• Title/Summary/Keyword: Field pull-out test

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Field Pull-out Test and Numerical Analysis for Multi-rebar Nail (다철근 네일의 현장인발시험 및 수치해석)

  • Jeon, Sang-Soo;Kim, Doo-Seop;Jang, Yang-Won
    • Journal of the Korean Geotechnical Society
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    • v.24 no.8
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    • pp.43-52
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    • 2008
  • In this study, the verification test and creep test for both a single-rebar nail and a multi-rebar nail are carried out to investigate a tensile strength for both nails. The adhesion effects between a rebar and a cement grout, a mobilized frictional force induced by pull-out load, and load transfer characteristics are examined. The results obtained from the field pull-out tests and from the numerical analysis using $FLAC^{2D}$ which is one of the programs developed based on the finite difference method are analyzed and compared for a single-rebar nail and a multi-rebar nail. The field pull-out test results for a multi-rebar nail relative to a single-rebar nail show that a tensile failure load is relatively large and the pull-out loads are well transferred to the ground in deep depth.

A STUDY ON THE DEFORMATION OF REINFORCED EARTH USING LARGE SCALE PULL-OUT TEST (대형 Pull-out Test에 의한 보강토 지반의 변형특성에 관한 연구)

  • 이은수;이승호
    • Proceedings of the Korean Geotechical Society Conference
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    • 1993.10a
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    • pp.29-32
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    • 1993
  • Presengly reinforced earth is widely utilized for earth structure increasingly not only domestic but also in many foreign countries because of its rapidity of construction and economic merits. The study on the reinforced earth has been actively carried out and enlarged in the theoretical aspect. But it has many problems to the application of the field. In this study large scale Pull-out Test was used to analyze reinforced earthe behavior considering deformation character of reinforced earth under the similar condition to the field.

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Evaluation of Behavior Characteristics of Geosynthetic Fiber Nail System from the Field Pull-Out Tests (현장인발시험을 통한 섬유형 쏘일네일의 거동특성 평가)

  • Kim, Hong-Taek;Park, Si-Sam;Cho, Byeong-Guk;Jung, Sung-Pil
    • Proceedings of the Korean Geotechical Society Conference
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    • 2004.03b
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    • pp.342-347
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    • 2004
  • Excavation nearby the existing structures is being performed vigorously to get the greatest use of land along with fast economic growth in the downtown area. The application of soil nailing system gradually increases because of an advantage of soil nailing system adjacently constructed in the existing structures. In this study, friction resistance by pull-out is considered as main resistance except resistance formed by flexural rigidity of nail observing that resistance of flexural rigidity is about $0{\sim}15\;%$ of whole safety factor according to degree of flexural rigidity in general soil nail wall and application of geosynthetic fiber soil nailing system is evaluated through laboratory tensile strength test and field pull-out test.

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Evaluation of Behavior Characteristics of Removable Soil Nails from the Field Pull-Out Tests (현장인발시험을 통한 제거식 쏘일네일의 거동특성 평가)

  • 김홍택;강인규;이대형;정성필;박시삼
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.137-144
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    • 1999
  • Recently a removable soil nail is demanded due to problems beyond of economical and engineering purpose. In this study removable soil nails are developed and field pull-out tests are carried out 16 times in order to analysis pull-out characteristics of the removable soil nail. For the spacing and the installed position of fixed socket, the length of the soil nail, and W/C ratio of cement grout in the removable soil nail, pull-out characteristics of pull-out tests are analyzed. From the pull-out characteristics of removable soil nails, it is found that the spacing of fixed socket and W/C ratio of cement grout are important design parameters.

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Load-displacement characteristics of belled tension piles embeded in cohesionless soils (사질토지반에 근입된 벨타입 인발말뚝의 하중-변위 특성)

  • Hong, Won-Pyo;Choi, Yong-Sung;Lim, Dae-Sung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.1114-1119
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    • 2010
  • Pile foundations have been used for upholding superstructure's loads. The researches on pile foundations subjected to compressive forces or horizontal loads have been actively carried out. However, recently, pile foundations, which are subjected to pull-out forces, are getting increased. The study on the pull-out resistance of piles becomes to be important. In addition, it is expected that belled piles will be used more and more, since the belled piles are effective to resist the pull-out forces. But there is still a lack of research on pull-out resistance of belled piles. Therefore, in order to investigate the resisting effect against pull-out of belled piles which is embedded in cohesionless soil. a series of pull-out test is performed on belled piles in field. Especially, the relation between load and displacement is analyzed through the pull-out test.

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Field Pull-out Test and 3-D FEM Analysis for Steel Pipe Nailing Installed Foldable Wedge (접이식 웨지 장착 강관네일의 현장 인발시험 및 3차원 유한요소해석)

  • Kwon, Kyo-Keun;Choi, Bong-Hyuck
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6C
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    • pp.313-319
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    • 2009
  • In this study, field pull-out test and 3-D FEM analysis have been performed for examining and reflecting the behavior of steel pipe nailing installed foldable wedge. Field pull-out test was performed under various conditions. As a result, the steel pipe nailing installed foldable wedge has an effect of pull-out resistance increased about 30% in comparison with non-wedge type steel pipe nailing. Through back analysis in 3-D FEM for behavior of non-wedge type steel pipe nailing, friction characteristics between nail to soil was analyzed and obtained first consistent with field pull-out behavior. Then, the frictional characteristic was used for analyzing the behavior of the steel pipe nailing installed foldable wedge. The result was compared with the test results. Consequently, friction coefficient (${\mu}$) of about 1.2 between grout to soil leads to good agreement with analysis results and test results. And a limited pull-out resistance, $$T_L{\sim_=}32$$ tonf is similar to field pull-out test result which is improved about 33% in comparison with non-wedge type steel pipe nailing's $$T_L{\sim_=}24$$ tonf.

