which concrete is injected into 30$\sim$40cm narrow gap between lining form and tunnel surface through 500${\times}$600mm small injection holes in the form. In this paper, we research a reason of initial crack occurrence by the case study of 4 lane wide span tunnel, and propose an improved method for crack minimization in construction process. We verify that the proposed method can give qualified concrete lining by carrying out the concrete injection model test and the numerical analysis of concrete flow.

• International Journal of Concrete Structures and Materials
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• v.2 no.2
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• pp.145-152
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• 2008

So far, there has been no study of the concrete to strengthen in the lining of the tunnels, except for the study of the stability of subgrade and the tunnel construction technologies. In the existing concrete work for tunnel lining, lots of problems happen due to the partial compaction and the material segregation after casting concrete. Accordingly, the aim of this study is to improve economic efficiency and secure durability through the improvement of the construction performance and quality of the concrete for the tunnel lining among the civil structures. Therefore, the compactability and strength properties of the High Flowing Self-Compacting Lining Concrete (HSLC) are evaluated to develop the mixing proportion for design construction technology of HSLC that can overcome the inner cavity due to the reduced flowability and unfilled packing, which has been reported as the problem in the existing lining concrete. The result of the evaluation shows that the ternary mix meets the regulations better than the binary mix. Consequently, it has been judged applicable to the cement for tunnel lining.

• 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.

• Computers and Concrete
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• v.21 no.4
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• pp.399-406
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• 2018

The present study focuses on the performance of basalt fiber reinforced concrete (BFRC) lining in tunnel situated in sandstone rock when subjected to internal blast loading. The blast analysis of the lined tunnel is carried out using the three-dimensional (3-D) nonlinear finite element (FE) method. The stress-strain response of the sandstone rock is simulated using a crushable plasticity model which can simulate the brittle behavior of rock and that of BFRC lining is analyzed using a damaged plasticity model for concrete capturing damage response. The strain rate dependent material properties of BFRC are collected from the literature and that of rock are taken from the authors' previous work using split Hopkinson pressure bar (SHPB). The constitutive model performance is validated through the FE simulation of SHPB test and the comparison of simulation results with the experimental data. Further, blast loading in the tunnel is simulated for 10 kg and 50 kg Trinitrotoluene (TNT) charge weights using the equivalent pressure-time curves obtained through hydrocode simulations. The analysis results are studied for the stress and displacement response of rock and tunnel lining. Blast performance of BFRC lining is compared with that of plain concrete (PC) and steel fiber reinforced concrete (SFRC) lining materials. It is observed that the BFRC lining exhibits almost 65% lesser displacement as compared to PC and 30% lesser displacement as compared to SFRC tunnel linings.

• Journal of the Korean Society of Clothing and Textiles
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• v.8 no.1
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• pp.1-11
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• 1984

An attempt was made to determine individual thermal resistances of 2-lining fabrics ad 4-outer fabrics for Korean-styled clothes, and 4-lining fabrics ad 5-outer fabrics for Western-styled clothes at $19^{\circ}C$ and $24^{\circ}C$. The thermal insulation effects for different lining fabrics in Korean and Western-styled clothes were deduced in determining heart rate, rectal temperature, mean skin temperature and microclimates of subjects. The subjects were dressed experimental clothing which were made of lining and outer fabrics in question, and seated in an environmental chamber during the experiment. 1. Thermal resistances of lining fabrics : For Korean-styled clothes. nylon sheer is larger than unzosa. For Western-styled clothes, rayon, acetate, nylon(taffeta) and kalkali in that order. 2. Thermal resistances of lining fabrics combined : with outer fabrics: For Korean-styled clothes. the measured value is larger than the one of simple aggregate value. But in the case of Western-styled clothes, the measured value is smaller than simple aggregate value. 3. The effects of lining on the thermal insulation of the whole clothing: In case when subjects wore unlimited number of underwear, no matter what lining fabrics were used in Korean and Western-styled clothes less thermal insulation effects were indicated. For the case, however, if subjects wore only limited underwear, there are significant differences of thermal insulation between experimental clothings.

• Structural Engineering and Mechanics
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• v.71 no.6
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• pp.699-712
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• 2019

The reinforced concrete lining of hydraulic pressure tunnels tends to crack under high inner water pressure (IWP), which results in the inner water exosmosis along cracks and involves typical hydro-mechanical interaction. This study aims at the development, validation and application of an indirect-coupled method to simulate the lining cracking process. Based on the concrete damage plasticity (CDP) model, the utility routine GETVRM and the user subroutine USDFLD in the finite element code ABAQUS is employed to calculate and adjust the secondary hydraulic conductivity according to the material damage and the plastic volume strain. The friction-contact method (FCM) is introduced to track the lining-rock interface behavior. Compared with the traditional node-shared method (NSM) model, the FCM model is more feasible to simulate the lining cracking process. The number of cracks and the reinforcement stress can be significantly reduced, which matches well with the observed results in engineering practices. Moreover, the damage evolution of reinforced concrete lining can be effectively slowed down. This numerical method provides an insight into the cracking process of reinforced concrete lining in hydraulic pressure tunnels.