• Title/Summary/Keyword: Retaining wall

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Shear Band Formation in Granular Materials with Different Particle Shapes behind a Retaining Wall

  • Zhuang, Li;Kim, Ukgie
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.9
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    • pp.39-47
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    • 2013
  • Local deformations in back filling materials of two sands and one glass bead with different particle shapes behind a rigid retaining wall were studied. Two kinds of boundary conditions were compared: active wall translation and active rotation of the wall about its toe. Effect of the speed of active wall translation was also investigated. The digital image correlation method was used to analyze local deformation developments inside the materials. Test results showed that particle shape and density mainly influence the inclination angle and width of the shear band. The general shear band pattern is strongly dependent on the wall movement mode, while it was little influenced by particle shape. Within a limited range of wall speed in this study, shear band became wider and local deformation became larger with increase of wall speed.

A Relative Study on the Displacement of Earth Retaining Wall by 2 and 3 Dimentional Analysis (2차원 및 3차원 해석에 의한 토류벽의 변위에 관한 비교 연구)

  • Park, Chun-Sik;Park, Hae-Chan;Kim, Jong-Hwan;Park, Young-Jun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.801-810
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    • 2010
  • Until now, design of Earth Retaining is practiced by 2nd dimensional analysis for convenience of analysis and time saving. However, the construction field is 3rd dimension, in this study, practised the 3rd dimensional analysis which can reflect the field condition more exactly the scope of earth retaining wall, and researched about the effective and economical way of design, compared and reviewed with the results, by practising both the 2nd and 3rd dimensional analysis. existing 2nd dimension. the depth of excavation, depth of embedded and soil condition. As result, under the whole conditions, more displacement came to appear to the value as result of 3rd dimensional analysis more than the result of 2nd dimensional analysis. Accordingly, the displacement by the 2nd dimension analysis is underestimated. Moreover, results of 2nd and 3rd dimensional analysis, there is no difference at displacement, when the depth of embedded is 0.5H, 1.0H and 1.5H, but Displacement of 1.5H is smaller than 0.5H, 1.0H. That is, the bigger the depth of embedded becomes, the displacement of Earth Retaining Wall appeared smaller. The displacement of earth retaining wall according to depth of excavation appeared bigger, when the depth of excavation is increased. In the meantime, when the soil condition is different, in the 2nd dimensional analysis, the displacement appeared biggest, in case of the clay layer, but in the 3rd dimensional analysis, in the beginning of excavating, the displacement of earth retaining wall appeared bigger in case of clay layer, but as excavating is in progress, the displacement of both compound soil layer and sand layer appeared big.

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A Relative Study on the Displacement of Earth Retaining Wall by 2 and 3 Dimensional Analysis (2차원 및 3차원 해석에 의한 토류벽의 변위에 관한 비교 연구)

  • Kim, Jong-Hwan;Park, Choon-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09b
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    • pp.181-185
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    • 2010
  • Until now, design of Earth Retaining is practiced by 2 dimensional analysis for convenience of analysis and time saving. However, the construction field is 3 dimension, in this study, practised the 3 dimensional analysis which can reflect the field condition more exactly the scope of earth retaining wall, and researched about the effective and economical way of design, compared and reviewed with the results, by practising both the 2 and 3 dimensional analysis. existing 2 dimension. the depth of excavation, depth of embedded and soil condition. As result, under the whole conditions, more displacement came to appear to the value as result of 3 dimensional analysis more than the result of 2nd dimensional analysis. Accordingly, the displacement by the 2 dimension analysis is underestimated. Moreover, results of 2 and 3 dimensional analysis, there is no difference at displacement, when the depth of embedded is 0.5H and 1.0H, but Displacement of 1.5H is smaller than 0.5H, 1.0H. That is, the bigger the depth of embedded becomes, the displacement of Earth Retaining Wall appeared smaller. The displacement of earth retaining wall according to depth of excavation appeared bigger, when the depth of excavation is increased. In the meantime, when the soil condition is different, in the 2 dimensional analysis, the displacement appeared biggest, in case of the clay layer, but in the 3 dimensional analysis, in the beginning of excavating, the displacement of earth retaining wall appeared bigger in case of clay layer, but as excavating is in progress, the displacement of both compound soil layer and sand layer appeared big.

