• Title/Summary/Keyword: Anchor load

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TWO-DIMENSIONAL PHOTOELASTIC ANALYSIS ON VARIOUS TYPES OF COPING DESIGNS UNDER OVERDENTURE (Overdenture의 지대치 Coping형태에 따른 광탄성 응력 분석)

  • Yang, Hye-Ryung;Vang, Mong-Sook
    • The Journal of Korean Academy of Prosthodontics
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    • v.29 no.2
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    • pp.103-115
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    • 1991
  • This study was executed to analyze the stress distribution of tooth, supporting structure and overdenture by two-dimensional photoelastics when 6 types of coping were inserted. Types of coping were designed to be inclined plane, short dome, medium dome, shore square, medium square and o-p anchor attachment. Fortes were applied respectively as follows: 1) Vertical load of 10 kg on the incisal edge 2) $30^{\circ}$ diagonal load of 8 kg on the labial surface. The results were as follows: 1. In case of short dome and o-p anchor attachment, the stress is evenly distributed on teeth, supporting tissue structure under vertical and $30^{\circ}$ diagonal load, then short dome and o-p anchor attachment show better stress distribution and stabilization of overdenture than any other coping under labial diagonal load. 2. Inclined plane revealed greater tendency of displacement of overdenture than any other coping under labial diagonal load. 3. Long height of copings had greater concentration of stress than short height of copings. 4. In case of medium dome under labial diagonal load, there were high level of stress concentration on denture base contacted labioincisal angle of coping.

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Pullout resistance of concrete anchor block embedded in cohesionless soil

  • Khan, Abdul J.;Mostofa, Golam;Jadid, Rowshon
    • Geomechanics and Engineering
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    • v.12 no.4
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    • pp.675-688
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    • 2017
  • The anchor block is a specially designed concrete member intended to withstand pullout or thrust forces from backfill material of an internally stabilized anchored earth retaining wall by passive resistance of soil in front of the block. This study presents small-scale laboratory experimental works to investigate the pullout capacity of a concrete anchor block embedded in air dry sand and located at different distances from yielding boundary wall. The experimental setup consists of a large tank made of fiberglass sheets and steel framing system. A series of tests was carried out in the tank to investigate the load-displacement behavior of anchor block. Experimental results are then compared with the theoretical approaches suggested by different researchers and codes. The appropriate placement of an anchor block and the passive resistance coefficient, which is multiplied by the passive resistance in front of the anchor block to obtain the pullout capacity of the anchor, were also studied.

A Comparative Analysis of Displacement Measurement of the Earth Surface by Load for Root Anchor Block and Rectangle Anchor Block (기초근가와 기존근가의 하중에 따른 변위 비교분석)

  • Mun, Sung-Won;Kim, Jeom-Sik;Kim, Do-Young;Park, Yong-Beom
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.6
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    • pp.863-869
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    • 2013
  • In this paper, we compared and analyzed for safety 1.2m rectangular anchor block and arch-type root anchor block. First, numerical analysis was performed three-dimensional nonlinear method by numerical model test using finite element analysis program "Visual FEA". Then, measure displacement of the surface of the earth after construct each anchor block at 14M electric pole and increase loads through field verification tests for safety evaluation.

Performance test of Chemical Anchor Bolts for Concrete Repair (콘크리트보수용 접착제를 이용한 Anchor Bolt의 인발지지력 산정에 관한 실험적 연구)

  • Kim, Yon-Gon
    • Journal of the Korean Society of Safety
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    • v.17 no.2
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    • pp.85-91
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    • 2002
  • A research on the performance of retrofit anchors was conducted using adhesives for rehabilitation. From the pull-out tests of the chemical anchors, the effect of the hole diameter, spacer, temperature, moisture, embedment depth, and aging time were investigated. The spacer did not directly increased the pull-out load hilt increased post-yielding resistance therefore the ductility of the retrofit anchors. When the hole was cleaned and dried after the immersion, the pull-out load was greatly increased compared to the wet hole. A design equation was unposed depending on the embedment depth of the anchor bolt.

Shear Strength of Anchors under Load Applied Angle and a Group Anchors at an Edge (앵커간격 및 하중방향에 따른 앵커의 전단내력)

  • Kim, Sung-Yong
    • Journal of the Korean Society of Hazard Mitigation
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    • v.3 no.3 s.10
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    • pp.133-141
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    • 2003
  • This study concerns the prediction of shear capacity, as governed by concrete breakout failure of the anchors under load applied angle and an group anchors at an edge and installed in uncracked, unreinforced concrete. For this purpose, the methods to evaluate the shear capacity of the anchors in concrete are summarized and the experimental data are compared with capacities by the two present methods: the method of ACI 349-90 and concrete capacity design (CCD) method.

