• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.4
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• pp.437-447
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• 2009

It is easily found by several references of NATM that the cracks on the lining concrete of NATM are more developed than those of the conventional tunnel methods. Based on the results of research, the new method is proposed to control and protect the axial cracks on the tunnel linings. Also, the efficiency of proposed method is evaluated using the Distinct Element Method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.25-34
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• 2017

Since the 30-year-old facility is expected to surge from 10.5% to 23.9% in 10 years, the new evaluation system is needed to establish efficient maintenance system for securing the safety and extending the life span of existing facilities. In this study, Delphi and AHP(Analytic Hierarchy Process) was conducted to provide a systematic new evaluation system for the NATM tunnel, which is the most frequently constructed structure of the existing tunnel. Since the existing assessment systems are limited in scope of evlauatuon criteria, the survey was conducted in conjunction with closed questionnaires on existing items and open questionnaires for eliciting new items. In results, suitable evaluation factors were derived for the NATM tunnel through the validation of the survey results. Also after calculating weighted value of the derived assessment item using AHP technique, a new evaluation system is proposed to meet the characteristics of the NATM tunnel, so that they can be used as reference materials for revising and supplementing detatiled guidelines in the future.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.757-763
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• 2022

In the NATM tunnel construction method for urban subway and underpass construction, various causes of disaster exist. In this study, in order to analyze the importance of disaster influencing factors during NATM tunnel excavation, the possible risk factors were analyzed through prior research such as drilling, charging and blasting, It was divided into the work items of wrinkle treatment, pumice cleanup, and support materials. Next, the final 21 detailed measurement indicators were selected through the FGI survey of related experts, and AHP (Analytic Hierarchy Process) analysis were conducted. As a result, it was found that the workers involved in the tunnel construction were the most influential disaster influencing factor.

• Explosives and Blasting
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• v.41 no.4
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• pp.9-16
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• 2023

To compare the global warming impact of the TBM and NATM method, which are representative tunnel excavation methods, a life cycle assessment was performed for each method. Life cycle assessment should compare the sum of carbon emissions by considering the pre-manufacturing stage, product manufacturing stage, usage stage, and disposal stage. However, access to TBM (Tunnel Boring Machine) manufacturing and disposal data is limited, so I had no choice but to focus on the analysis for the usage stage. In general, carbon emissions during the pre-product manufacturing stage and product manufacturing stage often exceed 90% of carbon emissions throughout the entire process. Therefore, since it is difficult to achieve the analysis goal only by comparing the usage stage, the analysis scope was expanded, and carbon emissions for the process were calculated for the NATM method with access to manufacturing data. As a result of comparing the relative impact on global warming, the carbon emissions of the TBM method were found to be higher than those of the NATM method even though TBM method was only considered for the usage stage. So there it is, the NATM method can be seen as environmentally friendly in the future when considering the impact of climate change (global warming), which has recently attracted attention among environmental impact fields.

• Explosives and Blasting
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• v.9 no.4
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• pp.22-31
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• 1991

NATM technic had been applied to Nakaya tunnel of Sin kan express R.R lines in 1975. on the worst expandable geological conditions, application of NATM method was carried out good result. Measurement data which include convergencymeter, inclinometer, extensometor load-cell, strain gage data of shotcrete stress and steel arch. was explained with slides. Induced NATM technic has been improved since 1975 as follows, specially adhesive method of shotcrete instead of spray method such as tunnel swift lining Sliding press lining, clean lining by pumping and sweeping tote lining ets.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 1994.03a
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• pp.1-11
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• 1994

현재 국내 터널의 설계와 시공은 대부분 NATM의 원리를 적용하고 있다. 그러나 터널의 설계 접근방법과 시공의 상황을 살펴보면 NATM을 국내 지질에 적용하는 것이 항상 최적이 아니라는 것을 알수 있으며, 국내 터널의 시공에 있어서도 NATM과 다른 개념의 도입과 정확한 이해가 필요하다는 것을 많은 기술자가 느끼고 있다. 따라서 보다 경제적이고 안전한 터널 시공방법의 결정을 위해 NATM의 개념과 다른 터널 설계 및 시공방법으로 노르웨이 터널 시공법(Norwegian Method of Tunnelling, NMT)을 소개하고자 한다. (중략)