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Parametric Study on Displacement of Earth Retaining Wall by the Bermed Excavation Using Back Analysis (역해석을 통한 소단굴착에 따른 흙막이 벽체변위의 매개변수 연구)

  • Lee, Myoung-Han;Kim, Tae-Hyung
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.4
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    • pp.23-33
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    • 2015
  • Together with the wall stiffness, a berm has the role of deciding the stability of a temporary retaining wall before structure installation after excavation. Especially in case of loose or soft soil excavated ground, the role of berm is very important. In this study, the measurement data obtained from the temporary retaining wall in the bermed excavation site in urban and numerical analysis are used to investigate the effects of berm's dimension (width and slope), excavation depth and ground property on the maximum horizontal displacement of the temporary retaining wall. The measurement data indicated that the wall displacement varied to the berm's width. That is, as the berm width decreased, the wall displacement increased. As a result of numerical analyses, the maximum wall displacement increased as slope increased and berm width decreased. This means that the berm is effectively restrained to the wall displacement. As excavation depth increased, the effect of berm's slope and width increased. In case of the same berm condition, the wall displacement restrained as ground property increased.

Study on Bending and Shear Strength Setting of Full-scale Model Additional Walls for Additional Wall Test Bed Combined with PHC-W Pile Retaining Wall (PHC-W말뚝 흙막이와 결합된 지하증설벽체 테스트베드 구축을 위한 실대형 지하증설벽체의 휨강도 및 전단강도 설정 연구)

  • Woo, Jong Youl;Yoo, Choong Geon;Kim, Sung Su;Choi, Yongkyu
    • Journal of the Korean Geotechnical Society
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    • v.34 no.12
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    • pp.7-17
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    • 2018
  • Test bed additional wall combined with PHC-W pile retaining wall has been constructed. To determine the dimensions of test bed additional wall, bending and shear tests of full scale core members of additional wall were tested. Basement additional walls utilizing PHC-W pile retaining wall, which were developed by modifying the cross-section of PHC piles, were classified into the composite additional wall and the non-composite additional wall. Their tests were conducted to obtain bending strength and shear strength of basement additional walls ultilizing PHC-W pile retaining wall. Since bending strengths and shear strengths of the composite additional wall and the non-composite additional wall were similar, it could be confirmed that the non-composite additional wall could be applied instead of the composite additional wall. Full-scale model additional wall was 200 mm thick, thus the thickness of additional wall combined with PHC-W pile retaining wall could be reduced by 100~200 mm.

Development of Design Program for Block-type Reinforced Earth Retaining Wall (블록식 보강토 옹벽 설계프로그램 개발)

  • Lee, Chung-Won;Yoo, Ji-Hoon;Min, Yeon-Sik;Chang, Dong-Su;Lim, Hyun-Taek;Moon, Yong-Bae;Kim, Seung-Tai;Kim, Yong-Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.6
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    • pp.75-84
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    • 2014
  • This study aims to develop the program for design of a reinforced earth retaining wall. For this purpose, the external stability such as overturning, sliding and bearing capacity and the internal stability such as pull-out failure and tensile rupture of the reinforced earth retaining wall with the reinforcement spacing and the backfill inclination were examined. In addition, the calculated results from the developed program were verified by comparing with the simulated results based on the three-dimensional finite element analysis. It is expected that this program contributes to effective design of the reinforced earth retaining wall.

Behavior of Full Scaled Geobag Retaining Wall Structure by Field Pilot Test (현장실험을 통한 식생토낭 보강토벽의 거동특성에 관한 연구)

