• Title/Summary/Keyword: Anchor force

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Development of the Braket for External Prestressing Method in Slab Bridge (슬래브교 외부 강선 보강용 정착구 개발)

  • 한만엽;이상열
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.93-98
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    • 2001
  • This study is to develop the end anchorage of external steel reinforcement of RC slab bridges. External prestress method using the existing steel is that When the anchorage is installed in slab end, a plenty of anchor bolts were required because the only tangential stress of anchor bolt received a tendon force. Then, for this reason, the wide end anchorage was required and the shape was complicate. But this reinforcement method using method that inserts anchor key at concrete surface cut a groove gets big internal force comparing to the anchorage using existing anchor bolt. Furthermore, the number of anchor bolt for installing apparently will be reduced, and the operation will be convenient because a small anchorage of a simple shape will be received a great tendon force

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Development of the Bracket for External Prestressing Method for Slab Bridge (콘크리트 교량의 외부강선 보강을 위한 앵커키 정착장치의 개발 연구)

  • 한만엽;이상열
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.1009-1014
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    • 2001
  • This study is to develop the end anchorage of external steel reinforcement of RC slab bridges. External prestress method using the existing steel is that When the anchorage is installed in slab end, a plenty of anchor bolts were required because the only tangential stress of anchor bolt received a tendon force. Then, for this reason, the wide end anchorage was required and the shape was complicate. But this reinforcement method using method that inserts anchor key at concrete surface cut a groove gets big internal force comparing to the anchorage using existing anchor bolt. Furthermore, the number of anchor bolt for installing apparently will be reduced, and the operation will be convenient because a small anchorage of a simple shape will be received a great tendon force.

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Study on grout-free smart ground anchor using electromagnetic induction

  • Hyun-Seok Lee;Jong-Kyu Park;Jung-Tae Kim
    • Structural Engineering and Mechanics
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    • v.90 no.6
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    • pp.531-542
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    • 2024
  • This study proposes a ground anchor using electromagnetic induction and utilizes an extended structure using hinges and links and mounting and sensing using electromagnets. The aim is to secure the anchor force, excluding grout, and to secure various sensing capabilities, including ground behavior. We propose a design based on the drilling diameter of 150 mm, and the materials used were STS304 and Aluminum 6061-T6. Computerized analysis was performed to confirm structural safety and functional implementation. The pull-out experiment was conducted by simulating the bedrock environment on a model earthwork as an experiment to check whether anchor force was generated by the insertion and tension of the anchor. The environmental pollution of grout, the difficulty of removing strands, and the inability to check whether the anchor is seated, which were pointed out as disadvantages of the existing ground anchor, were solved. Therefore, this study suggest that it can be effectively utilized as a secure and monitored anchoring solution in eco-friendly construction practices, including the installation of landslide prevention barriers.

A Case Study on CGP Anchor of Open-Cuts in Soft Ground (연약지반에서 CGP-앵커의 시공사례연구)

  • 천병식;양형칠;박신영
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.621-628
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    • 2002
  • Compaction Grouting Pack (CGP) Anchor which is composite anchor of bearing plus friction-type was chosen and executed for the open-cuts in soft ground. This paper presents an analysis of data from tests on composite-anchor by jacking force. The properties of composite-anchor was presented to be as follows , the maximum plastic displacement was 60 mm in abandoned coal fill deposit, the shear stress($\tau$) is expressed as $\tau$ = (equation omitted) kg/$\textrm{cm}^2$ in clayey silt.

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Finite Element Analysis on Impedance Parameters of Anchor Plate of Structural Cables Under Cable Force Changes (구조용 케이블의 장력 변화에 따른 정착부의 임피던스 특성에 대한 유한요소해석)

  • Nguyen, Khac-Duy;Park, Jae-Hyung;Hong, Dong-Soo;Lee, Ju-Won;Kim, Jeong-Tae;Na, Won-Bae
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2010.04a
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    • pp.783-786
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    • 2010
  • This paper presents a finite element analysis on impedance parameters of anchor plates of structural cables under the change in cable forces. To achieve the objective, four approaches are implemented as follows: Firstly, theoretical background of electro-mechanical impedance is described. Secondly, anchor plates of structural cables are selected to experimentally examine the relationship between impedance parameters and cable force changes. Thirdly, finite element analysis is performed to verify the experimental results. Fourthly, a comparison between the experimental and numerical analysis on impedance parameters of anchor plate of structural cables under cable force changes is carried out.

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Evaluation of Loss of Prestress Force of Tensile Anchor by Long Term Measurement (장기계측을 통한 인장형 앵커의 인장력 손실 평가)

  • Lee, Bongjik;Lee, Jongkyu
    • Journal of the Korean GEO-environmental Society
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    • v.16 no.10
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    • pp.15-22
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    • 2015
  • In this study, to evaluate the long-term behavior characteristics and the loss of prestress force, the long-term measurement of the tensile anchors in the actual construction was performed and the results were analyzed comparing with the existing estimation. As the reinforcement member used for the purpose of slope stability or uplift-resisting of the permanent structure, etc, the permanent anchor should maintain the functions during the performance period of the structure differently from the temporary anchor. However, as the time passes by, since the relaxation and the creep of the anchor occur constantly, the management for the loss of tensile force is essential to perform the functions stably. So far, the loss of the tensile force has been estimated according to the reduction of the prestress using elasticity theory and using the relaxation value according to the type of tension member and the test using the long-term measurement is limited. Therefore, in this study, the site condition and the ground were investigated for the tensile anchor in the actual construction and the long-term measurement results more than 500 days was analyzed by installing the loadcell, inclinometer and the groundwater level gauge. In addition, the long-term behavior characteristics were evaluated by comparing the disposition of the measured earth retaining wall and the tension force loss of the anchor with the existing interpretation results. In the evaluation results, the most of the tension force loss occurs within 90 days and the loss was measured less than the estimated values.

