• Title/Summary/Keyword: anchors

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Pullout Capacity of Ground Anchors in Weathered Soil (풍화토 지반에 설치된 앵커의 인발 특성)

  • 김낙경
    • Journal of the Korean Geotechnical Society
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    • v.17 no.4
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    • pp.231-239
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    • 2001
  • 건설 현장에서 널리 사용되고 있는 그라운드 앵커의 거동 특성을 연구하기 위하여 계측기를 부착한 일곱 개의 그라운드 앵커를 국내에 널리 분포되어 있는 화강 풍화토 지반인 $\bigcirc$$\bigcirc$$\bigcirc$대학교 지반 시험장에 설치하여 인발 시험을 수행하였다. 저압 그라우트 인장형 앵커 3개와 압축형 앵커 4개를 시험하였고, 시험은 AASHTO 규정에 의거한 인발시험, 크리프시험, 장기거동시험을 수행하였다. 시험 결과로부터 화강 풍화토 지반에 설치된 저압그라우트 직선형 앵커의 지반과의 마찰계수, 크리프 변형율, 하중감소 특성을 평가하였다.

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Evaluation of Pullout Capacity of Embedded Suction Anchors in Uniform Clay using Numerical Analysis with ALE(Arbitrary Lagrangian Eulerian) Technique (ALE 기법이 적용된 수치해석을 통한 점토지반에서 석션 매입 앵커의 인발 저항력 평가)

  • Na, SeonHong;Jang, In-Sung;Kwon, OSoon;Lee, Seung-Hyung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2428-2435
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    • 2014
  • Numerical analysis with ALE (Arbitrary Lagrangian Eulerian) Adaptive Meshing technique was performed to evaluate the pullout capacity of the embedded suction anchors (ESA) in uniform clay. The numerical method was verified by the previous study, analytical results based on limit-equilibrium theory and centrifuge tests. The pullout capacity of the ESA under horizontal, vertical, and inclined loading were evaluated, and the effect of initial rotation of the ESA on pullout capacity was also investigated. The analysis results showed that the maximum horizontal capacity was obtained at the mid-point, and the each vertical capacity gave the similar value regardless of the loading points. Furthermore, the inclined capacity was decreased as the load inclination angle increased at the mid-point of the anchor, and almost the same pullout capacity was obtained when the initial rotation angles were below 30 degrees.

Track-Structure Interaction Analysis of Fast Hardening Track on Railway Bridge Considering Effect of Anchor and Friction (앵커와 마찰의 영향을 고려한 교량상 급속경화궤도의 궤도-교량 상호작용해석)

  • Cho, Sang-Hyeon;Lee, Il-Wha;Chung, Won-Seok;Lee, Hee-Young;Lee, Kyoung-Chan
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.31 no.1
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    • pp.53-61
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    • 2018
  • Ballast track requires constant maintenance work due to progress of track irregularity. Fast Hardening Track(FHT) has been developed to reduce the maintenance effort done by injecting fast hardening mortar in aged ballast to convert slab track. For the application of FHT to a railway bridge, post-installed anchors should be placed at center of the track segment to fix it on bridge. This paper presents track-bridge interaction analysis results with FHT considering stiffness and strength of post-installed anchor, age of FHT concrete and friction between FHT and bridge deck surface. Based on the analysis results, this study suggests when is good to install the anchors and allow normal operation of passing train.

Evaluation of Pullout Capacity of Anchors by Bonded Length through Model Test (모형시험을 통한 정착길이별 앵커의 인발저항력 평가)

  • Han, Jae-Myoung;Kim, Gyu-Hyeong;Woo, Jong-Tae;Lee, Kang-Il
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.3
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    • pp.11-19
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    • 2017
  • A series of pullout tests to compression type anchors is conducted. The test is carried out on a couple of steel cables installed in sandy soil with 60% of relative density. The test is performed with 6 different bonded lengths, which are 1, 2, 3, 4, 5, 6 times longer than the initial bonded length (Lc =30 mm). A numerical analysis with the same condition as the test is also performed to compare each other. Finally, those results are compared with theoretical result by Oosterbaan and Gifford (1972). The result shows that the ultimate pullout capacity appears to increase with an increase of bonded length, and that the results of test, numerical analysis and theoretical approach have a good agreement in the ultimate pullout capacity at failure.

