• 제목/요약/키워드: 보강공법

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A Case Study of Extra Reinforcement by Road Extension work on Existing Cut Slope Reinforced with Counterweight Fill and Stabilizing Piles (압성토 및 억지말뚝으로 보강된 도로의 확장공사로 인한 추가 보강사례 연구)

  • Park, Jeong-Yong;Kim, Woo-Seong;Kim, Jae-Kyoung;Yang, Tae-Sun;Na, Kyung-Joon
    • Journal of Korean Society of societal Security
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    • v.1 no.2
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    • pp.67-72
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    • 2008
  • To confirm the stability of a cut slope in the road extension construction site, several investigations were carried out and countermeasures of slope was studied. This paper describes a study of design case of extra reinforcement on existing cut slope reinforced by preloading and piles in roads. To investigate the effect of stabilizing piles installed in a cut slope, an instrumentation system also designed, was. As a result that the stabilizing file and earth anchor are considered as the extra reinforcement, both stabilizing pile and earth anchor guarantee the stability of cut slope. However, stabilizing pile is selected in aspects of economy and continuity to the existing cut slop reinforcement including counterweight fill and stabilizing piles.

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Study on Arching Characteristics of a Grand-Section Tunnel with Pre-Steel-Rib Nail Reinforcement (대단면 터널의 선지보네일 보강에 따른 아칭특성 연구)

  • Seo, Donghyun;Cheun, Seungyul;Lee, Seungho
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.6
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    • pp.79-88
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    • 2009
  • In this study, it was studied on arching characteristics of a grand section tunnel with pre-steel-rib nail reinforcement. In this study, we examine the adaptation of tunnel plan and the case which is based on the strengthening method for preexistence tunnel and other pre-steel-rib nail while the upper part of cover depth is low or soil condition is bad. When the pre-steel-rib nail as new technology and method reinforces the foundation placed of grand section tunnel, it is much better in strengthening effect, safety and effectiveness than the conventional one. After investigation about the plan pre-steel-rib nail method, construction case and calibration data, it was confirmed and examined about the upper part of tunnel for strengthening the pre-steel-rib nail thereby arching characteristics of grand section tunnel using MIDAS/GTS finite element program. Moreover we present the method that could upgrade the accurate installation interval and adaptation method for strengthening effect to adapt the pre-steel-rib nail method in a foundation placed over a tunnel.

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Suggestion of Flexural Strengthening Ratio of NSM Strengthened Concrete Railroad Bridge based on Probability and Reliability (확률.신뢰도에 기초한 표면매립보강(NSM) 콘크리트 철도교의 휨보강비 산정)

  • Oh, Hong-Seob;Sim, Jong-Sung;Ju, Min-Kwan;Lee, Ki-Hong;Park, Ji-Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.121-124
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    • 2008
  • The purpose of this study is to evaluate the critical strengthening ratio of concrete railroad bridge strengthened with NSM using CFRP plate. The railroad bridge is usually under vibration and impact in service state. Therefore, it is important that the effective strengthening performance must be exhibited under the service loading is acted. To widely apply the NSM method for the concrete railroad bridge in field, it needs that reasonable strengthening parameter such as strengthening ratio has to be investigated and evaluated when the strengthening design is conducted. In this study, to suggest more reasonable strengthening ratio, material and geometrical uncertainty was considered and applied by Monte Carlo Simulation (MSC) technique. Lastly, the critical strengthening ratio of concrete railroad bridge strengthened with NSM using CFRP plate was evaluated by using the limit state function with the target reliability index.

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Evaluation of Reinforcement Efficiency and Applicability Using a Reinforcement Method for Liquefiable Ground (액상화 발생 지반에 대한 보강공법 별 보강 효과 및 적용성 분석)

  • Yoo, Mintaek ;Han, Jin-Tae;Park, Youngjun ;Kim, Seok-Jung
    • Journal of the Korean Geotechnical Society
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    • v.39 no.5
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    • pp.41-50
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    • 2023
  • This study reviewed the liquefaction reinforcement and ground reinforcement methods widely used domestically and abroad through construction method characteristics and analyzed the economic feasibility and reinforcement efficiency of each reinforcement method. The analysis results were used to evaluate the applicability of the appropriate reinforcement method for the liquefaction reinforcement of new and existing structures. As a result of evaluating the applicability of the reinforcement method based on the economic feasibility and reinforcement effect of each reinforcement method, the compaction method, which secures the construct ability by applying large equipment, is advantageous when reinforcing a new structure, and the low-fluidity mortar injection method (C.G.S method) and the high-pressure injection method (J.S.P method) are considered appropriate in the existing structure.

Development of Countermeasure Expert System for Tunneling Failure (터널 붕락특성과 시공 중 보강공법 선정방법 개발)

  • 김창용;박치현;배규진;홍성완;오명렬
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2000.09a
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    • pp.171-181
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    • 2000
  • Many Studies of tunnel and tunnelling safety have been developed continuously based on the increasing social interests in underground space since 1990's in Korea. Because the growth of population in metropolitan has been accelerated at a faster pace than the development of the cities, underground facilities have been created as a great extent in view of less land space available. In this study, a lot of types of tunnel failure were surveyed and the detail causes were studied after many cases of tunnel failure were collected. There were suggested brief countermeasure of tunnel failure through case study. An expert system was developed to predict the safety of tunnel and choose proper tunnel reinforcement system using fuzzy quantification theory and fuzzy inference rule based on tunnel information database. The comparison result between the predicted reinforcement system level and measured ones was very similar. In-situ data were obtained in three tunnel sites including subway tunnel under Han river. This system will be very helpful to make the most of in-situ data and suggest proper applicability of tunnel reinforcement system developing more resonable tunnel support method from dependance of some experienced experts for the absent of guide.

