• Title/Summary/Keyword: 모형옹벽

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The Earth Pressure Distribution of Crib Wall (Crib Wall의 토압분포)

  • Oh, Sewook;Kwon, Youngcheul;Bae, Wooseok
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.5
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    • pp.41-48
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    • 2006
  • Crib wall is one of the segmental grid retaining walls using headers and stretchers to establish the framework of the wall. In this method, grids formed by the intersection of headers and stretchers are generally filled with the gravel to maintain the weight of the wall. Therefore, the construction can be carried out with higher speed and much economically when compared with the concrete retaining wall. Furthermore, it has high drain capacity, and environmentally friendly aspects also have been pointed out because the possibility of the planting at the front of the wall. However, in the crib wall method, the relative movement between the individual headers and stretchers was generally recognized, and stress redistribution in the gravel filling was also observed when subjected to the external loading and self-weight of filling. Therefore, it has been thought that the distribution of the earth pressure in the crib wall system differ from that of the concrete retaining wall. In this study, the surcharge tests using the scaled model crib wall was carried out to observe the distribution of the earth pressure in the segmental grid retaining wall. The earth pressure was measured in the six specified height of wall, and the distribution of the pressure was analyzed. Furthermore, the earth pressure by computation or by the test using the concrete retaining wall was also considered to make comparison.

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The Deformation Measurement of Simulated Ground using Movable Orientation Board for Photogrammetry (사진측량용 이동식 표정판을 이용한 모형지반 변형량 측정)

  • Lee, Hyo-Seong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.4
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    • pp.323-331
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    • 2008
  • Digital close-range photogrammetric technique can measure and describe 3D geometric form from 2D image. This technique is a growing applicability in the field of sciences. Nevertheless, civil and mechanical field, which need measurements as precise as possible, use expensive measuring instruments in general. In addition there are occasions for analysis by means of visual method, since appropriate measuring instruments have been not yet available. This study therefore developed digital close-range photogrammetric technique with a movable orientation board to quickly measure deformation before and after destruction from simulated ground model of reinforced-soil wall. Then the results are compared with the measurements obtained using digital theodolite.

Bulging of Reinforced Retaining Walls (보강토옹벽의 배부름에 관한 실험적 연구)

  • Ju, Jae-Woo;Park, Jong-Beom;Na, Hyun-Ho
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.2
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    • pp.45-53
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    • 2011
  • Recently reinforced retaining walls secure their position as a stabilized method of construction replacing concrete retaining walls gradually. However, in the event of using extensible reinforcement, a bulging phenomenon can be happened in the front of reinforced retaining walls. Bulging of reinforced retaining walls means a phenomenon that, in the height of an arbitrary block, the upper part and the lower part of the block don't secure a relative position in design. Therefore, it is judged that it has the necessity to be examined in design since reinforcement needs metamorphosis to some degree to display tensile force. Therefore, the study examined about how extensibility of reinforcement had an effect on movement of reinforced retaining walls through a small-scale model test with aluminum rods. The study used Changhoji(traditional korean paper made from mulberry bark) as inextensible reinforcement and membrane as extensible reinforcement. As the result of the test, rigidity of reinforcement had a lot of effects on displacement of reinforced retaining walls and generally occurrence point of the maximum horizontal displacement had a tendency transferring to the upper part of walls according to rigidity of reinforcement was increased.

Active Earth Pressure behind Rigid Retaining Wall Rotating about the Top (정점을 중심으로 회전하는 강성옹벽에 작용하는 주동토압)

  • 백규호;사공명
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.181-191
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    • 2004
  • For a rigid retaining wall with rough face, the magnitude and distribution of active earth pressure on the wall are affected by the shape of failure surface and arching effect developed in the backfill as well as internal friction angle of the backfill and wall friction angle. Therefore, the practical shape of failure surface and arching effect in the backfill must be considered to acquire accurate magnitude and non-linear distribution of active earth pressure acting on the rigid retaining wall. In this study, a new formulation for calculating the active earth pressure on a rough rigid retaining wall rotating about the top is proposed considering the practical shape of non-linear failure surface and arching effects. Accuracy of the proposed equation is checked through comparisons of calculations from the proposed equations with existing model test results. The comparisons show that the proposed equations produce satisfactory results.

Active Earth Pressure behind Rigid Retaining Wall Rotating about the Base (저점을 중심으로 회전하는 강성옹벽에 작용하는 주동토압)

  • 백규호
    • Journal of the Korean Geotechnical Society
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    • v.20 no.8
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    • pp.193-203
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    • 2004
  • Arching effects in backfill materials generate a nonlinear active earth pressure distribution on a rigid retaining wall with rough face, and arching effects on the shape of the nonlinear earth pressure distribution depends on the mode of wall movement. Therefore, the practical shape of failure surface and arching effect in the backfill changed with the mode of wall movement must be considered to calculate accurate magnitude and distribution of active earth pressure on the rigid wall. In this study, a new formulation for calculating the active earth pressure on a rough rigid retaining wall rotating about the base is proposed by considering the shape of nonlinear failure surface and arching effects in the backfill. In order to avoid mathematical complexities in the calculation of active earth pressure, the imaginary failure surface composed of four linear surfaces is used instead of the nonlinear failure surface as failure surface of backfills. The comparisons between predictions from the proposed equations and existing model test results show that the proposed equations produce satisfactory predictions.

Centrifuge Model Experiments on Behavior of Reinforced Earth Retaining Walls A Study due to Variation of Reinforcements (보강토 옹벽의 거동에 대한 원심모형실험 -보강재 변화에 의한 연구)

  • Heo, Yol;Ahn, Sang-Ro;Lee, Cheo-Keun
    • Geotechnical Engineering
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    • v.9 no.4
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    • pp.45-54
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    • 1993
  • In this paper, the behaviors of reinforced earth retaining walls according to material properties of reinforcement were performed through the centrifuge model tests. Skin element was used flexible aluminum plate in the process of tests. And reinforcements were used with aluminum foil strips and non -woven polyester sheets. As a result of it, model retaining wall utilizing non-woven polyester sheets than aluminum foil strips was supported at high stress level, and maximum horizontal displacement value of skin element was 0.6H height at model walls. In the other hand, coefficient relation diagram for evaluation of horizontal displacement according to skin element location was proposed using test results.

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