• Title/Summary/Keyword: tunnels

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Earthguake Resistant Design of Submerged Tunnels (침리터널의 내수설계)

  • 박승범
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.23 no.4
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    • pp.32-40
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    • 1981
  • A lot of submerged tunnels which cross revers and channels have been constructed in the USA, European countries and Japan. It is very important to consider anti-seismicity of the tunnels when they are located in active seismic zone. Fortunately, the submerged tunnels have never been damaged by earthquakes, however a umber off surveys and experiments to examine the anti-seismicity of the submerged tunnels have been carried out from various points of view. the dynamic characteristics of the submerged tunnels which are buried in the ground and have long total length from that of the structures above ground. 'Specificitions of Earthquake Resistant Desion of Submerged Tunnels' was established by the Japan Society of Civil Engineers in 1975. These specifications greatly promote the construction of the submerged tunnels. In this technical paper, the outline of the construction and a few methods of earthquake resistant designs for the tunnels: earthquakes observations, indoor experiments by shaking table, and numerical analysis by computer are also mentioned.

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A Consideration on the Stability Analysis Method of Great Deep Tunnels (대심도 터널의 안정성 해석 방법에 대한 고찰)

  • 김주봉;안경철;김영준
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.301-308
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    • 1999
  • The construction of great deep tunnels has become an important part in tunnel construction especially in the mountain area. Therefore, it is necessary to establish the proper method of the stability analysis for great deep tunnels. In this paper presents the study result on the followings: (1) Evaluation of practical problem on the stability analysis of great deep tunnels. (2) Proposal of the proper on method for great deep tunnels analysis considering the depth of overburden. (3) Understanding of the ground behavior of the great deep tunnel through the sensitivity analysis and the parametric study.

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The Stability Assessment of ASSM Tunnels in Service (공용중인 ASSM 터널의 안정성 평가)

  • Kwon, Young Jeong;Park, Min Chul;Shin, Hyo Hee;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.5
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    • pp.150-159
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    • 2011
  • The need of securing the stability and extending service lives by efficient maintenance of deteriorated tunnels for several decades has been increased. The stability and the usability of conventional tunnels can be decreased by change of physical properties of the surrounding ground, geometrical properties of the tunnel, an underground water level, environmental conditions, oxidation of lining and the breakdown of constituent materials. In respect of a long-term view, it is need to check all sorts of degradation, the degree of damage and durability to improve the serviceability and to come up with measures to maintain effectively. This paper is about study to analyze the stability of conventional tunnels(American Steel Support Method. ASSM). Three tunnels are chosen in those built in the 1930s and 1960s and the locations of tunnels are selected variously(ChungCheong, GyungBuk, GangWon, Jeolla, etc.) to secure reliability of this study. The state of repair and reinforcement of linings, cracks, and thickness and strength of lining of conventional tunnels in service are researched, compared and analyzed. The crack gauge, the GPR, the schmitt hammer was used for the crack investigation, cavitation, the strength respectively. By using these, the comparative analysis for conventional tunnels was conducted. As a result, there are more cracks in tunnels built in the 1930s than those of tunnels built in the 1960s, and lining strength of the 1930s is higher than those of the 1960s. The thickness of lining in tunnels built in the 1960s is higher than those in tunnels built in the 1930s. In proportion to thickness, cavitation occurred more frequently in tunnels built in the 1960s compared to those in tunnels built in the 1930s.

Improvement Plan of Fire-Related Laws of Disaster Prevention Facilities of Road Tunnels (도로터널 방재시설의 소방관계법령 개선방안)

  • Seo, Hyo-Seon;Whang, Young-Kwon;Lee, Seung-Chul
    • Fire Science and Engineering
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    • v.33 no.2
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    • pp.124-131
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    • 2019
  • When a fire occurs in a road tunnel, it is likely to develop into a major disaster because of its sealed structural characteristics. Because of this, a range of disaster prevention facilities should be installed, and they should show their appropriate functions in fire prevention and response. In addition, the installation of essential disaster prevention facilities is missing due to the lack of considering an extension of continuous tunnels and soundproof tunnels. For these reasons, it was judged that an amendment to the law would be necessary. Therefore, this paper reviewed the changes in domestic laws related to the disaster prevention facilities of road tunnels, and the results of the study on the parts that need to be revised in the fire-related laws through a comparative analysis between laws are as follows. First, consecutive tunnels should consider the sum of the extensions of the individual tunnels and ensure that the soundproof tunnels are included in the category of tunnels in the law. In this way, the necessary disaster prevention facilities should be installed. Second, it is necessary to secure a legal justification for installing disaster prevention facilities in tunnels. Therefore, it is essential that water mist fire extinguishing system facilities, emergency broadcasting facilities, and leading lights, which are excluded from installation in tunnels, are specified in the Fire-related laws. Third, to specify in the law that air respirators must be provided in the tunnel is necessary from the viewpoint of the field response. Accordingly, it will make a great contribution to the fire-fighting activities and the life-saving efforts by fire-fighters.

A Study of Proper Space between the Escape Tunnels in the Long Railway Tunnel (철도장대터널의 대피통로 최적간격에 관한 연구)

  • Kim Dong Gi;Park Byung Eun;Rha Sang Ju;Park Jong Kwaun
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.880-885
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    • 2004
  • When a fire takes place, the escape tunnel which could prevent passengers and the crew from disasters would be most important facility among railway tunnel facilities for prevention of disaster. A shorter space between the escape tunnels is much better for safety because of short escape time. The establishment of short space escape tunnels(driftways) in the single track parallel tunnel is much easier. The establishment of long space escape tunnels(inclined shafts, vertical shafts) in the double track is much more advantageous economically. We, therefore, compared the movement time of smog originated from fire with the escape time of the crew and passengers for setting up the best space between the escape tunnels in the double track tunnel. We could calculate the best space between the escape tunnels in the double track tunnel properly by computer simulation.

