• Proceedings of the Korean Geotechical Society Conference
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• 1997.10a
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• pp.177-184
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• 1997

• Journal of Korean Tunnelling and Underground Space Association
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• v.3 no.2
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• pp.13-22
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• 2001

In this study, numerical analyses on cut-and-cover tunnel linings were performed using different modeling methods based on both structural and geotechnical engineering. The purpose was to find a relatively more reasonable modeling method and boundary conditions. The results of the study revealed problems associated with each modeling method and factors influencing the behavior of cut-and-cover tunnel lining. A method was proposed allowing the simulation of field condition in a more rational way. It was indicated that, under the given conditions, displacements and member forces occurring on concrete lining could be different as much as 53% depending on the type of modeling method applied; and 32% depending on the boundary conditions employed. Determination of boundary conditions properly simulating actual field conditions and verification of prediction based on instrumentation are essential for rational design and analysis.

• Journal of the Korean GEO-environmental Society
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• v.12 no.12
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• pp.13-20
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• 2011

The main objective of this paper is finding the influence factors and their degree of importance to steel liner's safety by investigating and evaluating the buckling incidents of steel tunnel liner under external water pressure. The study was based on the detailed investigation to the design conditions and incident shapes at 2m diameter waterway tunnel with a partially buckled internal steel liner and concrete backfilled lining as the raw water transmission pipe line of regional water supply project. Appropriate buckling theory capable of applying this incident points was selected by referring the existing literature and compared with the results of investigation. Also, hydrogeological characteristics of this site on buckling pressure was evaluated. The result of this study was shown that both the hydrogeological characteristics of upper geologic layers and proper tunnel construction are important factors on buckling at steel liner, and hydraulic gradient level should be decided according to the hydrogeological characteristics. This incident case analysis on steel liner of pressurized waterway tunnel was expected to provide more information for realizing the problems and improvements at each design, construction and maintenance stages.

• Magazine of korean Tunnelling and Underground Space Association
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• v.11 no.4
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• pp.58-66
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• 2009

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.549-558
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• 2021

In order to keep infrastructures such as tunnels and underground facilities safe, cracks of concrete lining in tunnel should be detected by regular inspections. Since regular inspections are accomplished through manual efforts using maintenance lift vehicles, it brings about traffic jam, exposes works to dangerous circumstances, and deteriorates consistency of crack inspection data. This study aims to provide methodology to automatically extract cracks from tunnel concrete lining images generated by the existing tunnel image acquisition system. Specifically, we train a deep learning based semantic segmentation model with open dataset, and evaluate its performance with the dataset from the existing tunnel image acquisition system. In particular, we compare the model performance in case of using all of a public dataset, subset of the public dataset which are related to tunnel surfaces, and the tunnel-related subset with negative examples. As a result, the model trained using the tunnel-related subset with negative examples reached the best performance. In the future, we expect that this research can be used for planning efficient model training strategy for crack detection.

• Geotechnical Engineering
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• v.21 no.7
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• pp.26-34
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• 2005

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.95-105
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• 2014

Reinforced concrete (RC) shield tunnel lining must be designed for fireproof performance because the lining is sometimes exposed to very high temperature due to traffic accidents. Both experimental and numerical studies are carried out to evaluate fire resistance performance of precast RC tunnel lining systems. In the experimental studies, six full-scale precast RC tunnel segments are exposed to fire in order to examine the influence of various parameters on the fire resistance performance of precast RC tunnel lining. We used the temperature curve of the RABT criteria, which are severe conditions of fire temperatures. The fire test showed that the explosive spalling was not observed by substituting concrete to PP fiber reinforced concrete. A transient heat flow analysis was carried out in consideration of the material properties that change with temperature, and the results showed good agreement with the test results.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.905-913
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• 2017

To design segment lining, loads such as self weight, vertical load, horizontal load, ground reaction, water pressure, backfill grouting pressure et al. have to be considered. Earth pressure and water pressure are the major factor to design segment lining such as concrete strength, segment thickness and amount of rebar et al. To analysis earth pressure and water pressure acting on segment lining, filed monitoring and back analysis are performed in this study.

• Journal of the Korean Geotechnical Society
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• v.27 no.7
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• pp.35-45
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• 2011

Cost effective design and construction are necessary to establish the design concept of tunnel lining. Loosening load acting on the concrete lining is compared with Terzaghi tunnel theory and numerical analysis. It is analyzed under the condition of weathered rock and soil with varying in-situ stress ratio ($K_0$). Based on the result, loosening load calculated by Tcrzaghi tunnel theory is much greater than numerical analysis results. And the load calculated in weathered soil is lager than weathered rock condition. As in-situ stress ratio increases, the stress acting on the tunnel lining decreases in Terzaghi theory rapidly, whereas there is little effect in numerical analysis.

• Journal of Korean Tunnelling and Underground Space Association
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• v.6 no.1
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• pp.61-70
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• 2004

Precast Concrete Lining (PCL) is invented in order to resolve the problem of the cast-in-place concrete lining in Norway, However PCL could not consider the effect of earthquake because an earthquake rarely occurs in the region of Northern Europe, Consequently, the analysis of the effect of earthquake on PCL should be made before introducing PCL to Korea. The purpose of this research is to evaluate the stability of tunnel applying PCL in the case of earthquake. To evaluate the seismic performance of PCL, we used shaking table apparatus by 1/5 scale down model. The result of this research is as shows that deep tunnells satisfied for Korea seismic design criteria.