Proposal of Concrete Pull Off Bond Strength Measurement Method for Bridge Deck Overlay (교면 덧씌우기 콘크리트의 인발부착강도(引拔附着强度) 시험법(試驗法) 제안(提案))

  • Kim, Seong-Hwan;Kim, Dong-Ho;Kim, Hyun-Oh;Lee, Bong-Hak
    • Journal of Industrial Technology
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    • v.23 no.A
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    • pp.149-156
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    • 2003
  • The development and maintenance of a sound bond are essential requirements of concrete repair and replacement. The bond property of a overlay to its substrate concrete during the lifetime is one of the most important performance requirements which should be quantified. A standard or a verified bond strength measurement method is required at field for screening, selecting materials and quality control for overlay or repair materials, but no test method has been adopted as a standard. In this study, a concrete pull off bond strength measurement method for field application is proposed and evaluated. This study compares the splitting tensile test, slant shear test, nipple pipe direct tensile test, flexural adhesion test, briquette tensile test, jumbo nail pull-out test and core pull-off test with their test procedures. From these comparison and investigation, core pull-off test is selected as a main topic of this study because of it's suitability for in situ testing, simplicities in field application and clearness at interface boundary condition. Thus, the proposed core pull off test is evaluated to be the most appropriate method for field application in a simple manner. The fracture surface and fracture mode could be easily determined by visual observation of failure surface of the field specimen. The core pull off test was found to be sensitive to surface condition and latex contents at latex modified concrete.

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Deformation Characteristics of the Pressurized Grouting Soil Nailing Systems from the Field Pull-out Tests (현장인발시험을 통한 가압 그라우팅 쏘일네일의 변형특성)

  • Chun, Byungsik;Park, Joosuck;Park, Sisam;Jung, Jongju;Kong, Jinyoung
    • Journal of the Korean GEO-environmental Society
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    • v.9 no.2
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    • pp.61-65
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    • 2008
  • In this study, a newly modified soil nailing technology named as the PGSN (Pressurized Grouting Soil Nailing) system is proposed. Effects of various factors related to the design of the pressurized grouting soil nailing system, such as the length of re-bars and type of reinforcement materials, were examined throughout a series of the displacement-controlled field pull-out tests. 9 displacement-controlled field pull-out tests were performed and the ratio of injected grout volume to grout hole volume were also evaluated based on the measurements. In addition, short-term characteristics of pull-out deformations of the newly proposed PGSN system were analyzed and compared with those of the ordinary soil nailing system by carrying out field pull-out tests. The test results were shown that the displacements of pressurized grouting soil nailing system were decreased 30~36% in comparison with using gravity grouting soil nailing system by the pressurized effect. The displacements of steel tube were diminished 31~32% comparison with using deformed bar by the reinforcement type change from the field pull-out tests.

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Estimation of Pull-out Behavior for Steel Pile Nailing installed Foldable Wedge by Field Measurement (현장계측에 의한 접이식 웨지 장착 강관네일의 인발거동 평가)

  • Kwon, Kyo-Keun;Choi, Bong-Hyuck;Kim, Kyung-Min
    • Journal of the Korean Geosynthetics Society
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    • v.8 no.4
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    • pp.19-25
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    • 2009
  • In this study, field pull-out tests were performed for steel pipe nailing installed foldable wedge and non-wedge type steel pipe nailing under the same test conditions. This is to evaluate pull-out resistance improvement effect of steel pipe nailing installed foldable wedge. Evaluating for field pull-out characteristics of steel pipe nailing installed foldable wedge was performed through analysis of ultimate pull-out resistance ($T_L$), ultimate unit skin friction ($q_s$, $u_{max}$), tensile normal stiffness ($K_{\beta}$), tension of nail. As a result, the steel pipe nailing installed foldable wedge have an effect of pull-out resistance increased about 30% in comparison with non-wedge type steel pipe nailing.

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A Study on the Behavioral Characteristics of a Circular Foundation Dominated by Pull-Out Load through Field Test (현장시험을 통한 인발하중이 지배적인 원형기초의 거동 특성 연구)

  • Shin, Kyung-Ha;Lee, Seung-Ho;Lee, Dong-hyuk;Park, Du-hee
    • Journal of the Korean Geosynthetics Society
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    • v.20 no.4
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    • pp.53-62
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    • 2021
  • For the rational application of LRFD, which is actively applied in Korea, for the study of the pull-out load and the horizontal load, which are insufficient examples, a circular foundation based on the transmission tower foundation, which is a socially important structure, through field tests in single and mixed layer. Factors that can affect the design were studied by analyzing the resistance of each stratum to pull-out and horizontal loads.