Characteristics of Behavior of Pressurized light-weight steel Anchor according to undrained shear strength (비배수 전단강도에 따른 압입식 경량강재앵커블록의 거동 특성)

  • Heo, Yol;Ahn, Kwang-Kuk;Park, Kyoung-Soo;Lee, Yong-Jun;Kang, Hong-Sig
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.219-224
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    • 2009
  • In this study, the characteristics of pullout behavior of Pressurized light-weight steel Anchor was investigated through centrifuge model tests considering pull-out angle $0^{\circ}$ with changing undrained shearstrength(0~1, 2~4, 5~7kPa) of clay. According to the results of tests, the yield pullout load of clay ground was gradually increased up to 30% as undrained shear strength was increased. Therefore, it was known that the yield pullout load was affected by increasing the undrained shear strength, in addition, the pattern of behavior was not changed.

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A review on uplift response of symmetrical anchor plates embedded in reinforced sand

  • Niroumand, Hamed;Kassim, Khairul Anuar
    • Geomechanics and Engineering
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    • v.5 no.3
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    • pp.187-194
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    • 2013
  • The most soil anchor works have been concerned with the uplift problem on embedded in non-reinforced soils under pullout test. Symmetrical anchor plates are a foundation system that can be resisting tensile load with the support of around soil in which symmetrical anchor plate is embedded. Engineers and authors proved that the uplift response can be improved by grouping the symmetrical anchor plates, increasing the unit weight, embedment ratio and the size of symmetrical anchor plates. Innovation of geosynthetics in the field of geotechnical engineering as reinforcement materials found to be possible solution in symmetrical anchor plate responses. Unfortunately the importance of reinforcement in submergence has received very little attention by researchers. In this paper, provision of tensile reinforcement under embedded conditions has been studied through uplift experiments on symmetrical anchor plates by few researchers. From the test results it has been showed that the provision of geogrid reinforcement system enhances the uplift response substantially under uplift test although other results are such as increase the ultimate uplift response of symmetrical anchor plate embedded using geosynthetic and Grid Fixed Reinforced (GFR) and symmetrical anchor plate improvement is very dependent on geosynthetic layer length and increases significantly until the amount of beyond that further increase in the layer length does not show a significant contribution in the anchor response.

Experimental and numerical investigation of uplift behavior of umbrella-shaped ground anchor

  • Zhu, Hong-Hu;Mei, Guo-Xiong;Xu, Min;Liu, Yi;Yin, Jian-Hua
    • Geomechanics and Engineering
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    • v.7 no.2
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    • pp.165-181
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    • 2014
  • In the past decade, different types of underreamed ground anchors have been developed for substructures requiring uplift resistance. This article introduces a new type of umbrella-shaped anchor. The uplift behavior of this ground anchor in clay is studied through a series of laboratory and field uplift tests. The test results show that the umbrella-shaped anchor has higher uplift capacity than conventional anchors. The failure mode of the umbrella-shaped anchor in a large embedment depth can be characterized by an arc failure surface and the dimension of the plastic zone depends on the anchor diameter. The anchor diameter and embedment depth have significant influence on the uplift behavior. A finite element model is established to simulate the pullout of the ground anchor. A parametric study using this model is conducted to study the effects of the elastic modulus, cohesion, and friction angle of soils on the load-displacement relationship of the ground anchor. It is found that the larger the elastic modulus and the shear strength parameters, the higher the uplift capacity of the ground anchor. It is suggested that in engineering design, the soil with stiffer modulus and higher shear strength should be selected as the bearing stratum of this type of anchor.

Horizontal Displacement Analysis of Electric Pole from Full Scale Pull-Out Test in Softground (연약지반에 시공된 전주의 실물인장실험을 통한 수평변위분석)

  • Ahn, Tae-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.12
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    • pp.115-126
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    • 2009
  • Many electric poles in the softground have been collapsed due to external load such as typhoon wind load. In this study, the location, numbers and depths of acnchor blocks as well as depth of poles were varied to find horizontal displacement of poles through pull-out tests. The 10 types of tests were performed, and lateral displacements showed differences depending on location, numbers and depth of poles. The bending is generated in the upper part at the initial load, but it moved to central part as load increased. The maximum horizontal displacement decreased to 1/1.6 at -0.5[m] depth of anchor block and 1.3[m] additional laying depth of poles into ground. Two anchor blocks of poles are better than one acnchor block system, but one anchor block system is recommended because difference of displacement is not too large, and constructibilty is bad due to increase of excavation for anchor blocks.

Study on large tonnage pile foundation load test system and field test of long rock-socketed pile

  • Zhang, Xue-feng;Ni, Ying-sheng;Song, Chun-xia;Xu, Dong
    • Geomechanics and Engineering
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    • v.21 no.6
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    • pp.565-570
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    • 2020
  • Large tonnage pile foundation load test system is designed in this paper by using pre-stressed technique to optimize the design of anchor pile reaction beam system, in which project pile can be successfully taken as anchor pile. The test results show that the cracks and excessive deformations of the prestressed anti-force device designed in this study have not occurred, and the prestressed tendons of the anchor pile ensure that the anchor pile will not be pulled and fractured, and the prestressed tendons can be reused, thus ensuring the safety and reliability of the test. This test method can directly test bearing capacity of long rock-socketed piles, and analysis bearing behaviors from test results of sensors which embedded in the pile. Through test studied, authors summarized the vertical bearing characteristics of long rock-socketed piles and the main problems that should be paid attention to during design and construction, and provided reliable solutions.