Operative Treatment of Medial Epicondylitis: A Comparative Analysis of the Clinical Outcomes between the Suture Anchor Group and the Non-suture Anchor Group

  • Cheon, Sang Jin;Jeon, Woong Ki
    • Clinics in Shoulder and Elbow
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    • v.18 no.4
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    • pp.221-228
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    • 2015
  • Background: The The purpose of this study was to make a comparative analysis of the clinical outcomes after the operative treatment of refractory medial epicondylitis between the suture anchor group and the non-suture anchor group. Methods: We enrolled 20 patients (7 men and 13 women) with recalcitrant medial epicondylitis who were able to receive operative treatment in a minimum of an 18-month follow-up. The mean age was 48.6 years (range, 36-59 years). The patients were allocated into either the suture anchor group (7 patients) or the non-suture anchor group (13 patients). We evaluated clinical outcomes using the visual analog scale (VAS), the pain grading system of Nirschl and Pettrone, and postoperative grip strength. Results: The VAS score decreased from 8.8 to 2.0 for the suture anchor group and from 8.6 to 1.3 for the non-suture anchor group (p=0.16). The postoperative grip strength was 95%, 93% of the non-treated arm in both groups (p=0.32). The postoperative satisfaction level was good in 5 patients and fair in 2 for the suture anchor group and excellent in 5 patients, good, in 4, and fair, in 4 for the non-suture anchor group (p=0.43). The clinical outcomes did not show a statistically significant difference between the two groups. Conclusions: We found that patients with recalcitrant medial epicondylitis were treated reliably with satisfactory clinical outcomes whether or not suture anchors were used. We believe the use of suture anchors when more than 50% of the tendon origin is affected provides an effective and favorable treatment modality.

Development of a Computer Program to Analyze Stability of Slopes Reinforced by the Earth Retention System (활동억지시스템으로 보강된 사면의 안정해석 프로그램 개발)

  • Hong Won-Pyo;Song Young-Suk
    • The Journal of Engineering Geology
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    • v.16 no.1 s.47
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    • pp.45-58
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    • 2006
  • A new computer program SLOPILE(Ver 3.0) is developed to analyze stability of slopes containing an earth retention system composing of piles, nails and anchors. SLOPILE(Ver 3.0) can calculate the slope stability for both planar failure surfaces in infinite slopes and arc failure surfaces. In order to investigate a design adaptability of SLOPILE(Ver 3.0), analysis results of TALREN and SLOPE/W programs are compared with that of SLOPILE(Ver 3.0). SLOPILE(Ver 3.0) can calculate the slopes reinforced by earth retention system such as piles, nails and anchors. But, TALREN and SLOPE/W can not calculate the slope reinforced by piles. As a analysis result of the example case, SLOPILE(Ver 3.0) is accuracy and suitable program for the stability analysis of slopes reinforced by earth retention system. Therefore, SLOPILE(Ver 3.0) is the most suitable program to analyze the slope reinforced by the earth retention system.

Mock-Up Test for Connection of New-Old Concrete of Footing (확대기초의 신구 콘크리트 접합 모형실험)

  • Hwang, Chul-Sung;Yoo, Sung-Won
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.6 no.1
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    • pp.66-71
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    • 2018
  • In general, when an existing pier is enlarged and reinforced using a small diameter pile, bonded anchor with deformed reinforcing bars is used to maintain the integrity of the joint. However, in the case of bonded anchors, the performance depends largely on the type of joint material. Nevertheless, unlike mechanical anchors, there is no standard method for designing appropriate design methods and proper performance evaluation. Therefore, in this study, the performance of the anchoring anchor was evaluated by performing a model experiment using the reinforcing bars and anchor reinforcing bars. Experimental results show that the structural performance of the unbonded specimen is the best, and the failure mode is the punching shear failure. The deflection of the end of the member is smaller than that of the unconnected member, The deflection of the connected member is larger than the deflection of the small connected member. As the load increases, the possibility of slippage of the anchor steel or fold connection rebar is high.