Structural Analysis of a Cable Anchor System for a Cable-Stayed Bridge over the Sea (해상 사장교의 Pipe형 케이블 정착구에 관한 구조해석)

  • KONG BYUNG-SEUNC;HONG NAMSEEG
    • Journal of Ocean Engineering and Technology
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    • v.19 no.5 s.66
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    • pp.34-42
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    • 2005
  • The cable connection zone of the cable-stayed bridge transfers deal-load, live-load, and second-load to the cables on the structural joint zone of the cables and the main girders are the most critical parts in which big cable tensile forces are generated by those loads. Therefore, it is necessary to thoroughly check the main girder, structurally to secure the required stability. Because of the heavy tensile force of cables linked in the connection zone of the cable-stayed bridge, locally concentrated stress, as well as the dispersion of stress, occurs in the structurally contacted point of cable and main girder thus, we need to make a thorough investigation through a detailed structural analysis. Directly delivering the tensile force to the connection zone of the cable, the consequently big effect in the tensile force fluctuation caused by the live-load will make it necessary to review the fatigue strength. As the connection zone of the cable is designed to resist the tensile force of the cable, which is applied to a connecting section as a concentrated force, thick plates are used. These plates are frequently made of welded structure, thus, the investigation of the welding workability is inevitable.

Characteristics of Pullout Behavior of Soil Improvement(SI) Anchor (지반개량(SI)앵커의 인발거동특성)

  • 임종철;홍석우;송무효;강낙안
    • Geotechnical Engineering
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    • v.14 no.6
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    • pp.139-151
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    • 1998
  • SI anchor means the soil improvement anchor. The ground for supporting anchor is improved by JSP, and as a result, SI anchor body has about 80cm in diameter. SI anchor shows high pullout resistance by the frictional force between anchor body and ground, and the bearing capacity of anchor body. Especially the frictional force increases very much with increasing diameter of anchor body improved by JBP. In this study, model and field tests are made to analyse the mechanism of pullout resistance of SI anchor. Through model tests for the SI anchor in air dried sandy ground, strain fields of ground around SI anchor surface are analysed by a photo analysis method using the latex membrane on the wall of soil tank. The results of field tests are analysed by the strains measured by 10 strain gages attached on the inner wall of specially designed PVC pipe embedded in anchor body, and the strains of anchor body are also measured in the model tests.

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Investigation on seismic behavior of combined retaining structure with different rock shapes

  • Lin, Yu-liang;Zhao, Lian-heng;Yang, T.Y.;Yang, Guo-lin;Chen, Xiao-bin
    • Structural Engineering and Mechanics
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    • v.73 no.5
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    • pp.599-612
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    • 2020
  • A combination of a gravity wall and an anchor beam is widely used to support the high soil deposit on rock mass. In this study, two groups of shaking table test were performed to investigate the responses of such combined retaining structure, where the rock masses were shaped with a flat surface and a curved surface, respectively. Meanwhile, the dynamic numerical analysis was carried out for a comparison or an extensive study. The results were studied and compared between the combined retaining structures with different shaped rock masses with regard to the acceleration response, the earth pressure response, and the axial anchor force. The acceleration response is not significantly influenced by the surface shape of rock mass. The earth pressure response on the combined retaining structure with a flat rock surface is more intensive than the one with a curved rock surface. The anchor force is significantly enlarged by seismic excitation with a main earthquake-induced increment at the first intensive pulse of Wenchuan motion. The value of anchor force in the combined retaining structure with a flat rock surface is generally larger than the one with a curved rock surface. Generally, the combined retaining structure with a curved rock surface presents a better seismic performance.

Development of Visual Confirmation Device for Anchor Tensile Force (앵커 긴장력 상시확인을 위한 육안확인장치 개발)

  • Yoon, Hwan Hee;Lee, Yong Joo;Oh, Dong Wook;Kim, Dong Hyun;Jung, Hyuk Sang
    • Tunnel and Underground Space
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    • v.28 no.5
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    • pp.493-511
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    • 2018
  • This paper deals with visual confirmation device for tensile force verification in order to cope with tensile force loss of ground anchor. Ground anchors are constructed to ensure the stability of social infrastructure facilities, but continuous loss of tensile force is seriously concerned about safety of the facilities. This requires the maintenance of the anchors, but the current measuring of residual tensile force is done by sampling, taking into account economic aspects, which limits precision. In this paper, conducted a conceptual design, tensile experiment, and field test for the purpose of developing an anchor tensile force visual device to check the tensile force of the anchors.