• Title/Summary/Keyword: lining concrete

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A Study on the Design Loads of NATM Tunnel Concrete Lining (NATM 터널 콘크리트라이닝 설계하중에 관한 연구)

  • 천병식;신영완
    • Tunnel and Underground Space
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    • v.11 no.2
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    • pp.96-108
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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. Structural analyses are done in various load combinations, and the member forces(moment, axial force and shear force) are compared. The adequate load combination of rock load and water pressure is proposed.

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Lining of Reinforced Spun Concrete Pipes using Polymer-Modified Mortars (폴리머 시멘트 모르타르를 이용한 원심력 철근콘크리트관의 라이닝)

  • 조영국
    • Journal of the Korea Concrete Institute
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    • v.13 no.4
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    • pp.406-413
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    • 2001
  • Up to this day, reinforced spun concrete pipes have been widely used as drain pipes. However, many reinforced spun concrete pipes are exposed to the deteriorated environment such as freezing-thawing damage and chemical attack by the growth of a sulfur-oxidizing bacterium isolated from corroded concrete. The purpose of this study is to evaluate the effects of lining by polymer-modified mortar using polymer dispersions as cement modifier on the development in durability of reinforced spun concrete pipe. The polymer-modified mortars were prepared with various polymer types and polymer-cement ratios, and tested for compressive and flexural strengths, acid, freezing-thawing, and heat resistances. And then, the reinforced spun concrete pipe product lined by polymer-modified mortars was tested for adhesion in tension and surface conditions according to curing temperatures in the field. From the test results, it is apparent that the polymer-modified mortars have good mechanical properties and durability as a lining material. In practice, all polymers can be used as lining the materials for reinforced spun concrete pipe, and types of polymer, and polymer-cement ratio and curing conditions are controlled for a good lining product.

A study on the cracking of tunnel lining by measurement and numerical analysis (계측 및 수치해석을 통한 터널 라이닝의 균열 원인 연구)

  • Hwang, Hak;Jung, Hun-Chul;Kim, Yu-Seok
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.33-40
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    • 2001
  • In this research, the cracking of tunnel concrete lining was investigated and analyzed through long-term measurement and nonlinear numerical analysis. For one year after the casting of lining, the stresses and strains were measured by the sensors installed in hard rock tunnel lining. The measurements showed that only small stresses which were less than cracking stress occurred in every survey sections regardless of sensor directions. It could be induced that the external load applied to the lining was small or ignorable. Also, it was carried out short-term numerical analysis based on such site condition as ambient temperature, the- degree of overbreak and mold staying period. Long-term numerical analysis based on creep & shrinkage and nonlinear cracking was carried out. The output showed that construction condition and ambient environments could make the lining concrete crack without external loads. The cracks formed in this process does not indicate the structural instability of the tunnel.

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A Study on the Bearing Capacity of Steel Composite Concrete Lining Board (강합성 콘크리트 복공판의 내력시험에 관한 연구)

  • Paik, Shinwon;Kim, Yongon
    • Journal of the Korean Society of Safety
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    • v.27 no.6
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    • pp.122-126
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    • 2012
  • Steel lining board usually is used as a floor on the temporary steel bridges. It also is installed in the subway construction site. However, in particular in subway construction, renovations and site of old bridges, these steel lining board structures have a problem such as noise, accidents and slip hazards. So steel composite lining board is being developed to solve this problem. Steel composite lining board consists of compressive concrete showing excellent performance in slip, durability, resistance and noise, lower tensile and shear steel showing high safety, effective and superior workability in many respects. Steel composite lining board structure gradually is used in many construction sites, because it has a high quality such as durability, little noise and slip. In this study, flexural tests of steel composite lining board in accordance with welding patterns were conducted to compare the performance of the structure.

A Method of Tunnel Analysis for Automatic Concrete Lining Construction Method (자동 터널라이닝 공법에 대한 해석기법)

  • 정한중;강석화;장성욱;이승욱
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.32-37
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    • 1993
  • A method of tunnel analysis for a new type of tunnel construction method (ACLCM, Automatic Concrete Lining Construction Method) is presented here. ACLCM is an unique tunnel construction method which provides concrete lining at the end of shield machine by extruding concrete into the space between the excavated ground surface and the inner form (Automatic Concrete Lining Machine). Since behaviors of tunnel and the surrounding soils are greatly influenced by the construction method, existing tunnel design methods may not be applicable to the design of ACLCM tunnel. In this study, a method of ACLCM tunnel analysis is suggested to provide the prediction of behavior of ACLCM tunnel and surrounding soils as well as to check up the safety during the construction and after the completion of ACLCM tunnel

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Vibration analysis of mountain tunnel lining built with forepoling method