Three-Dimensional Finite Element Analysis of Tieback Walls in Sand

  • Lim, Yu-Jin;Briaud, Jean-Louis
    • Geotechnical Engineering
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    • v.13 no.3
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    • pp.33-52
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    • 1997
  • A three dimensional nonlinear finite element analysis is used to study the influence of various design decisions for tieback walls. The numerical model simulates the soldier piles and the tendon bonded length of the anchors with beam elements, the unbonded tendon with a spring element, the wood lagging with the shell elements, and the soil with solid 3D nonlinear elements. The soil model used is a modified hyperbolic model with unloading hysteresis. The complete sequence of construction is simulated including the excavation, and the placement and stressing of the anchors. The numerical model is calibrated against a full scale instrumented tieback wall at the National Geotechnical Experimentation Site (NGES) on the Riverside Campus of Texas A&M University. Then a parametric study is conducted. The results give information on the influence of the following factors on the wall behavior : location of the first anchor, length of the tendon unbonded zone, magnitude of the anchor forces, embedment of the soldier piles, stiffness of the wood lagging, and of the piles. The implications in design are discussed.

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1 Person Media Based on Person Wide Web for Preventing Privacy Risk (사생활 침해 방지를 위한 Person Wide Web 기반 1인 미디어)

  • Yoon, Jisup;Ma, Jung-Mi;So, Sun-sup;Eun, Seongbae
    • KIPS Transactions on Computer and Communication Systems
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    • v.5 no.10
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    • pp.339-346
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    • 2016
  • 1 person media is becoming the leading trend among several media in the Internet era exploiting the individual desire of showing off. But, the vast accessibility of Internet produces the worry about privacy risk, which concludes in the increasement of closed SNS. In this paper, we propose a system based on PWW (Person Wide Web) where a person is producing a media and share it with other persons. PWW is an information system which consists of a smart-phone, mobile anchors, a standard web document, and his own cloud storage. An information consumer gets the link using his smart-phone from the mobile anchors attached on the objects in the field. The web browser in the smart-phone obtains the web documents designated by the link and presents it. We also explains the 1 person media system based on PWW and presents the example utilized in the field. We compared and analyzed the security factor of the system based on between WWW and PWW, and concluded that PWW is better than WWW in the aspect of security.

An Analysis of the Design of Public Libraries in Culture-led Urban Regeneration (문화적 도시재생을 위한 공공도서관 계획 특성 연구)

  • Moon, Eun-Mi
    • Korean Institute of Interior Design Journal
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    • v.26 no.5
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    • pp.143-151
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    • 2017
  • This study aims to analyze the design of public libraries which act as anchors in culture-led urban regeneration. They have been built as city's symbols as well as catalysts to revitalize city centers and urban spaces since the 1990s. This study finds that the public libraries play roles in the urban development as cultural icons, multi-functional spaces, and public domain. This study examines the five examples of the libraries and finds their important design qualities as follow. First, public libraries are planned to symbolize local culture and history as cultural icons. The shapes of public libraries are expressed with sculptured cultural icons, while their facades are designed to signify cities' identities and images. Second, public libraries in culture-led urban regeneration have multi-functional spaces which provide diverse activities and experiences to visitors. The libraries often have galleries and theaters for cultural life, cafes and shops for daily uses, educational facilities, as well as public services, parking, and transport systems that connect to urban infrastructure. Third, the public libraries become the anchors of surrounding public spaces and cultural buildings. The libraries have the sequences of approach from entry plazas, transitional zones, and entrances to lobbies. Especially the transitional zones between the libraries and the cities that are covered with giant cantilevers expand the libraries' space and establish attractive urban spaces. Forth, the libraries employ nature and cityscapes in their design. The surfaces and openings of the libraries are adjusted to allow many attractive views to visitors. Fifth, the libraries have big lobby spaces which are the centers of the buildings as well as the public domain. The lobby spaces are designed as in-door spaces like out-doors with vertical and horizontal openness that allow the natural flows of light from ceilings, glass walls and vertical voids.