• Title/Summary/Keyword: NATM Composite lining Tunnel

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Study on Applicability of NATM Composite Lining Method (NATM Composite 라이닝 공법의 적용성 연구)

  • Ma, Sang-Joon;Kang, Eun-Gu;Kim, Dong-Min
    • Journal of the Korean Geotechnical Society
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    • v.27 no.12
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    • pp.69-84
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    • 2011
  • This paper presents the applicability of NATM Composite Lining method in domestic tunnel construction sites. Firstly, in order to produce high quality PC Panel, optimal steam curing condition is reviewed. And in preparation for fire inside the tunnel, the fire-resistance test of PC Panel is carried out. The constructability of NATM Composite Lining method and the drainage ability of light-weight foamed mortar is also evaluated through field construction test. And PC Panel combination program is developed to calculate the quantity of PC Panel efficiently. Besides, economic evaluation for NATM Composite Lining method is conducted. From this research, it is clearly found that NATM Composite Lining method is applicable to domestic tunnel construction site.

Basic Study for Development of NATM Composite Lining Method (NATM Composite 라이닝 공법 개발을 위한 기초 연구)

  • Ma, Sang-Joon;Kang, Eun-Gu;Kim, Dong-Min;Shin, Joo-Yul
    • Journal of the Korean Geotechnical Society
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    • v.27 no.12
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    • pp.53-68
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    • 2011
  • This paper presents the fundamental parameters for designing the NATM Composite Lining to be used in NATM tunnel construction. Firstly, the concept of NATM Composite Lining behaviour is introduced and reviewed in construction-performance. For the fundamental study, the optimal mix ratio tests and backfill material property tests to develop high-quality composite lining (PC panel lining) are fundamentally carried out. And the light-weight foamed mortar which is used for backfill material is developed. Full-scale loading tests to verify a performance of the NATM Composite Lining is also performed. From this research, it is clearly found that the NATM Composite Lining is very applicable method to considerably increase the stability and constructability of tunnel structure.

A Study on the Proper Transfer Distance for Minimizing Air Flotation Loss of Backfilling Material of NATM Composite lining Tunnel in the Model Test (충진 모형실험을 통한 NATM Composite 라이닝 터널 뒤채움재의 기포손실 최소화를 위한 적정 이송거리 고찰)

  • Ma, Sang-Joon;Choi, Hee-Sup;Lee, Heung-Soo;Kim, Kyung-Duk
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1555-1558
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    • 2008
  • In this paper, result of whole test, When the Transfer Distance is increasing, Strength of Backfilling Material of NATM Composite lining Tunnel due to increasing Gravity was increased, but that is higher the Air Flotation than increasing Strength. So, That was predicted a drop of Permeability. And Performing the placing Lightweight Foamed Mortar, we think that it's performance in drain material was lost. Therefore We conclude that Proper Transfer Distance that taking Permeability through minimizing of Air Flotation Loss and getting the Need Strength is 50m.

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An Evaluation of the Mechanical Property for the Backfilling Material of the NATM Composite Lining Tunnel using the Lightweight Foamed Mortar (경량기포 모르타르를 이용한 NATM Composite 라이닝 터널 뒤채움재의 역학적 특성 평가)

  • Ma, Sang-Joon;Choi, Hee-Sup;Kim, Dong-Min;Lee, Heung-Soo;Kim, Kyung-Duk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.717-720
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    • 2008
  • This paper, an evaluation of the mechanical property for the backfilling materials of the NATM Composite lining tunnel using the lightweight foamed mortar, relates to the performance of permeability, compressive strength and unit volume weight. Therefore, this study is aimed to prove the three main factor that refered to the above line for development of new tunnel method. As the result of this study, it would be confirmed that the D mix is better than other mixs a side of all tests and its relation that is for the tunnel backfilling materials.