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.73-73
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• 2011

현재의 NATM터널에 대한 물량은 설계도면을 기반으로 산출되는데, 이러한 방법은 수작업에 많이 의존하게 되므로 실수로 인한 물량의 오류와 사람의 능력에 따른 물량의 차이가 나타나게 된다. 본 연구는 BIM기반의 모델에서 자동적으로 물량을 산출하여 물량산출의 오류나 차이점을 바로잡고 설계변경에 따른 물량산출작업을 효율적으로 수행하려는 프로젝트에 필요한 BIM 모델링을 통한 물량산출 프로세스의 가이드라인을 제시한다. 또한, 여러 BIM 프로그램들은 각각의 모델링 및 물량산출 방식을 가지고 있어서 하나의 프로세스로 통합하기 어려운 문제가 있기 때문에 본 연구에서는 Autodesk사의 Revit Structure에 적합한 작업 프로세스에 대한 가이드라인을 제시하며 NATM 터널의 전체 구간이 아닌 본선구간만을 대상으로 한다. 본 연구는 전체적인 NATM 터널의 BIM기반 물량산출 모델링 프로세스를 BIM 모델링과 BIM 물량산출로 분리하였다. BIM 모델링 프로세스는 물량산출의 대상과 범위 설정, 모델링을 위한 CAD도면 작성, 패밀리 파일의 설정, 공종별 모델링 작업으로 구성된다. 물량산출의 대상과 범위 설정 단계에서는 NATM 터널의 CAD 파일과 수량 산출서를 분석하여 물량산출을 위한 공종별 물량산출 범위를 확정하고, 도면에 표시되지 않는 물량정보를 파악하여 물량 값을 정확하게 산출할 수 있도록 하며, 모델링을 위한 CAD도면 작성 단계에서는 Revit Structure 특성을 고려하여 모델링에 참조하는 CAD 도면을 Revit Structure에서의 모델링에 적합하게 편집해야한다. 그리고 패밀리 파일의 설정과 공종별 모델링 작업 단계에서는 CAD도면과 Revit Structure의 패밀리 파일과의 단위를 일치시키고 NATM 터널의 특성에 맞게 공종별 모델링을 실시한다. BIM 물량산출 프로세스는 모델링 데이터의 분할, 패밀리의 재구성, 물량산출로 구성된다. 모델링 데이터의 분할단계에서는 물량산출의 목적에 맞게 CAD에서 기준선을 작성하여 공종별 모델링이 작성된 패밀리 파일로 불러온 다음 모델을 분할해야한다. 그리고 패밀리의 재구성과 물량산출단계에서는 분할된 공종별 모델의 패밀리 파일을 프로젝트 파일로 불러온 다음 물량산출의 목적에 맞게 재배치하여 물량을 산출한다.

• 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.

• Tunnel and Underground Space
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• v.4 no.1
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• pp.47-54
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• 1994

NATM has been applied most of tunnel design and construction in Korea these days. But, if you observe the tunnel designing method and construction conditions, you can see that the NATM isn's usually the most suitable to Korean geology. Also most of engineers feel that it is necessary to understand the NATM correctly adn to introduce another tunnelling principle which can be applied more economically and safely. So, we'd like to introduce a new tunnelling concept. Norwegian Method of Tunnelling(NMT) by comparing the NATM. The main character of NMT is that the forward prediction of conditions and the support of tunnel is done through geological investigation in details. And it can be compared with NATM, in which the support pattern is decided by monitoring of tunnel deformation on the construction.

• Tunnel and Underground Space
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• v.20 no.2
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• pp.73-81
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• 2010

The paper presents the application of FE simulations of NATM tunnel using different constitutive models. The results from a series of two dimensional plane strain finite element analyses of medium-liner interaction for NATM are presented. Four types of constitutive models are considered, namely, linear elastic, elasto-plastic Mohr-Coulomb, Hardening-Soil, Soft-Soil model. The design for tunnels requires a proper estimate of surface settlement and lining forces. It is shown that the advanced constitutive model gives better predictions for both ground movement and structural forces.