• Title/Summary/Keyword: bearing anchor

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Pullout Behavior Characteristics of Enlarged Cylinder Type Anchor Using Numerical Analysis (수치해석을 이용한 확공형 앵커의 인발거동 특성)

  • Moon, Joon-Shik;Lee, Min-Joo
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.113-118
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    • 2017
  • Numerical analysis was carried out using a finite element analysis program to analyze the behavior characteristics of enlarged cylinder type anchor. It was found that the ultimate resistance of enlarged cylinder type anchor increases with the enlargement angle from numerical analysis for various enlargement angle cases. In the case of $30-60^{\circ}$ of enlargement angle, the deformation and stress distribution characteristics in anchor are similar regardless of enlargement angle. However, when the same tensile force is applied, there is a difference in the degree of frictional resistance because of difference of displacement of top of grouting zone. Also, it was found that the maximum compressive force and tensile force were generated at the cone of the upper portion of the grouting zone, and tensile fracture of the upper grouting portion is likely to occur.

Bearing Reinforcing Effect of Concrete Block with a Round End according to the Application of Aluminum Stiffener (알루미늄 보강재 적용에 따른 원형 단부 콘크리트 블록의 지압 보강 효과)

  • Seok Hyeon Jeon;Tae-Yun Kwon;Jin-Hee Ahn
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.3
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    • pp.38-46
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    • 2023
  • In this study, a bearing test was performed and analytically evaluated to evaluate the bearing performance according to the application of the aluminum stiffener in round-end concrete. In the bearing strength test, the change in bearing performance due to the aluminum stiffener using the aluminum form for manufacturing concrete with round-end, and the steel anchor bolts for member movement and assembly was confirmed. The FE analysis model was identically configured to the experimental conditions, and the result was compared with the experiment. Also, the crack patterns and stress behavior were confirmed. In addition, the effect of strength change of the aluminum stiffener on the round-end concrete was also evaluated analytically. The bearing strength of the round-end concrete increased by about 20% due to the aluminum stiffener, and it was confirmed that the steel anchor bolt did not affect the bearing strength. The maximum load and crack patterns shown as a result of FE analysis were similar to those of the experiment. As a result of FE analysis according to the strength change of the aluminum stiffener, the maximum load change according to the increase and decrease of the strength of the aluminum stiffener by 10% and 20% was evaluated to have no significant effect at a maximum of about 4% compared to before the strength change.

Arthroscopic Reduction of Subluxed Medial Meniscus using Suture Anchor for Restoration of Hoop Stress - Technical Note - (버팀테응력 회복을 위한 아탈구된 내측 반월상 연골의 Suture anchor를 이용한 정복술 - 술기 보고 -)

  • Kim, Jaw-Hwa;Lee, Yoon-Seok;Kim, Chul;Han, Seung-Chul
    • Journal of the Korean Arthroscopy Society
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    • v.13 no.3
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    • pp.280-284
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    • 2009
  • Purpose: The authors introduce a new technique of arthroscopic reduction of subluxed medial meniscus using suture anchor for the restoration of hoop stress. Operative Technique: Anterolateral, anteromedial, and medial midpatellar arthroscopic portal are used. Arthroscope was inserted through anterolateral portal. Through the scope, we confirmed subluxation of medial meniscus. Transection of menisci including radial and root tear were excluded. We released the anterior horn of medial meniscus through anteromedial and burred the future insertion site of suture anchor. After inserting suture anchor through medial midpatellar portal, we used 90 degree suture hook and no.2 Nylon to retrieve the suture of inserted anchor. We tied the suture by sliding knot-tying method. Weight bearing was limited for 6 weeks postoperatively. Conclusion: Arthroscopic retightening of medial meniscus is less invasive, conserving and progressed method for subluxed meniscus.

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A Study on the Design of Special Circular Plate Anchorage for Post-tension (원형 정착판을 사용한 포스트텐션 특수정착구의 설계에 관한 연구)

  • Choi, Kyu-Hyung;Lho, Byeong-Cheol;Lim, Jung-Hoon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.6
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    • pp.73-83
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    • 2016
  • Bearing stress near anchor plates is usually very high due to prestressing force in anchorage zone of concrete structure used post-tensioned prestressed method. In order to effective utilization of cross section and crack control, appropriate size of anchorage plates should be used to prevent crack initiation and failure of concrete structures eventually. This study aims to suggest equation for effective area of bearing plate of rectangle type and circular type by Highway Bridge Design Specification and PTI etc. A shape factor according to bearing plate shape is suggested based on numerical analysis, and it can be used suitability for design of special anchorage plate dimension.

The Study of Rehabilitation for Transverse Movement of Superstructure (교량 상부구조 횡방향 이동에 대한 보강방안 고찰)

  • Shin, Jae-In;Lee, Beyong-Ju;Park, Chang-Ho;Seo, Sang-Gil
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.129-132
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    • 2008
  • All bearing device should be examined to determine that they are functioning properly. Small changes in other portions of the structure, such as pier or abutment settlement, may be reflected in the bearings. Bearings should be checked to see that they can move freely and are clear of all foreign material. Shoes should be in proper position relative to the temperature at the time of the inspection. Check anchor bolts for any damage and to see that nuts are secure. See that anchor bolt nuts are properly set on the expansion bearings to allow normal movement. In this paper, rehabilitation method for damaged bearings is proposed and damage example of the skewed bridge is illustrated

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Development of the Prefabricated Anchoring Device for External Strengthening (외부 강선 보강용 조립식 정착장치 개발 연구)

  • Han Man-Yop;Lee Sang-Wook
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.461-464
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    • 2004
  • External prestressing method is the most papular method to strengthen concrete structures. The key parts of external prestressing method is an anchoring device which holds the prestressing cables. The most popular anchoring devices is an end bearing type, which has to be welded at site to assamble the anchor. The welding at site has a significant Quality problem. In this paper, new anchoring system has been developed, which needs no site welding. A design method for the new anchor has been proposed and developed to optimize the anchoring system. The developed anchors are very efficient, small, and compact, which have two types, one for abutment section and the other one for pier section. The anchors are expected to be used very widely, because of its convinience.

