• Title/Summary/Keyword: Earth retaining wall

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A Case Study of Evaluating Inertial Effects for Inverted T-shape Retaining Wall via Dynamic Centrifuge Test (동적원심모형실험을 이용한 지진 시 역T형 옹벽의 관성력 영향 분석 사례 연구)

  • Jo, Seong-Bae;Ha, Jeong-Gon;Choo, Yun-Wook;Kim, Dong-Soo
    • Journal of the Korean Geotechnical Society
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    • v.29 no.4
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    • pp.33-44
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    • 2013
  • Mononobe-Okabe (M-O) theory is widely used for evaluating seismic earth pressure of retaining wall. It was originally developed for gravity walls, which have rigid behavior, retaining cohesionless backfill materials. However, it is used for cantilever retaining wall on the various foundation conditions. Considering only inertial force of the soil wedge as a dynamic force in the M-O method, inertial force of the wall does not take into account the effect on the dynamic earth pressure. This paper presents the theoretical background for the calculation of the dynamic earth pressure of retaining wall during earthquakes, and the current research trends are organized. Besides, the discrepancies between real seismic behavior and M-O method for inverted T-shape retaining wall with 5.4m height subjected to earthquake motions were evaluated using dynamic centrifuge test. From previous studies, it was found that application point, distribution of dynamic earth pressure and M-O method are needed to be re-examined. Test results show that real behavior of retaining wall during an earthquake has a different phase between dynamic earth pressure and inertial force of retaining wall. Moreover, when bending moments of retaining wall reach maximum values, the measured earth pressures are lower than static earth pressures and it is considered due to inertial effects of retaining wall.

Earth Pressure Acting on the Cylindrical Retaining Wall of a Shaft in Cohesionless Soils : Study on the Application by Model Test (사질토 지반의 원형수직구에 설치된 흙막이벽에 작용하는 토압 : 적용성 연구)

  • 천병식;신영완;문경선
    • Journal of the Korean Geotechnical Society
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    • v.20 no.4
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    • pp.75-88
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    • 2004
  • It is known that the earth pressure acting on the cylindrical retaining wall in cohesionless soils is small than that acting on the retaining wall in plane strain condition due to three dimensional arching effect. In this study, the earth pressure equation considering the earth pressure decrease by horizontal and vertical arching effects, overburden, wall friction, and failure surface slope is proposed. For the purpose of verifying the applicability of proposed equation, model test is performed with apparatuses that can control wall displacement, wall friction, and wall shape ratio. Influence of each factor on the active earth pressure acting on the cylindrical retaining wall is analyzed according to the model test in constant wall displacement condition. The comparison of calculated results with measured values shows that the proposed equations satisfactorily predict the earth pressure distribution on the cylindrical retaining wall.

Seismic lateral earth pressure analysis of retaining walls

  • Ismeik, Muhannad;Shaqour, Fathi
    • Geomechanics and Engineering
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    • v.8 no.4
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    • pp.523-540
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    • 2015
  • Based on limit equilibrium principles, this study presents a theoretical derivation of a new analytical formulation for estimating magnitude and lateral earth pressure distribution on a retaining wall subjected to seismic loads. The proposed solution accounts for failure wedge inclination, unit weight and friction angle of backfill soil, wall roughness, and horizontal and vertical seismic ground accelerations. The current analysis predicts a nonlinear lateral earth pressure variation along the wall with and without seismic loads. A parametric study is conducted to examine the influence of various parameters on lateral earth pressure distribution. Findings reveal that lateral earth pressure increases with the increase of horizontal ground acceleration while it decreases with the increase of vertical ground acceleration. Compared to classical theory, the position of resultant lateral earth force is located at a higher distance from wall base which in turn has a direct impact on wall stability and economy. A numerical example is presented to illustrate the computations of lateral earth pressure distribution based on the suggested analytical method.

