• Title/Summary/Keyword: Bar type anchors

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Tension Test on the Bar-type Anti-buoyancy Anchors in the Weathered Rock (풍화암에 시공된 Bar Type 부력저항 앵커의 인장 시험)

  • Park, Chan-Duk;Lee, Kyu-Hwan;Ryu, Nam-Jae;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.1
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    • pp.175-181
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    • 2004
  • This study is about a section where underground water level occurs at the underground 5m depth by the excavation of the ground, as a stream is adjacent to a excavation section of High Speed Railway ${\bigcirc}{\bigcirc}$ Station construction sections and a reservoir being always full of water is located at the left side of the construction section. Therefore this test is executed for the design and construction of buoyance anchors able to permanently prevent buoyance by the underground water level at working and for the stable construction and permanent smooth maintenance of structures. In this test, bar type anchors are divided according to their length and standard to execute test-anchor test, and In spot test, 9 test-anchors test, proof test to construction process, suitability test and acceptance test are executed 4 times to 9 test-anchors by dividing anchors according to the length of permanent anchor, the outer diameter of bar and boring diameter. Standard motion characteristic centering on load transmission and break mechanism of bar-type anchors for the prevention of buoyance will be showed in the thesis.

A Study on the Pull-out Strength of Bond Type Anchors (부착식 앵커의 인발강도에 관한 연구)

  • Seo, Seong Yeon
    • Journal of Korean Society of Steel Construction
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    • v.30 no.2
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    • pp.105-114
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    • 2018
  • The use of post installed anchors with bond type has lately been increasing when it is necessary to repair, reinforce, or remodel structures. This method provides flexibility and simplicity for construction of structural members that require adhering or fixing. Meanwhile, strength evaluation of anchors with expansion type among post-installed anchors systems has nearly reached setting up stage like design code through continual experimental studies for the last ten years, but analyses or experimental studies on anchor system with bond type are not yet sufficient. Accordingly, the designers and builders of korea depend on foreign design codes since there are no exact domestic design code they could credit. In this study, the objectives are investigating the effects on pull-out strength of resin anchors embedded into plain concrete by pull-out experiment of resin anchors with variables such as anchor diameter, anchor interval, embedment depth and edge distance.

An Experimental Study on the Shear Strength of Chemical Anchors Embedded into Non Cracking Plain Concrete (비균열 무근콘크리트에 매입된 케미컬 앵커의 전단내력에 관한 실험적 연구)

  • Seo, Seong-Yeon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.4
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    • pp.21-29
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    • 2017
  • The use of post installed anchors with adhesive type has lately been increasing when it is necessary to repair, reinforce, or remodel structures. This method provides flexibility and simplicity for construction of structural members that require adhering or fixing. Meanwhile, strength evaluation of anchors with expansion type among post installed anchors systems has nearly reached setting up stage like design code through continual experimental studies for the last ten years, but analyses or experimental studies on anchor system with adhesive type are not yet sufficient. Accordingly, the designers and builders of korea depend on foreign design codes since there are no exact domestic design code they could credit. In this study, the objectives are investigating the effects on adhesive strength of anchors embedded into plain concrete by shear experiments of anchors with variables such as edge distance, anchor interval, and load direction and supplying basic data for enactment of domestic design code.

Direct Shear Test of Retrofit Anchors Using Deformed Reinforcement and Adhesive

  • Choi, Dong-Uk;Kim, Yong-Gon
    • KCI Concrete Journal
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    • v.12 no.1
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    • pp.91-99
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    • 2000
  • A new type of retrof=t anchor bolt that uses deformed reinforcing bars and a commercial adhesive was developed and then an experimental study was carried out to determine the behavior of the anchors in direct shear. The steel-to-concl몫ete interface was tested. Plain concrete slabs with about 20-MPa compressive strength were used for 23 direct shear tests performed Test variables were anchor diameters (D16, D22. and D29) and edge effect. Three different shear tests were completed: simple shear, edge shear where anchors were pulled against the concrete core, and edge shear where anchors were pushed against the concrete cover In the simple and the edge shear tests where the anchors were pulled against the core, the theoretical dowel strength determined by (equation omitted) was achieved but with relatively large displacements. The shear resistances increased with the increasing displacements. In the edge shear test where the anchors were pushrd against the cover, the peak shear strengths signif=cantly lower than the theoretical dowel strength were determined due to cracks developed in concrete when the edge distance was 80 mm. The peak strengths were about 50% of the dowel strength for Dl6 bar. and about 25% or less of the dowel strength for D22 and D29 bars. Test results revealed that the edge shear where the anchor was pushed against the cover controled.

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Lateral Load Test on the Bar-type Anti-buoyancy Anchors in the Weathered Rock (풍화암에 시공된 Bar Type 부력앵커의 수평재하시험)

  • Park, Chan-Duk;Lee, Kyu-Hwan;Ryu, Nam-Jae;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.165-174
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    • 2004
  • This study is about a horizontal load test of buoyance anchor installed in the section where underground water level happens in the depth of 5m under the ground when the ground is excavated, because the section as a excavation section of high speed railway ${\bigcirc}{\bigcirc}$ station is near a rivers and because the section always has a reservoir of full water level on the left. Therefore, in this study we will appraise the long-term stability of the structure permanently being taken buoyance by the underground water level, through the spot test of the buoyance anchor installed in the section where underground water level happens. For that, Bar Type anchor is used, which can get enough pulling-out force by a method to resist buoyance by using friction force against the ground by high strength steel rod or steel wire. Anti-buoyance anchor is installed on the bottom slab of underground structure being taken horizontal force by the braking and accelerating of high speed train. And, It is aimed to analyze and grasp the review result of stability for the horizontal force that happens at the parking and stopping of high speed train, by executing horizontal load test for the grasping of the movements characteristic of buoyance anchor.

Pullout Characteristics of MC Anchor in Shale Layer (셰일지반에 설치된 MC앵커의 인발특성)

  • Lee, Bongjik;Kim, Josoon;Lee, Jongkyu
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.1
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    • pp.53-61
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    • 2012
  • In this study, the research on MC anchor has been developed as composite type has done. MC anchor exerts bearing pressure on pre-bored hole where the end fixing device is expanded. Therefore, the uplift capacity is to be increased and it has the characteristics that the anchor body is not eliminated from the ground even if the grouting is not carried out properly. Furthermore, it reduces the loss of tension and raises the construction availability by inserting the reinforced bar as well as the anchor cable, while it can improve the long-term stability because the nail is expected to play the role when the loss of the anchor cable is occurred in a long-term. However, because the resistance mechanism of the compound anchor such as MC anchor is different from friction anchor, the estimation method of the uplift capacity by the frictional force of the ground and the grout is not proper. Particularly, in domestic cases, the problem to overestimate or underestimate the uplift capacity is expected because the design method considering the soil characteristics about the compound anchor has not been developed. Therefore, in this study, in order to evaluate the characteristics of MC anchor and a kind of compound anchor, we measured the uplift, the tension and the creep by nine anchors tests in shale ground that the fluctuation of the strength is great. In addition, we analyzed the test result comparing to the result of the general friction anchor and evaluated the characteristics of MC anchor movement to gather the results. As a result of the test, we found the effect that the uplift capacity is increased in shale ground comparing to the general friction anchor.