• Title/Summary/Keyword: the reinforced earth wall

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An Experimental Study on Characteristics of Earth Pressure Distribution for Segmental Reinforced Earth Wall (블록형 보강토 옹벽의 토압 특성 연구)

  • 김진만;조삼덕;이정재;백영식
    • Journal of the Korean Geotechnical Society
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    • v.20 no.1
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    • pp.83-90
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    • 2004
  • Retaining walls with reinforced earth have been constructed around the world. The use of reinforced earth is a recent development in the design and construction of earth-retaining structure. It is believed that reinforced retaining wall has some advantages which make construction quite simple basically. It wilt take short construction time relatively, comparing, fur example with reinforced-concrete retaining wall. In addition, low price and easy construction will be good attractive points in practical point of view. In this study, five field-tests monitoring data for lateral pressures on geogrid-reinforced retaining wall have been compiled and evaluated. Based on field-tests it is found that horizontal displacements of the facing was measured to be about 0.19∼0.76% and that the maximum tensile strains of reinforcement was evaluated to be about 0.66∼1.98%. The maximum tensile strains, measured from each site, do not reach 5% of the practical allowable strain of the geogrid. And also it is found that the lateral pressure distributions of reinforced-earth retaining wall are close to a trapezoid shape like a flexible retaining wall system, instead of a theoretical triangular shape.

Field Monitoring of Panel-type Reinforced Earth Walls Using Geosynthetic Strip Reinforcement with Folding Grooves (접힘홈이 형성된 띠형 섬유보강재를 사용한 패널식 보강토옹벽의 현장계측 연구)

  • Lee, Kwang-Wu;Cho, Sam-Deok
    • Journal of the Korean Geosynthetics Society
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    • v.17 no.4
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    • pp.179-188
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    • 2018
  • A new style of panel-type reinforced earth wall is a more integrated structure by connecting the geosynthetic strip reinforcement with a folding groove directly to the front panel through C-shaped insertion hole embedded in the panel. In this study, field measurements were conducted on two reinforced earth walls constructed at different sites to assess the field applicability and structural stability of the new style of panel-type reinforced earth wall. The horizontal displacement of the front panel, tensile deformation of the geosynthetic strip reinforcement, and horizontal earth pressure acting on the panel were measured and analyzed through the field measurements. According to the field measurements, after completion of the reinforced earth wall construction, the maximum horizontal earth pressure applied to the front panel was less than two-thirds of the Rankine earth pressure, and the maximum horizontal displacement of the front panel was less than 0.5% of the wall height, and the maximum tensile strain generated on the reinforcement was less than 1.0%. Therefore, it was found that two reinforced earth walls constructed at different sites remained stable.

Evaluation of Stability for Settlement Free Reinforced Earth Retaining Wall by Centrifuge Model Tests (원심모형실험에 의한 침하자유형 보강토 옹벽의 안정성 평가)

  • Ahn, Kwangkuk;Bae, Wooseok
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.6
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    • pp.23-34
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    • 2006
  • In this study, the centrifugal tests were performed to evaluate the behavior of reinforced retaining wall that allows the settlement of reinforcement strip. To analyze the stability of reinforced retaining wall, which drives the settlement of reinforcement strip, the results were compared with the conventional reinforced retaining wall. In the centrifugal tests, the aluminum plate for the face was used and the aluminum foil was used as a reinforcement. The decomposed granite soil was adopted as a backfill. As a result, the settlement free reinforced retaining wall reached to the failure at 80g-level. In contrast, the conventional reinforced retaining wall was collapsed at 69g-level. It means that the settlement free reinforced retaining wall has the stronger stability than the conventional reinforced retaining wall. Also, vertical earth pressure of the settlement free reinforced retaining wall near the base of wall was higher 16% than that of the conventional reinforced retaining wall.

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Numerical Analysis for Optimum Reinforcement Length Ratio of Reinforced Earth Retaining Wall (보강토옹벽의 최적 보강길이비 산정을 위한 수치해석적 연구)

  • Park, Choonsik;Ahn, Woojong
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.12
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    • pp.5-14
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    • 2018
  • Recently, method of reinforced earth retaining wall have been proposed according to the material of facing, geosynthetic, construction method, and facing slope. However, the regulations such as the design method and detailed review items according to each construction method are not clear, and collapse due to heavy rainfall frequently occurs. In this study, to obtain a more stable technical approach in the design of reinforced earth retaining wall, the combination of the pullout failure of reinforced earth retaining wall and the optimal reinforcement ratio of height using reinforced earth retaining wall using a single strength reinforcement is assumed, optimum design of stiffener, optimal design of superimposed wall and optimum length ratio of reinforcement material of geosynthetics are proposed through safety factor according to reinforcement length ratio (L/H).

CASE STUDY ON SEVERELY-DAMAGED REINFORCED EARTH WALL WITH GEO-TEXTILE IN HYOGO, JAPAN Part II: Numerical simulation into causes and countermeasures

  • Hur, Jin-Suk;Kawajiri, Shunzo;Jung, Min-Su;Shibuya, Satoru
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.11-17
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    • 2010
  • Numerical analysis was carried out in order to simulate the development of the large deformation that took place on the reinforced earth wall, a part of the Tottori expressway planned to pass Hyogo, Japan. Since this reinforced earth wall had experienced unexpected deformation of the wall during construction, the wall was re-constructed twice. However, the wall deformation showed no sign to cease even at the final stage of the construction. Countermeasures to re-stabilize the wall were demanded. In part I of this paper, it was manifested that subsidence of a 3-meter weak soil due to seepage flow was responsible for the large deformation. A part of concrete panel wall was severely damaged due to extremely large pulling force of geotextile induced by the hammock state. As for the countermeasures, "grouting with slag system" was applied to fill voids of the backfill, and also to prevent further development of settlement in the weak soil layer. "Ground anchor" was also considered to achieve the prescribed factor of safety.

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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.

A In-Situ Pullout Experiment of Chain Reinforced Earth Wall (체인 보강토 옹벽의 현장 인발실험)

  • Yu, Chan;Kim, Sang-Su
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.357-360
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    • 2002
  • A in-situ experiment was performed to evaluate the pullout resistance capacity of chains which is used as a reinforcement of reinforced earth wall. It was also considered that chain was combined with a bar or L-type steel angle by the transverse reinforcement member in the experiment. As a result of experiment, it is expected that chain can be safely used as reinforcements of reinforced earth wall, although it is concerned that a theoretical estimation of the pullout resistance capability of chain is too conservative.

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Analysis on Failure Causes and Stability of Reinforced Earth Wall Based on a Field Case (현장사례를 이용한 보강토옹벽의 파괴원인 및 안정성 분석)

  • Hong, Kikwon;Han, Jung-Geun;Lee, Jong-Young;Park, Jai-Seok
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.1
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    • pp.109-114
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    • 2013
  • This paper describes the global stability of the reinforced earth wall, which was collapsed by heavy rainfall. The seepage analysis was conducted to confirm the change effect of groundwater level on slope with reinforced earth wall. The seepage analysis result confirmed that the change of groundwater level is greatly influenced by rainfall. According to the change of groundwater level, the global stability analysis with reinforced earth wall was conducted based on the results of seepage analysis. The safety factor of the slope was 0.476 when the wall is collapsed firstly. The collapse cause analyzed that soil strength was weaken because the ground was saturated by continuous rainfall. Therefore, the global stability, which is considered heavy rainfall, should be conducted at design and construction of reinforced earth 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.