• Title/Summary/Keyword: Earth Anchor

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Simplified Formulae for Free Earth Supported Anchored Sheet-Pile Wall (앵커식 자유지지 널말뚝벽의 설계용 간편식)

  • Kim, Khi-Woong;Kwon, Min-Seok;Paik, Young-Shik
    • Journal of the Korean GEO-environmental Society
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    • v.3 no.3
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    • pp.37-44
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    • 2002
  • Sheet piles are often used to build continuous walls for the waterfront structures, and also used for some temporary structures, such as the braced cuts. Sheet pile walls may be divided into two basic categories that is cantilever and anchored. Stock(1992) developed an expedient format for determining the depth, maximum bending moment and anchor force of sheet pile wall for cantilever and free earth supported anchored wall. But, that is useful only in case that water table exists above the dredge line. In this study, a simplified formulae was developed for the design of the anchored free earth supported sheet pile wall both in sand and clay by solving the derived equations and regression analysis. It can be used whether the ground water table is above or under the dredge line.

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Analysis of the Earth Resistance for the Tower Footing of T/L (송전선로 철탑기초의 접지저항 해석)

  • Lee, H.G.;Ha, T.H.;Bae, J.H.;Kim, D.K.
    • Proceedings of the KIEE Conference
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    • 2001.11b
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    • pp.344-346
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    • 2001
  • The sharing of common corridors by electric power transmission lines and pipelines is becoming more common place. However, such corridor sharing can result in undesired coupling of electromagnetic energy from the power lines to the near facilities. During a fault on any of the transmission lines, energization of the earth by supporting structures near the fault can result in large voltages appearing locally between the earth and the steel wall of any nearby pipeline. This paper presents the outline of the tower footings for the transmission lines having been used in KEPCO and analyzes the earth resistance for operation method of the tower footing, that is contact presence for the anchor and reinforcing rob of the tower and foundation presence of the underground wiring.

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Stability Evaluation of Earth Retaining Structure using Tower Truss System (새로운 무지보 흙막이 공법의 안정성 평가)

  • Kim, Young-Seok;Kim, Ju-Hyong;Kim, Young-Nam;Kim, Seong-Hwan;Lee, Sung-Reol
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1324-1329
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    • 2009
  • Needs for underground space development and utilization have been increasing in urban area. The conventional strutting method in excavation is effective to restrain the ground movements and displacements of earth structures but inefficient for workers because of small working space. The conventional earth reinforcement methods such as earth-anchor and soil-nailing also have limitation to apply in urban area due to threats to stability of adjacent buildings around excavation boundaries. Recently, many types of earth retaining structures are being developed to overcome disadvantages of conventional excavation methods in urban area. In this study, a series of numerical analyses were performed with MIDAS GTS, geotechnical analysis program and MIDAS Civil, structural analysis design program to evaluate behavior and stability of the new type of non-supporting earth retaining structure, called Temporary Tower System (TTS), consisting of tower truss structures with much economical and spatial advantage.

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Application of Removable Ground Anchor Using Auto back Equipment (Auto back 인장장치를 이용한 제거식 앵커의 적용성)

  • Lee, Song;Lee, Sung-Won;Park, Sang-Kook;Kim, Sa-Dong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.8 no.4
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    • pp.223-230
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    • 2004
  • It is growing the application of the removal ground anchor with tension force for earth retaining constructions in the downtown. Nowadays, we can find the compression dispersion anchor on many site. But, it is occur some probelems in behabior of anchors because of impossible to tense p.c strand uniformly with existing equipment due to different length of p.c strand. So we tried to tense each p.c strand uniformly with auto back equipment in-situ test. This study compared and analyzed apply to elastic theory in-situ test results of an existing equipment with those of auto back equipment. As a result of the test, It has been proved that differences of tension force in the existing equipment increases with increasing the number of p.c strand. This can cause an ultimate failure of the concentrated p.c strand and a shear failure of ground. So it has been proved that auto back equipment is necessary.