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A Study on Stability Evaluation of the Nail-Anchor Mixed Support System

  • Kim, Hong-Taek;Cho, Yong-Kwon;Yoo, Han-Kyu
    • Journal of the Korean Geotechnical Society
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    • v.15 no.3
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    • pp.41-70
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    • 1999
  • The benefits of utilizing internal reinforced members, such as soil nails and ground anchors, in maintaining stable excavations and slopes have been known among geotechnical engineers to be very effective. Occasionally, however, both soil nails and ground anchors are simultaneously used in one excavation site. In the present study, a method of limit equilibrium stability analysis of the excavation zone reinforced with the vertically or horizontally mixed nail-anchor system is proposed to evaluate the global safety factor with respect to a sliding failure. The postulated failure wedges are determined based on the results of the $FLAC^{2D}\; 및\; FLAC^{3D}$ program analyses. This study also deals with a determination of the required thickness of the shotcrete facing. An excessive facing thickness may be required due to both the stress concentration and the relative displacement at the interface zone between the soil nailing system and the ground anchor system. A simple finite element method of analysis is presented to estimate the corresponding relative displacement at the interface zone between two different support systems. As an efficient resolution to reduce the facing thickness, the modified bearing plate system is also proposed. Finally with various analysis related to the effects of design parameters, the predicted displacements are compared with the results of the $FLAC^{2D}$ program analyses.

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Evaluation of Impact Resistance of Interior Stone Walls Constructed on the ALC Block Wall (ALC 블록 벽체에 시공한 석재 아트월의 내충격성 평가)

  • Ko, Bong-Cheon;Lee, Duck-ju;Kim, Hyun;Chol, Soo-Kyung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2019.05a
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    • pp.10-11
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    • 2019
  • Interior stone walls are using commonly in non-bearing lightweight walls of apartments. The stones of interior wall were two types, one is a granite stone, another is a marble stone. Granite stone is attached by the epoxy adhesive and marble stone is attached by dedicated anchor and fastener. The impact resistance test was carried out interior stone walls in accordance with KS F 2613. The test methods included the impact resistance tests by each of soft impact body and hard impact body. The results of the test have proved that interior stone walls can withstand the soft impact bodies and hard impact bodies that are likely to happen in everyday life.

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A Study on Pylon Cable Anchor System in Cable-Stayed Railway Bridge (철도용 사장교의 주탑 케이블 정착부에 관한 연구)

  • Han, Sung-Gwan;Gong, Byung-Seung
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.565-580
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    • 2006
  • Set in constant increase and period current of lively technical development of railroad use and construction of cable stayed bridge railway bridge, one of bridge form of most suitable that think side police officer and the material enemy of bridge that use long rail, is increasing laying stress on the foreign countries. Main tower fixing department of this cable stayed bridge is consisted of main tower flange that support bearing plate, bay ring plate bearing plate, support end rib and diaphragm etc, as stress transmission mechanic that tensility of cable socket into normal force of main tower, and is used this time. These structural elements is very complex the structure and direction of load delivered from socket specially calbe particularly be different, and need FEM analysis that use Thick Shell element for suitable arrangement of mutual stress flowing grasping and absence that follow hereupon because all of the each support plate angle that suport this differ.

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Studies on the Development of Bearing Capacity Reinforcement for the Foundation of Soil (기초지반의 지지력보강공법에 관한 연구)

  • 유동환;최예환;유연택
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.30 no.1
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    • pp.38-49
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    • 1988
  • This paper presented as follows results of laboratory model tests with various shaped footings on soil bed reinforced with the strips on the base of behaviour of soil structure according to the loads and triaxial test results reinforced with geotextiles. Their parameters studied were the effects on the bearing capacity of a footing of the first layer of reinforcement, horizontal and vertical spacing of layers, number of layers, tensile strength of reinforcement and iclination load to the vertical 1.Depending on the strip arrangement, ultimate bearing capacity values could be more improved than urreinforced soil and the failure of soil was that the soil structure was transfered from the macrospace to microspase and its arrangement, from edge to edge to face to face. 2.The reinforcement was produced the reinforcing effects due to controlling the value of factor of one and permeable reinforcement was never a barrier of drainage condition. 3.Strength ratio was decreased as a linear shape according to increment of saturation degree of soil used even though at the lower strength ratio, the value of M-factor was rot influenced on the strength ratio but impermeable reinforcement decreased the strength of bearing capacity. 4.Ultimate bearing capacity under the plane-strain condition was appeared a little larger than triaxial or the other theoretical formulars and the circular footing more effective. 5.The maximum reinforcing effects were obtained at U I B=o.5, B / B=3 and N=3, when over that limit only acting as a anchor, and same strength of fabric appeared larger reinforcing effects compared to the thinner one. 6.As the LDR increased, more and more BCR occurred and there was appeared a block action below Z / B=O.5, but over the value, decrement of BCR was shown linear relation, and no effects above one. 7.The coefficient of the inclination was shown of minimum at the three layers of fabrics, but the value of H / B related to the ultimate load was decreased as increment of inclination degree, even though over the value of 4.5 there wasn't expected to the reinforcing effects As a consequence of the effects on load inclination, the degree of inclination of 15 per cent was decreased the bearing capacity of 70 per cent but irnproved the effects of 45 per cent through the insertion of geotextile.

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