• Title/Summary/Keyword: tunnel lining structure

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Characterization of Durability of PC panel by Accelerating Test in Deterioration Chamber and Long-Term Field Exposure Test (촉진열화 및 장기폭로시험에 의한 고성능 PC패널의 내구성능 및 열화특성)

  • Ma, Sang-Joon;Jang, Pil-Sung;Choi, Jae-Suk;Ju, Jung-Min
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.1549-1554
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    • 2008
  • In this paper, The evaluation of durability of the PC Panel lining for tunnel structure was examined through the rapid test by carbonation and freezing and thawing. Also for the purpose of improvement of durability. Namely, the durable characteristics of PC Panel lining by carbonation and freezing and thawing, was evaluated by rapid test and long-term field exposure test and main influence factors were derived. As a result of test, Correlation of accelerating test in deterioration chamber and long-term field exposure test, it will be expected that the proposed correlation well to the prediction of life expectancy of structure and is contributed greatly in the future.

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Stability Analysis of Existing Tunnel in Stratified Sedimentary Rocks Subjected to Bridge Pier Load (퇴적암 지역에서의 교각 기초 하중을 받는 기존터널의 안정성에 대한 해석적 고찰)

  • 김교원
    • The Journal of Engineering Geology
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    • v.8 no.2
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    • pp.153-161
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    • 1998
  • An anisotropic characteristics of stratified sedimentary rocks should be considered in the design of tunnel. The second line of Taegu subway is under construction through the sedimentary rocks which is stratified by alternation of shale and sandstone, and Tongsoe over bridge road is planned to be constructed along the subway line. Thus the subway twin tunnels will be subjected by the bridge load of 76.2 MN per pier that will be placed in between the twin tunnels of the subway line. A numerical analysis is carried out for the stability of the twin tunnel, and the result shows that the maximum principal stress of surrounding ground is increased by 5∼6 MPa and the additional displacement of concrete lining is reached up to 8∼10mm due to the external bridge load. For the safety operation of the subway, reinforcement of the tunnel structure is highly recommended.

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TWO TONNEL PROJECTS IN SWELLING ROCKS

  • Lee, Young-Nam;Ha, H.B.
    • Proceedings of the Korean Geotechical Society Conference
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    • 1990.10a
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    • pp.35-50
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    • 1990
  • This paper describes the importance of incorporating the titre-dependent deformation behaviour in the design and construction of tunnels in swelling rocks. Two tunnel projects, in which authors got involved in Canada, are chosen to demonstrate the importance. In diversion tunnels for Oldman River Dan Projects time-dependent deformation characteristics of the mudrocks obtained from teat tunnel program were neglected in the design and construction of the tunnels and several sectional of concrete lining in tunnels were cracked extensively. In SABNGS No.3 Projects an extensive experimental program was carried out to study time-dependent deformation behaviour of highly swelling Queenston shale, with the air of establishing the constitutional relationship for the rock-structure time interaction analysis.

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Evaluation of Fire-Resistant Performance for Tunnel Lining Concrete with Heating Temperature-Time Curves (시간가열온도곡선에 따른 터널라이닝 콘크리트의 내화성능 평가)

  • Lee, Chan-Young;Shim, Jae-Won;Ahn, Tae-Song;Lim, Chae-Hyeok
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.477-480
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    • 2006
  • In this study, evaluation of fire-resistant performance for polypropylene fiber-mixed mortar was performed to establish specification for stability of tunnel structure against fire afterward. In the fire-resistant performance test with mix proportion of polypropylene fiber, cracks were observed for mortar under 0.15% of fiber content, but micro-cracks were remarkably reduced for mortar more than 0.2% of fiber content. From the results, we are concluded that optimal mix proportion of polypropylene fiber is $0.20{\sim}0.25%$.

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Numerical study on structural reinforced effects of concrete lining by spray-applied waterproofing membrane (차수용 박층 멤브레인 설치에 따른 콘크리트 라이닝의 구조적 보강효과에 관한 수치해석 연구)

  • Lee, Chulho;Lee, Kicheol;Kim, Dongwook;Choi, Soon-Wook;Kang, Tae-Ho;Chang, Soo-Ho
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.3
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    • pp.551-565
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    • 2017
  • A spray-applied waterproofing membrane which consists of polymers has a relatively higher constructability and adhesion than the conventional sheet-type waterproofing materials. Additionally, the spray-applied waterproofing membrane generally shows a waterproofing ability as a composite structure with shotcrete or concrete lining. Because its purpose is waterproofing at the structure, structural effects were not well reported than waterproofing abilities. In this study, structural effects of the membrane-attached concrete lining were evaluated using 3-point bending test by the numerical method. From the analysis, a load-displacement behavior of the concrete lining and fracturing energy after yielding were compared with various conditions. Consequently, concrete lining with spray-applied waterproofing membrane shows higher flexural strength and fracturing energy than the single-layer concrete lining.