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Evaluation of Reinforcement Effects According to Reinforcement Type and Grouting Method (지반보강재의 형상과 그라우팅 방법에 따른 보강효과 평가)

  • Park, Jongseo;Kim, Taeyeon;Lee, Bongjik
    • Journal of the Korean GEO-environmental Society
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    • v.20 no.8
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    • pp.13-20
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    • 2019
  • In order to ground reinforcement, the chemical grouting, the anchor, the soil nailing system, the micropile, etc. can be mentioned by the methods widely used in domestic. The above ground reinforcement methods are developed by various methods depending on the type of reinforcement, installation method, presence of prestress, grouting method, etc. However, in common, the strength of reinforcement, the friction force of grout and reinforcement and the friction force of grout and ground are the main design variables. Therefore, the optimized ground reinforcement is a material with a high tensile strength of the reinforcement itself, the friction force between the reinforcement and the grout is high, and the application of an optimal grouting method is necessary to improve the friction force between the grout and the ground. In this study, a total of 20 model tests were conducted to analyze the reinforcement effects according to the shape of the reinforcement and the grouting method. As a result of the test, As a result of the experiment, it is judged that the reinforcing effect is superior to the perforated + wing type reinforcement and post grouting method.

Application Evaluation of Countermeasure Method using Analysis of Failure Causes for Reinforced Slope (보강된 비탈면의 파괴원인 분석 및 대책공법의 적용성 평가)

  • Han, Jung-Geun;Hong, Ki-Kwon;Lee, Jong-Young;Jung, Sun-Kuk
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.1
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    • pp.9-18
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    • 2011
  • This paper described that the failure causes of reinforced slope are analyzed based on the effect of geological and rainfall. The analysis result confirmed that the rainfall has effects on the stability of reinforced slope. Therefore, it was applied to the dewatering method using collector well for slope stabilized, and then the analysis of seepage and slope stability were conducted on slope with the applied method. The results of seepage analysis are corresponded with failure cause by rainfall and the results of slope stability, which is applied to dewatering method, are satisfied with safety factor criterion. Therefore, it confirmed that the dewatering method using collector could be possible to apply in field and reasonable method for slope stabilized during heavy rainfall.

Slope Reinforcement Method by Simultaneous Injection Technique using MPS(Multi Packer System) (멀티패커를 이용한 동시다단주입 MPS 사면보강공법)

  • Woo, Sang-Back;Jung, Hee-Seok;Lee, Jae-Dug
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.109-116
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    • 2010
  • 일반적으로 사용되는 비탈면 보강공법은 중력식 혹은 가압식 네일링, 앵커 등이 있다. 이들 공법은 주입재 주입압력이 중력식무압 혹은 낮은 압력의 가압에 의한 것으로서, 실제로 단층파쇄대, 붕적층, 이완 및 절리 등이 발달한 지반에서는 일정압력의 가압주입에 의한 지반보강과 보강재에 의한 네일링 효과를 동시에 기대해야 한다. 본 사례에서는 가압주입의 효과를 높이기 위해 보강구간을 일정한 간격으로 나누고 구간별 별도의 주입펌프를 연결하여 보강길이 전구간을 동시에 주입하는 멀티패커시스템(MPS)공법을 소개하고자 한다.

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A Study for Structural Behavior of R./C beams Strengthened with New Bonding Methods (보강재의 변형 부착에 따른 보의 구조적 거동)

  • 한만엽;송병표
    • Magazine of the Korea Concrete Institute
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    • v.10 no.3
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    • pp.197-208
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    • 1998
  • 최근들어 손상된 실구조물의 보강공법들이 적용,발전되어왔다. 가장 보편적으로 사용된공법이 강판과 탄소섬유를 이용한 공법이지만, 이론적인 배경과 적용기술이 아직은 정립되어었지 않은 상태이다. 강판보강의 경우 단부에서의 응력집중이 보강 효과를 결정짓는 가장 중요한 변수이므로, 본 연구에서는 이러한 응력집중을 완화하기 위하여 단부에 보강판과확대판을 부착하여 실험을 하였고, 탄소섬유 보강 실험에서는 다층 시공시 보강량을 조절하여 실험하였다. 실험 결과는 하중-처짐, 항복하중, 최대하중, 보강재의 전단응력의 분포와 보강재의 파괴양상을 분류하여 정리하였다. 실험을 통하여 강판 보강의 경우 본 연구에서 제안된 단부에서의 보강방법이 보강효과가 향상된 것을 확인하였고 탄소섬유 보강시에는 탄소섬유의 보강량을 조절함으로써 경제적인 설계와 시공이 가능한 것으로 나타났다.