• Title/Summary/Keyword: anchors

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The Method for Determining the Effectiveness Factor(k value) of Concrete Expansion Anchors in accordance with ACI 355.2 (ACI 355.2에 의한 콘크리트 확장앵커의 유효계수(k값) 결정방법)

  • Lee, Byung Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2020.06a
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    • pp.151-152
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    • 2020
  • Recently, concrete expansion anchors which are a type of post-installed mechanical anchors are widely used in reinforcement concrete structures. In order to be used in the reinforced concrete structures designed in accordance with ACI 318-19 or ACI 349-13, the structural performance tests of the concrete expansion anchors should be conducted in accordance with ACI 355.2. The effectiveness factor(k) of concrete expansion anchors should be determined through the reference tests and used for the design of anchorage to concrete according to ACI 318-19 or ACI 349-13. In this study, we will look into the method for determining the effectiveness factor(k) of concrete expansion anchors and anchorage design process of concrete expansion anchors by using the effectiveness factor(k) in accordance with ACI 349-19.

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Exploring the Impact of Live Commercial Anchors on Business Performance and Survival Strategy: Focusing on Resource Configuration and Environmental Choice

  • ZHANG, Li-Jie;HUANG, Fei
    • East Asian Journal of Business Economics (EAJBE)
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    • v.10 no.4
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    • pp.1-18
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    • 2022
  • Purpose - Through the analysis and research of different characteristics and related mechanisms of live commerce anchors, this paper aimed to help live commerce anchors to strengthen their characteristic advantages, beautify the live broadcast environment, improve resource allocation and enhance business performance, so as to help live commerce anchors to achieve better high-quality development. Research design, data, and methodology - This study was conducted by sample survey method on 361 live commercial anchors who have experience in using major online shopping malls for more than one year. Data analysis methods were frequency analysis, confirmatory factor analysis, reliability analysis, correlation analysis, and structural equation model analysis. Result - Hypothesis 1 through Hypothesis 5 were all supported. The results of this study suggest that professionalism and mutual entertainment of live commercial anchors have a significant impact on business performance, survival strategy, resource allocation and environment selection. The resource allocation and environment selection of live commercial anchors play a mediating role in the professionalism and mutual entertainment of live commercial anchors on business performance and survival strategy. Conclusion -The results implied that the professionalism and inter entertainment of live commercial anchors have a positive impact on business performance and survival strategy. In the new situation, live commercial anchors should further improve their professionalism and mutual entertainment, so as to achieve better development.

Analysis of Ultimate Capacity of Plate Anchor on Loading Rate Capacity in Clay (점토 지반에서 인발속도에 따른 판앵커의 극한 인발저항력 분석)

  • Seo, Young-Kyo;Ryu, Dong-Man
    • Journal of Ocean Engineering and Technology
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    • v.27 no.3
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    • pp.15-21
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    • 2013
  • Anchors are primarily designed and constructed to resist outwardly directed loads imposed on the foundation of a structure. These outwardly directed loads are transmitted to the soil at a greater depth by the anchors. Buried anchors have been used for thousands of years to stabilize structures. Various types of earth anchors are now used for the uplift resistance of transmission towers, utility poles, submerged pipelines, and tunnels. Anchors are also used for the tieback resistance of earth-retaining structures, waterfront structures, at bends in pressure pipelines, and when it is necessary to control thermal stress. In this research, we analyzed the uplift behavior of plate anchors in clay using a laboratory experiment to estimate the uplift behavior of plate anchors under various conditions. To achieve the research purpose, the uplift resistance and displacement characteristics of plate anchors caused by the embedment ratio, plate diameter, and loading rate were studied, compared, and analyzed for various cases.

Analysis of Loading Rate Capacity of Plate Anchor in Sand (사질토 지반에 설치된 판앵커의 인발속도에 따른 저항력 분석)

  • Ryu, Dong-Man;Seo, Young-Kyo
    • Journal of Ocean Engineering and Technology
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    • v.26 no.5
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    • pp.31-39
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    • 2012
  • Anchors are primarily designed and constructed to resist outwardly directed loads imposed on the foundation of a structure. These outwardly directed loads are transmitted to the soil at a greater depth by the anchors. Buried anchors have been used for thousands of years to stabilize structures. Nowadays, various types of earth anchors are used for the uplift resistance of transmission towers, utility poles, submerged pipelines, and tunnels. Anchors are also used for the tieback resistance of earth-retaining structures, waterfront structures, at bends in pressure pipelines, and when it is necessary to control thermal stress. In this research we analyzed the uplift behavior of plate anchors in sand using a laboratory experiment to estimate the uplift behavior of plate anchors under various conditions. To achieve the research purpose, the uplift resistance and displacement characteristics of plate anchors caused by the embedment ratio, plate diameter, and loading rate were studied, compared, and analyzed in various cases.

Two Cases of Biodegradable Suture Anchor Displacement Diagnosed with Ultrasonography following Arthroscopic Rotator Cuff Repair

  • Oh, Joo Han;Song, Byung Wook;Rhie, Tae-Yon
    • Clinics in Shoulder and Elbow
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    • v.18 no.4
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    • pp.254-260
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    • 2015
  • With the advancement of shoulder arthroscopy, use of biodegradable suture anchors in the surgical repair of rotator cuff tears has increased. Because of the radiolucency of these anchors, radiography is not appropriate for early detection of anchor failure. Ultrasonography is an advantageous modality in visualizing biodegradable, radiolucent anchors on a real-time basis without risk of radiation exposure. We report on two cases of displacement of a biodegradable suture anchor diagnosed on ultrasonography during the postoperative follow- up, which has not been previously reported. Because this displacement could be missed in the postoperative follow up ultrasonography, we describe the ultrasonographic features of the displaced biodegradable anchors. Surgeons and radiologists should pay special attention to the possibility of displacement of the suture anchor in patients who underwent rotator cuff repairs using suture anchors.