An Experimental Study on Connection Strength between Tie-bar and Facing block composing Reinforced Earth (보강토옹벽을 구성하는 타이바와 전면블록의 연결강도에 관한 실험연구)

  • Lee Seung-Hyun;Kim Byoung-Il
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.3
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    • pp.404-408
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    • 2006
  • In this paper, connection strength between facing block and tie-bar was investigated through experimental study with varying in-fill material such as concrete, soil and crushed stone. Also, connection strength between anchor block and tie-bar was investigated with varying in-fill material. According to the experimental results, in case of using in-fill concrete, connection strength between facing block and tie-bar was larger than allowable tension load of tie-bar. Whereas in case of using in-fill soil or crushed stone, connection strength between facing block and tie-bar was less or similiar to allowable tension load of tie-bar. Connection strength between anchor block and tie-bar for which crushed stone was used as in-fill material, was larger than allowable tension load of tie-bar.

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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.

Application by Auto Back Tension System (오토백 인장장치의 적용성)

  • Park, Sang-Kook
    • 기술발표회
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    • s.2006
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    • pp.66-72
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    • 2006
  • The ground anchoring has been utilized over 40 years. It is growing the application of the removal ground anchor with tension force for holding earth retaining constructions in the city. It transmits tension stress of prestressed steel wire through grouting to fixed the ground that is of great advantage adjacent ground stability. Nowadays, we can find the compression dispersion anchor on many site. But, it has some problems in behavior of anchors because of impossible to tense p.c strand uniformly under the existing equipment due to different length of p c strand. Hence, motive of this research was to study the application of the newly developed tension system, that analyze and compare with the current anchoring method build on the data of in-site test and laboratory test. As a result, in case of auto back tension system, it became clear that tension pressure was equally distributed among the steal wires but the existing tension system showed sign of instability by indicating stress deflection of about 30% compare with design load. This can cause an ultimate failure of the concentrated p.c strand and a shear failure of ground.

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Stress Analysis Acting on Electric Pole using Strain Gauge from Full Scale Pull-Out Test (실물인장실험시 변형률계를 이용한 전주에 작용하는 응력분석)

  • Ahn, Tae-Bong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.9
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    • pp.49-55
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    • 2010
  • Many electric poles in the softground have been collapsed due to external load. In this study, 10 types of tests were performed with variation of location, numbers and depths of anchor blocks as well as depth of poles to find stresses acting on concrete electric poles. The stresses of concrete poles are relaxed at 600~700[kg] of tensile load, and stresses are concentrated at top of pole, and spread to lower part of pole. In the concrete pole collapse test, tensile load at failure was approximately 1,400[kg], which is twice of design load. As passive zone in the soil increases, the stresses acting on concrete pole are concentrated at lower part of pole based on moment arm earth pressure distribution.

A Case Study on The Stability and Reinforcement Method at a Rock Slope (암반사면의 안정성검토 및 보강방안에 관한 사례연구)

  • Chun, Byung-Sik;Lee, Seung-Eun;Kong, Jin-Young;Lim, Joo-Heon
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1369-1375
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    • 2006
  • This study analyzes stability and the reason of slope failure about cut slope on stony mountain in Acheondong, Guri and suggests the reasonal reinforce method. Based on the results of the subsurface exploration, laboratory tests, and the numerical analysis of finite element method, the potentials of plane and wedge failure are highly estimated. The safety factor was 1.2 under dry and 1.06 wet condition. The most proper reinforce method to raise the safety factor more than 1.5 was the way to control displacement by using step retaining wall, earth anchor, wire mesh, and rock anchor.

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Estimation of Mobilized Passive Earth Pressure Depending on Wall Movement in Sand (모래지반에서 벽체의 변위에 따른 수동측토압 산정)

  • Kim, Tae-O;Park, Lee-Keun;Kim, Tae-Hyung
    • Journal of the Korean Geotechnical Society
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    • v.36 no.11
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    • pp.51-60
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    • 2020
  • Estimation of passive earth pressure is an important factor in anchor block, temporary retaining wall and support block of raker that resist lateral earth pressure. In practice, due to ease of use, it is common to estimate the earth pressure using the theory of Coulomb and Rankine, which assumes the failure plane as a straight line. However, the passive failure plane generated by friction between the wall surface and the soil forms a complex failure plane: a curve near the wall and a flat plane near the ground surface. In addition, the limit displacement where passive earth pressure is generated is larger compared to where the active earth pressure is generated. Thus, it is essential to calculate the passive earth pressure that occurs at the allowable displacement range in order to apply the passive earth pressure to the design for structural stability reasons. This study analyzed the mobilized passive earth pressured to various displacement ranges within the passive limit displacement range using the semi-empirical method considering the complex failure plane.