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Numerical Analysis on the Crack Control of Concrete Lining Reinforced by Composite Fibers (복합섬유보강 콘크리트 라이닝 부재의 균열제어를 위한 수치해석적 연구)

  • Yang, Woo-Shik
    • Journal of the Korean Geosynthetics Society
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    • v.9 no.2
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    • pp.41-50
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    • 2010
  • The concrete lining of a tunnel constructed by NATM used to be regarded as facing material which does not support any load from the surrounding ground. But the recent appraisal of the decrepit tunnels revealed that rockbolts and shotcrete deteriorate with time resulting in loss of supporting capability. Consequently, concrete lining has to support part of the load which used to be supported by rockbolts and shotcrete, and thus should be regarded as the final supporting structure in a tunnel. One of the common, and perhaps the most serious problem in concrete lining is the longitudinal cracks taking place at the tunnel crown. The longitudinal cracks, mostly related to the construction procedures, can be developed by many reasons such as the lack of thickness, wrong materials, bad curing environment, and excessive external forces. Many efforts has been made to control and suppress these cracks but efficient and economic way is yet to be found. For efficient crack control in concrete lining, reinforcement by composite fibers, which is the mixture of steel fiber and nylon fiber, is suggested in this study.

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Performance Assesment of the Existing Tunnel drain and higher permeable for the In-plane Test (평면투수 실험을 통한 기존 배수재와 고투수성 배수재의 성능 평가)

  • Ma, Sang-Joon;Lee, Heung-Soo;Choi, Hee-Sup;Kim, Kyung-Duk
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1581-1584
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    • 2008
  • In this study, performance Assesment of the existing tunnel drain and higher permeable for the In-plane Test. Two separate simulation tests from geotexitile and Lightweight Foamed Mortar compare. perfomed:the one is the in-plane test and the other is the clogging phenomenon test. As a result, NATM Composite used to Ligheweight Foamed Mortar pemability 80%, more than existing tunnel drain. Also, clogging phenomenon test do low assesment more than existing tunnel drain geotextile.

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Evaluation of the Field Application of the Ready-mixed Shotcrete using the Synthetic Fiber (합성섬유를 혼입한 레디믹스트 숏크리트의 현장적용성 평가)

  • Choi, Hee-Sup;Nam, Kwan-Woo;Nam, Gi-Mok;Seo, Sin-Seok
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1536-1539
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    • 2009
  • In this paper, The Ready-mixed Shotcrete which Factory with automatic production system is made Materials using synthetic fiber is evaluated the field application. Result of whole test, synthetic fiber(PP, PVA) is indicated almost equal result of steel fiber by rebound rate, compressive strength and bending test. especially, PP fiber(40mm, 12kg) is showed that bending strength and toughness is better than steel fiber, also I reason in that field application of synthetic fiber(PP, PVA) is proved.

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The First Case Study of TBM Pre-Excavation Type 2-Arch Tunnel in Korea (국내 최초 TBM선굴진 2-Arch터널 설계사례 연구)

  • Hyung-Ryul Kim;Sang-Jun Jung;Jun-Ho Kang
    • Tunnel and Underground Space
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    • v.33 no.4
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    • pp.255-264
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    • 2023
  • As the demand for urban underground space increases recently, urban tunnel planning is actively progressing. In the urban area, a underground station is planned in consideration of the living environment of residents, and 2-arch tunnel is applied for the stability of existing structures and reduction of environmental damage. However, since the depth of weak rock mass is deeply distributed in the urban area due to severe weathering, careful planning is required to secure tunnel stability. In addition, if TBM mechanical excavation is applied as the main tunnel excavation method considering the composite ground in urban area, the construction connectivity with the 2-arch tunnel of the NATM concept may be deteriorated. In this study, the design case of applying TBM pre-excavation type 2-arch tunnel for the first time in Korea was mainly described. The main considerations for the segment design of TBM pre-excavation type 2-arch tunnel were explained for side tunnels. Also, a stability analysis was conducted to verify the effectiveness and adequacy of the TBM pre-excavation type 2-arch tunnel.