  • Gao, Yang;Jiang, Yujing;Du, Yanliang;Zhang, Qian;Xu, Fei
    • Smart Structures and Systems
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    • v.21 no.5
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    • pp.583-590
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    • 2018
  • Nowadays, many tunnels have been commissioned for several decades, which require effective inspection methods to assess their health conditions. The ambient vibration test has been widely adopted for the damage identification of concrete structures. In this study, the vibration characters of tunnel lining shells built with forepoling method was analyzed based on the analytical solutions of the Donnell-Mushtari shell theory. The broken rock, foreploing, rock-concrete contacts between rock mass and concrete lining, was represented by elastic boundaries with normal and shear stiffness. The stiffness of weak contacts has significant effects on the natural frequency of tunnel lining. Numerical simulations were also carried out to compare with the results of the analytical methods, showing that even though the low nature frequency is difficult to distinguish, the presented approach is convenient, effective and accurate to estimate the natural frequency of tunnel linings. Influences of the void, the lining thickness and the concrete type on natural frequencies were evaluated.

An Experimental Study on the Application of Fly Ash for Lining Concrete (라이닝콘크리트에서의 FA적용에 관한 실험적 연구)

  • 최세진;임정열;김완영;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.151-154
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    • 1999
  • The lining concrete of water tunnel is a structure that is constructed to prevent from corroding of the rock around tunnel and reduce the deterioration of geology by flowing water, and to improve the durability of tunnel, which must not only economy, stability but also satisfy the engeneering properties of concrete. This is an experimental study to analyze th usability of fly in the tunnel lining concrete. For this purpose, after select the mix proportion of plain concrete and concrete using fly ash(the replacement of 15 and 30% by weight of cement) to satisfy slump, air content and compressive strength through the mix design, the test of slump, setting time, compressive strength, tensile strength, drying shrinkage and adiabatic temperature rise was performed. According to test results, it was found that FA 15 concrete was more effective than the others to reduce drying shrinkage as well satisfy other engineering properties.

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Development of Steel-Concrete Composite Lining Board using Section Shape Steel (형강을 이용한 강-콘크리트 합성복공판 기술개발)

  • Oh, Soo-Cheol;Yang, Hae-Sool
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.3
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    • pp.67-75
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    • 2008
  • This research is to develop the steel-concrete composite lining board using section shape steel. This lining board adopts section shape steel, rectangular pipe and H-beam, instead of roll-formed steel member commonly used in other composite lining board. Consequently, it reduces fabrication effort. Efficient section which can reduce the weight of steel of the lining board is made by placing the neutral axis of the section near the lower surface of concrete. Behavior of composite section is improved by adding bolts as shear connector. Static and fatigue tests were conducted to verify the performance of the composite lining board developed. The test results indicate that serviceability as well as safety of the lining board developed is secured with good margin and reduction of steel weight can be made about 27% compared with other composite lining boards.

Study on the Improvements and the Problems of Tunnel Lining in Korea. (기존 라이닝 공법의 문제점과 개선방향에 대한 고찰)

  • 임수빈
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.135-137
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    • 2002
  • NATM has been generalized as a tunnelling method since the early of 1980's in Korea. But the concrete lining as the secondary supporting system based on the NATM concept has not been treated in tunnelling construction. The Purpose of this paper is to study the improvements and the problems of concrete lining in the rock tunnel

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Assessment of time-dependent behaviour of rocks on concrete lining in a large cross-section tunnel

  • Mirzaeiabdolyousefi, Majid;Nikkhah, Majid;Zare, Shokrollah
    • Geomechanics and Engineering
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    • v.29 no.1
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    • pp.41-51
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    • 2022
  • Tunneling in rocks having the time-dependent behavior, causes some difficulties like tunnel convergence and, as a result, pressure on concrete lining; and so instability on this structure. In this paper the time-dependent behaviour of squeezing phenomenon in a large cross section tunnel was investigated as a case study: Alborz tunnel. Then, time-dependent behaviour of Alborz tunnel was evaluated using FLAC2D based on the finite difference numerical method. A Burger-creep viscoelastic model was used in numerical analysis. Using numerical analysis, the long-time effect of squeezing on lining stability was simulated.This study is done for primary lining (for 2 years) and permanent lining (for 100 years), under squeezing situations. The response of lining is discussed base on Thrust Force-Bending Moment and Thrust Force-Shear Force diagrams analysing. The results determined the importance of consideration of time-dependent behaviour of tunnel that structural forces in concrete lining will grow in consider with time pass and after 70 years can cause instability in creepy rock masses section of tunnel. To show the importance of time-dependent behavior consideration of rocks, elastic and Mohr-Coulomb models are evaluated at the end.