  • Shin, Eun-Chul;Park, Kyung-Won;Shin, Hui-su;Ham, Kyung-Won
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.21-31
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    • 2017
  • Geobag method is an eco-friendly method to minimize the impact on the environment in the construction of retaining wall structure as a kind of geosynthetic reinforced retaining walls. In this study, evaluated behavior of full scaled geobag retaining wall about four different types of geobag retaining walls, that is, non-compacted geobags wall, compacted geobag wall, combination of longitudinal and transversal laied geobags wall, gabion and geobag wall were constructed in the field with instrumentation. Based on the results of field measurement, transversal layered geobag wall for non-compacted case was displaced 30% more than that of mixed gabion wall. Also, the more than 2m geobag walls without reinforcement at the backfill area are turned out to be unstable in terms of wall displacement. On the one hand, the distribution of the earth pressure for all geobag retaining walls sites show within the range of Rankine's and Coulomb's earth pressure after construction. But after intensity rainfall, the transversal laied geobag walls significantly increment of soil pressure. The geobag walls which constructed in the way of mixed wall systems such as gabion and geobag, longitudinal and transversal laied geobags are much stable with comparison of transversal laied geobag wall.

A Study on Cause Analysis and Countermeasures of Chloride Attack of Reinforced Earth Retaining Walls Installed on Bridge Abutment (염해로 인한 교대부 보강토옹벽 손상 원인 분석 연구)

  • Do, Jong-Nam;Kim, Nag-Young;Cho, Nam-Hun;You, Kwang-Ho
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.12
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    • pp.59-64
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    • 2018
  • The damages to the reinforced earth retaining wall are divided into the front wall, foundation, drainage and upper slope. Damage of reinforced earth retaining wall is mainly caused by damage caused by drainage problem in the field. Recently, damage caused by snow removal materials have been occurred. Recently, the amount of snow removal materials used in winter is increasing due to abnormal weather. This chlorides degrades the concrete structure, where the reinforced earth retaining wall was no exception. There has recently been a case in which the front wall of the reinforced earth retaining wall deteriorates due to the chlorides introduced into the back filling portion through the drainage passage. Therefore, in this study, the cause of damages of reinforced earth retaining wall constructed in bridge abutment was analyzed, and an analytical study was conducted on the countermeasure. As a result, it was found that chlorides, which was introduced through the drainage system in the expansion joint of the bridge shift part or the upper structure, is infiltrated into the back part of the reinforced earth retaining wall and damaged. Therefore, it is suggested to improve the drainage system and restored the stiffness of the front wall.

The Comparative Experiment of Geogrid Reinforcement Types with Construction Stage on Segmental Retaining Walls (블록식 보강토 옹벽에서의 시공단계별 보강재 타입에 따른 거동비교)

  • Lee, Sung-Hyouk;Lee, Jin-Wook;Choi, Chan-Yong
    • Journal of the Korean Geosynthetics Society
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    • v.11 no.4
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    • pp.1-8
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    • 2012
  • In this study, the earth pressure, displacement and strain were compared with reinforcement types at segmental retaining wall through full scale model test. The test results found that the measurement of earth pressure and displacement at wall for the fully reinforced retaining wall are different from those for the partly reinforced retaining wall. The analyses of these results would suggest that the used of geoogrid allowed the vertical earth pressure and displacement at wall to be reduced. The horizontal earth pressure in upper and lower part of wall can change with reinforcement type and earth deformation and were larger than the active and the rest pressure. Also, the lateral earth pressure and displacement of wall have a very high a correlation. It was found that the strain contour distribution of reinforcements was occurred a large strain at cental part of wall in segmental retaining wall system.

Investigation of Behaviours of Wall and Adjacent Ground Considering Shape of Geosynthetic Retaining Wall (보강토 옹벽의 형상을 고려한 벽체 및 인접지반 거동 연구)

  • Lee, Jong-Hyun;Oh, Dong-Wook;Kong, Suk-Min;Jung, Hyuk-Sang;Lee, Yong-Joo
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.1
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    • pp.95-109
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    • 2018
  • Recently, GRS (Geosynthetic Retaining Segmental) wall has been widely used as a method to replace concrete retaining wall because of its excellent structural stability and economic efficiency. It has been variously applied for foundation, slope, road as well as retaining wall. The GRS wall system, however, has a weak point that is serious crack of wall due to stress concentration at curved part of it. In this study, therefore, behaviour of GRS wall according to shape of it, shich has convex and concave, are analysed and compared using Finite Element analysis as the fundamental study for design optimization. Results including lateral deflection, settlements of ground surface and wall obtained from 2D FE analysis are compared between straight and curved parts from 3D FE analysis.