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A Numerical Study on the Reinforcement Method of a Pillar Using Tension Bolts at the Connecting Part between 2-Arch Tunnels and Parallel Tunnels (2-Arch 터널과 병렬 터널 접속부에서의 텐션볼트를 사용한 필라 보강 방법에 대한 수치해석)

  • Park, Yeon-Jun;Choi, Jae-Jin
    • Tunnel and Underground Space
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    • v.25 no.5
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    • pp.470-486
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    • 2015
  • Two-arch tunnels require minimal spacing between the 2 tunnels and thus occupy small amount of land compared to parallel tunnels. But it is rather expensive. The parallel tunnel is not as expensive, but it requires more land than 2-arch tunnels. This may cause a problem when there is a land shortage. The new design is to connect these two types of tunnels by another pair of parallel tunnels where the separation distance is gradually increasing. The applicability of this new design to the cases where rock condition is not even fair has to be verified since the width of the pillar between the connecting tunnels can be quite narrow. Therefore both two and three dimensional numerical analyses were conducted and pillar stability was examined for rock classes IV and V in two different ways. Results showed that this new design is still effective for poor rock conditions if central pillar is properly reinforced by tension bolts as long as overburden is less than five times of the tunnel diameter.

A numerical study on the ventilation characteristics of rainfall in road tunnel (강우변화를 고려한 도로터널의 환기특성에 관한 수치해석)

  • Lee, Ho-Hyung;Lee, Seung-Chul
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.17 no.3
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    • pp.341-351
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    • 2015
  • When rainfall occurred on road tunnel, that is likely to have influence upon ventilation force in the tunnels but the tunnels ventilation system did not consider factors of rainfall. Thus, this study investigated effects of rainfall upon ventilation force in the tunnels at no rainfall and changing of rainfall by 3 dimensional numerical method. Flow rate into road tunnels decreased as many as 52.34% at rainfall of 150 mm/hr, and pressure drop of road tunnel between entrance and exit decreased as many as 22.22%, so that rainfall had influence upon ventilation force in the tunnel. The number of necessary jet fan in road tunnels is 12 at no rainfall but, when rainfall of 80 mm/hr on road tunnels, the number of necessary jet fan in road tunnels is 16, when rainfall of 150 mm/hr on road tunnels, the number of necessary jet fan in road tunnels is 17. So, factor of rainfall should be considered at estimation of ventilation system of road tunnel.

Numerical modeling of two parallel tunnels interaction using three-dimensional Finite Elements Method

  • Nawel, Bousbia;Salah, Messast
    • Geomechanics and Engineering
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    • v.9 no.6
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    • pp.775-791
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    • 2015
  • Due to the extension of communication ways (metro, highways, railways), hence, to improve traffic flow imposes often the difficult crossing that generally drive to the construction of underground works (tunnel, water conveyance tunnel...) plays a major role in the redevelopment of urban areas. This study is focused on the assessment of the interaction response of parallel tunnels, so this study uses the results from the simulation of two tunnels to illustrate a few observations that may aid in practical designs. In this article, simultaneous drilling of highway's twin tunnels is simulated by means of Finite Element Method (FEM) implemented in Plaxis program. So the treated subject appears in a setting of geotechnical where one can be to construct several tunnels sometimes in a ground of weak mechanical characteristics. The objective of this study is to simulate numerically the interaction effects caused by construction of two parallels tunnels. This is an important factor in the study of the total answer of the problem interaction between parallels underground works. The importance of the effects transmitted is function of several parameters as the type of the works, and the mechanical characteristics (tunnel size, depth, and the relative position between two tunnels, lining thickness...). This article describes numerical analyses of two parallels tunnels interaction. This study will be applied to a real case of a section tunnel T4 of the highway East-West (Algeria); the study presented below comprises a series of numerical simulations of two tunnels using the computer program Plaxis which is used in the analyses is based on Finite Element Method.

Experimental and Numerical Study of Interactions Between Parallel Tunnels (평행근접터널의 상호거동에 대한 실험 및 수치해석적 연구)

  • Kim, Sang-Hwan
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.181-187
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    • 2003
  • This paper describes a study of the influence of shield tunnel construction on the displacements and stresses induced in the linings of existing nearby parallel tunnels. The paper presents a brief review of a set of laboratory scale model research programme investigating the influence of tunnel proximity and alignment, liner stiffness on the nature of the interactions between closely spaced tunnels in clay. A total of two sets of carefully controlled physical model tests were performed. A cylindrical test tank was developed and used to produce clay samples of Speswhite kaolin. In each of the tests, three model tunnels were installed in order to conduct two interaction exts that have been carried out to investigate the interaction problem between parallel tunnels. The results of these tests are compared with the results of finite element analysis to investigate the techniques that must be used to obtain reliable numerical solutions to this type of problem.

A study on design concept and analysis method of closely spaced tunnels (근접터널의 설계개념 및 해석기법에 대한 연구)

  • Kim, Sang-Hwan
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.5 no.1
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    • pp.33-42
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    • 2003
  • The use of tunnels in major transportation schemes has increased considerably during the last decade especially in urban area. The state of stress and the displacements in a zone around a tunnel will be modified by the construction of a tunnel. Therefore, it is necessary to study the influence factors for the nearby tunnels. This paper describes the design concept and analysis method on the closely spaced tunnels. The main purpose of the present paper is to study the influence of tunnel construction on the behaviour induced in the liners of nearby tunnels. The effects of tunnel proximity and alignment, liner stiffness and settlements are also reviewed in this paper. The paper then introduces the design and analysis methods for the closely spaced tunnels which is very useful in practice.

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