Prediction of Shear Strength for Large Anchors Considering the Prying Effect and Size Effect

  • Kim, Kangsik;Lee, Kwangsoo;An, Gyeonghee
    • International Journal of Concrete Structures and Materials
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    • v.10 no.4
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    • pp.451-460
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    • 2016
  • An anchorage system is necessary in most reinforced concrete structures for connecting attachments. It is very important to predict the strength of the anchor to safely maintain the attachments to the structures. However, according to experimental results, the existing design codes are not appropriate for large anchors because they offer prediction equations only for small size anchors with diameters under 50 mm. In this paper, a new prediction model for breakout shear strength is suggested from experimental results considering the characteristics of large anchors, such as the prying effect and size effect. The proposed equations by regression analysis of the derived model equations based on the prying effect and size effect can reasonably be used to predict the breakout shear strength of not only ordinary small size anchors but also large size anchors.

Fracture Behavior of Cast-in-place Headed Anchors to Concrete (콘크리트 CIP 앵커시스템의 파괴거동에 관한 연구)

  • 박성균;김호섭;윤영수;김상윤
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.491-496
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    • 2000
  • This paper presents the evaluation of behavior and the prediction of tensile capacity of anchors that fail concrete, as the design basis for anchorage. Tests of cast-in-place headed anchors, domestically manufactured and installed in uncracked, unreinforced concrete are performed to investigate the behavior of single anchors and multiple anchors with the consideration of various embedment lengths and edge distances. The failure mode and the load-deformation response of these anchors are discussed and the concrete failure dta are then compared with capacity predictions by the two existing methods : the 45 degree cone method of ACI 349, 318 and the concrete capacity design (CCD) method. Discrepancies between the test results and these two prediction methods, FEM analysis are assessed.

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Cyclic Load Testing of Concrete Expansion Anchors

  • Gary L. Barnes;Lee, Sang-Myung
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05d
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    • pp.404-404
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    • 1996
  • In order to ensure a concrete expansion anchor is suitable for a given application, the load resistance behavior of the anchor must be known. ASTM E488 provides a standard method of testing expansion anchors for static and dynamic loads. Due to the many types of anchors available commercially and the large variability of applications, the ASTM does not delineate all details or requirements necessary to comprehensively determine the dynamic load behavior of concrete expansion anchors. A test program is presented in this paper which was developed and implemented to determine the cyclic load behavior of wedge-type concrete expansion anchors. Test results are also presented along with a discussion of the behavior of anchors, and their suitability for use.

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Kinematic limit analysis of pullout capacity for plate anchors in sandy slopes

  • Yu, S.B.;Merifield, R.S.;Lyamin, A.V.;Fu, X.D.
    • Structural Engineering and Mechanics
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    • v.51 no.4
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    • pp.565-579
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    • 2014
  • The pullout capacity of plate anchors has been studied extensively over the past 40 years. However, very few studies have attempted to calculate the pullout capacity of anchors in sandy slopes. In this paper, three upper bound approaches are used to study the effect of a sloping ground surface and friction angle on pullout capacity and failure of plate anchors. This includes the use of; simple upper bound mechanisms; the block set mechanism approach; and finite element upper bound limit analysis. The aim of this research is to better understand the various failure mechanisms and to develop a simple methodology for estimating the pullout capacity of anchors in sandy slopes.

Uplift response of multi-plate helical anchors in cohesive soil

  • Demir, Ahmet;Ok, Bahadir
    • Geomechanics and Engineering
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    • v.8 no.4
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    • pp.615-630
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    • 2015
  • The use of helical anchors has been extensively beyond their traditional use in the electrical power industry in recent years. They are commonly used in more traditional civil engineering infrastructure applications so that the advantages of rapid installation and immediate loading capability. The majority of the research has been directed toward the tensile uplift behaviour of single anchors (only one plate) by far. However, anchors commonly have more than one plate. Moreover, no thorough numerical and experimental analyses have been performed to determine the ultimate pullout loads of multi-plate anchors. The understanding of behavior of these anchors is unsatisfactory and the existing design methods have shown to be largely inappropriate and inadequate for a framework adopted by engineers. So, a better understanding of helical anchor behavior will lead to increased confidence in design, a wider acceptance as a foundation alternative, and more economic and safer designs. The main aim of this research is to use numerical modeling techniques to better understand multi-plate helical anchor foundation behavior in soft clay soils. Experimental and numerical investigations into the uplift capacity of helical anchor in soft clay have been conducted in this study. A total of 6 laboratory tests were carried out using helical anchor plate with a diameter of 0.05 m. The results of physical and computational studies investigating the uplift response of helical anchors in soft clay show that maximum resistances depend on anchor embedment ratio and anchor spacing ratio S/D. Agreement between uplift capacities from laboratory tests and finite element modelling using PLAXIS is excellent for anchors up to embedment ratios of 6.