Measurement of compressive and tensile strain in concrete structure with FBG sensor fixture (광섬유격자센서의 콘크리트구조물에의 고정과 압축 및 인장 변형의 측정)

  • Kim, Ki-Soo;Kim, Young-Jin;Moon, Dae-Jung;Kim, Seong-Woon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.149-152
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    • 2008
  • FBG sensor system is applied to the concrete lining structure in Taegu subway. Near the structure, the power cable tunnel construction started. We wanted to measure the deformation of the structure due to the construction by the FBG sensor. The applied sensor has the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well

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Study of fire protection performance of newly developed cementitious fire protection material for application to architectural building (건축구조물에 적용하기위한 신개발 시멘트계 내화재료의 내화성능에 관한 연구)

  • Kim, Jang-Ho;Park, Hae-Geun;Lee, Myeong-Sub;Won, Jong-Pil;Lim, Yun-Mook;Lee, Kyong-Min
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.633-636
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    • 2006
  • High-rise and large size buildings require high strength concrete and steel structure as a necessity. However, high strength concrete and steel structure are strong material but have a weakness to high temperature. Therefore, fire protection is a matter that must be considered very importantly in design for structure of high strength concrete and steel. Fire proof board that is existing method for fire proof has relatively low performance in fire protection emphasizes the need of new fire protection material due to the using of in numerable inflammables like plastics. The objective of this study is to understand the fire-resisting performance of newly developed fire protection material for building. This paper describes the results of fire tests using ISO curve that is fire protection regulation for buildings of the newly developed cementitious fire protection coating material applied concrete tunnel lining specimens.

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Monitoring System For The Subway Structures Using Prestrained FBG Sensors Fixed With Partially Stripped Fibers (부분탈피 고정방식 프리스트레인 가변형 광섬유격자센서를 이용한 지하철 구조물 변위 모니터링시스템)

  • Kim, Ki-Soo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.6
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    • pp.607-613
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    • 2008
  • A monitoring system for the subway structures using prestrained FBG sensors fixed with partially stripped fibers was developed. The sensor packages had pre-strain controllable fixtures. Tensile and compressive strain of the structure could be measured without slip. The FBG sensor system was applied to the concrete lining structure in Taegu subway. Near the structure, the narrow tunnel construction, for the electric power cables and telecommunication cables, started. We wanted to measure the deformations of the subway structures due to the construction by the FBG sensor. The applied sensors had the gauge length of 1 meter to overcome the inhomogeneity of the concrete material with enough length. In order to fix tightly to the structure, the partially stripped parts of the sensor glued to the package and slip phenomenon between fiber and acrylate jacket was prevented. Prestrain of the sensor was imposed by controlling the two fixed points with bolts and nuts in order to measure compressive strain as well as tensile strain. The behavior of subway lining structure could be monitored very well.

Web-based Monitoring System for a Railroad Tunnel by Wireless Internet (무선인터넷을 이용한 웹 기반 원격지 철도터널의 계측관리)

  • Lho, Byeong-Cheol;Kim, Jong-Woo;Kim, Jeong-Hoon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.3
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    • pp.159-164
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    • 2006
  • Mobile communication with wireless modem can be powerful tool in web-based structural health monitoring system in which power and communication method are crucial points. In this study, the major reasons of side cracks in tunnel lining are studied by FEM analysis. In addition, a web-based monitoring system using mobile communication with wireless modem is applied to the tunnel structure to monitor the long term behavior of the side cracks. The field application shows that CDMA is useful method for structural health monitoring system which installed long distance away.

Discrete element numerical analysis for simulating trapdoor tests to assess loosening earth pressure on tunnel linings

  • Chaemin Hwang;Junhyuk Choi;Jee-Hee Jung;Hangseok Choi
    • Geomechanics and Engineering
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    • v.38 no.6
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    • pp.571-581
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    • 2024
  • Concrete linings in tunnels constructed by drilling and blasting such as NATM serve as a secondary support structure. However, these linings can face unexpected earth pressures if the primary support deteriorates or if ground conditions become unfavorable. It is crucial to determine the loosening earth pressure that allows the lining to maintain its structural integrity and prevent damage caused by this pressure. This study proposes a numerical model for simulating the trapdoor test and developing a method for calculating the loosening earth pressure. The discrete element method (DEM) was employed to describe the soil characteristics around the tunnel. Using this numerical model, a sequence of experimental trapdoor steps was simulated, and the loosening earth pressure was analyzed. Contact parameters were calibrated based on an analysis of a triaxial compression test. The reliability of the developed model was confirmed through a comparison between simulation results and laboratory test findings. The model was used to calculate the contact force applied to the trapdoor plate and to assess the settlement of soil particles. Furthermore, the model accounted for the soil-arching effect, which effectively redistributes the load to the surrounding areas. The proposed model can be applied to analyze the tunnel's cross-sectional dimensions and design stability under various ground conditions.