• Title/Summary/Keyword: 가시설

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A Study on the Self-contained Earth Retaining Wall Method Using Bracing (브레이싱을 이용한 자립식 흙막이 공법에 관한 연구)

  • Kim, Jong-Gil
    • Journal of Digital Convergence
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    • v.17 no.3
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    • pp.205-213
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    • 2019
  • In a construction site, excavation work has a close relation with temporary earth retaining structure. In order to build the underground structure most effectively in a narrow space, prevent soil relaxation of the external behind ground in excavation work, and maintain a ground water level, it is required to install a temporary earth retaining structure that secures safety. To prevent soil washoff in underground excavation work, the conventional method of temporary earth retaining structure is to make a temporary wall and build the internal support with the use of earth anchor, raker, and struct for excavation work. RSB method that improves the problem of the conventional method is to remove the internal support, make use of two-row soldier piles and bracing, and thereby to resist earth pressure independently for underground excavation. This study revealed that through the field application cases of RSB method and the measurement result, the applicability of the method for installing a temporary earth retaining structure, the assessment result, and displacement all met allowable values of measurement, and that the RSB method, compared to the conventional method, improved constructability and economy.

Nonlinear Dynamic Behavior of Temporary Rail Considering the Effect of Vibration (진동영향을 고려한 가시설 레일의 동적 거동 특성)

  • Lim, Hyung Joon;Ryu, Dong Hyeon;Won, Jong Hwa;Kim, Moon Kyum
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.2A
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    • pp.171-178
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    • 2008
  • The object of this study is to propose a rate of vibration increase in the analysis of temporary rail non-fixed in the vertical direction and characterize the nonlinear dynamic behavior of temporary rail while considering longitudinal and latitudinal load, vibration and lifting. The rate of vibration increase is proposed through measurement of an actual structure that is largely affected by loading and vibration of the superstructure. Dynamic behavior was additionally characterized by the dynamic response resulting from nonlinear dynamic finite element analysis with vehicle loading, including the rate of vibration increase. As a result, the rate of vibration increase by the vibration of an Auto Bar Machine is determined as 7% and the maximum stress in the analysis of the nonlinear rail is increased 14.5% over that of linear rail, and temporary rail is shown to be very sensitive to the velocity of the superstructure.

Evaluation of the Lateral Influence Range on Temporary Structures for a Train Operating at 80km/h (시속 80km/h의 열차 운행시 가시설 구조물에 미치는 수평영향범위 평가)

  • Jong-Chul Kim;Yeong-Bae Kim;Tae-Hyun Hwang;Kang-Il Lee
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.2
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    • pp.35-45
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    • 2023
  • In accordance with the urban development project, cases of constructing temporary wall structures for ground excavation in the vicinity of railway structures are increasing. In addition, the complaints about train vibration are also increasing from people living in large buildings newly built after installing the temporary wall structures. In order to solve this problem, a method for reducing train vibration is considered from the design stage of the building, and a vibration reduction system is installed on the structure when the building is newly constructed. However, the vibration reduction method established at the structure design stage can be determined through the results of field measurements or dynamic numerical analysis for a specific area, and there is a limit to evaluating whether the established vibration reduction method is appropriate due to the lack of objective research data. Therefore, in order to provide objective basic data when establishing a vibration reduction method, this study performed the dynamic numerical analysis for a operating train with a speed 80km/h by applying differently the depths of railway structures, the distances between railways and temporary wall structures, and ground conditions. It was found that the range of influence of a train operating at 80 km/h was within 4.5D of the lateral distance from the railway structure in the case of the condition where the temporary wall was installed.

NATE터널의 갱문 가시설 배후 균열에 따른 조치 및 보강사례

  • Kil, Ho-Un;Kim, Jin-Hong;Yoo, Jai-Sung;Cha, Bok-Nam
    • 기술발표회
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    • s.2006
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    • pp.342-355
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    • 2006
  • The Tunnel portal is designed on temporary support system which is composed by 28m height H-Pile method and Ground Anchor method. The tunnel has excavated about 30m from the portal, but some deformation is found on the surface ground just above the tunnel face. It was investigated very carefully to find out the causes of deformation. By the observation and study, two main causes of deformation are found out. The one is earth pressure increase compared with classical earth pressure theory. That was due to the direction of ground rock mass's discontinuities. It causes the increase of earth pressure that are activated by the direction of discontinuity. The other one is that present design method neglect the transferred force by removal of temporary support members and ground anchor within the tunnel contour line as the tunnel excavation proceeds As the result of removals of the member and anchor, some force transferred from removed systems to remaining supporting systems. In designing the portal support systems, lt must be considered the discontiunity of ground mass and the transfered force due to excation.

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