Effects of Relief Shelves on Stability of Retaining Walls

  • Ahn, Taebong
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.9
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    • pp.25-31
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    • 2022
  • Attaching shelf to retaining structure leads to a decrease in the total lateral earth pressure. This decrease enables the retaining structures to become more stable, to have small displacement, and to exhibit lower bending moments, the relief shelves effects are analyzed using FEM in order to understand how they stabilize cantilever wall in this study. Several models are varied by changing location and width of shelves to realize earth pressure and displacements of retaining wall. The displacement is getting smaller because earth pressure acting on shelf increases as shelves locations are lower and width is longer. The ground settlement variation effects caused by relief shelves are studied also. The ground settlement increases abruptly where shelf location is between of 0.5H and 0.625H, and settlement decreases suddenly where shelf width is between b/h=0.375 and b/h=0.500. The shelf significantly reduces earth pressure and movement of the wall. This decrease in the lateral pressure increases the retaining structure stability.

Pseudo-dynamic approach of seismic earth pressure behind cantilever retaining wall with inclined backfill surface

  • Giri, Debabrata
    • Geomechanics and Engineering
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    • v.3 no.4
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    • pp.255-266
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    • 2011
  • Knowledge of seismic earth pressure against rigid retaining wall is very important. Mononobe-Okabe method is commonly used, which considers pseudo-static approach. In this paper, the pseudo-dynamic method is used to compute the distribution of seismic earth pressure on a rigid cantilever retaining wall supporting dry cohesionless backfill. Planar rupture surface is considered in the analysis. Effect of various parameters like wall friction angle, soil friction angle, shear wave velocity, primary wave velocity, horizontal and vertical seismic accelerations on seismic earth pressure have been studied. Results are presented in terms of tabular and graphical non-dimensional form.

Behavior of Reinforced Earth Retaining Wall for Permitting Reinforcement to Subside with Monitoring (현장계측을 통한 보강재 침하형 보강토 옹벽의 거동특성)

  • Chung, Jin-Hyuck;Oh, Jong-Keun;Lee, Song
    • Journal of the Korean Geotechnical Society
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    • v.25 no.2
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    • pp.5-15
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    • 2009
  • The conventional reinforced earth retaining wall has the connector system to fix the reinforcement and block. However, this system defect may cause the crack of block and the rupture of reinforcement due to the stress concentration near the face of reinforced earth retaining wall. Hence, the new connector system which was able to allow the settlement of reinforcement was developed in this study and a test was carried out in the study area which is divided into the conventional reinforced earth retaining wall and reinforced Earth Retaining Wall driving the settlement. As the results of field monitoring in situ, the ratio of tensile force calculated at maximum value on contiguous portion of front block showed that the settlement type decreased the stress concentration near the face of front block greater than the conventional type.

Stability and Earth Pressure Distribution of Excavated Earth Retaining Wall by Centrifugal Model Tests (원심모형실험에 의한 굴착 흙막이벽의 안정 및 토압분포)

  • Kim, Y.C.;Lee, C.K.;Kim, H.J.;Ahn, K.K.;Lee, M.W.;Heo, Y.
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.139-146
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    • 1997
  • In this study, centrifugal model tests were performed to investigate the behavior of excavated earth retaining wall with the depth of excavation and different types of wall(aluminum, steel panel). Jumunjin standard sand was used for foundation soil. The raining method was adopted to form the required relative density of the model ground. The lateral earth pressure measured from tests were compared with estimated active earth pressure by Rankine's theory. The test results have shown that the earth pressure acting on the retaining wall and the rotation displacement of the wall are influenced by the depth of excavation and the type of wall. It was found from the test results that the deformation of the wall increases with the depth of excavation.

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A Study on a Self-supported Earth Retaining Wall with Stabilizing Piles (억지말뚝을 이용한 자립식 흙막이 공법의 개발)

  • Sim, Jae-Uk;Back, Sung-Kwon
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1461-1467
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    • 2005
  • In this study, a new earth retention system has been developed and introduced. This system is a self-supported earth retaining wall without struts. The new earth retention system consists of connected double H-pile and wale. This system provides a larger spacing of support, economical benefit, construction easiness, good performance and safety. This paper explains basic principles and mechanism of self-supported earth retaining wall. In order to investigate applicability and safety of this system, numerical analysis was performed. The finite differential method program, FLAC3D is used. The predicted performances of this system were presented and discussed.

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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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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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