• Title/Summary/Keyword: Earth retaining wall

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Experimental study on effect of underground excavation distance on the behavior of retaining wall

  • Lee, Seok-Won
    • Geomechanics and Engineering
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    • v.17 no.5
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    • pp.413-420
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    • 2019
  • The changes in earth pressure and ground settlement due to underground excavation near an existing retaining wall were studied experimentally according to the separation distance between the underground excavation and the retaining wall. In addition, this study attempted to experimentally prove that the arching phenomenon occurred during the construction of the underground space. A model tank having 120 cm in length, 160 cm in height, and 40 cm in width was manufactured to simulate underground excavation through the use of five separated base wall bodies. The variation of earth pressure on the retaining wall was measured according to the underground excavation phase through the use of 10 separated right wall bodies. The results showed that the earth pressure on the retaining wall was changed by the lowering of the first base bottom wall; however, the earth pressure was not changed significantly by the lowering of the third base bottom wall, since the third base wall had sufficient separation distance from the retaining wall. Lowering of the first base wall induced a decrease in the earth pressure in the lower part of the retaining wall; in contrast, lowering of the first base wall induced an increase in the earth pressure in the middle part of the retaining wall, proving the arching effect experimentally. It is necessary to consider the changes in earth pressure on the retaining wall in designing earth retaining structures for sections where the arching effect occurs.

Evaluation of Stability in reinforced Earth Retaining Wall by Vehicle Collision (차량 충돌에 의한 보강토 옹벽의 안정성 평가)

  • Ahn, Kwangkuk;Heo, Yol;Hong, Kinam;Ahn, Minsu
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.6
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    • pp.39-46
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    • 2010
  • The past studies on reinforced earth retaining wall have been mostly focused on the internal and external failure of reinforced earth retaining wall, and the research for external impact was limited on earthquake. However, the potential external impact such as vehicle collision to reinforced earth retaining wall near the road are increasing with development of roads. Therefore, in this study, the reinforced earth retaining wall was modeled by using LS-DYNA, which is a general purpose finite element program recognized for its reliability. The behavior of reinforced earth retaining wall by vehicle speed was analyzed with Ford single unit truck offered by NCAC (National Crash Analysis Center), which is 8 tons weight. In addition, in order to obtain stability of reinforced earth retaining wall for vehicle collision, the gravity retaining wall was applied at the bottom of reinforced earth retaining wall. With varying the height of retaining wall (0.5m, 1.0m, 1.5m), the numerical study was performed to analyze the stability and behavior of reinforced earth retaining wall.

The Evaluation on Behavior of Segmental Grid Retaining Wall by Model Test (압밀주입에 의한 지반개량 특성고찰)

  • Kim, Sang-Su;Bae, Woo-Seok;Lee, Jong-Kyu
    • 기술발표회
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    • s.2006
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    • pp.162-171
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    • 2006
  • Segmental Grid Retaining 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 segmental grid retaining 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 segmental grid retaining wall system differ from that of the concrete retaining wall In this study, the surcharge tests using the scaled model segmental grid retaining 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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Behavior of Reinforced Earth Retaining Wall for Connector System Driving the Settlement of Reinforcement (보강재 침하를 허용하는 연결시스템을 적용한 보강토옹벽의 거동)

  • Jong-Keun Oh;Jeong, Jong-Gi;Lee, Song
    • 기술발표회
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    • s.2006
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    • pp.156-161
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    • 2006
  • Recently, construction of soil-reinforced segmental retaining walls which used geosynthetics are being increased day by day due to its construction efficiency, economic efficiency, and its aesthetic view. The conventional reinforced earth retaining wall has the connector system to fix the reinforcement and block However, this system may cause the crack of block and the rupture of reinforcement due to the stress concentration near the face of reinforced earth retaining wall In this study, the new connector system, which is able to allow the settlement of reinforcement, was applied to analyze the effect of connector system of reinforced earth retaining wall The connection strength tests and centrifugal tests for both the conventional reinforced earth retaining wall and the settlement reinforced earth retaining wall were performed to compare the results

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A case study on the landslide resulted from earth retaining wall failure (옹벽파괴에 의한 사면붕괴 사례연구)

  • Kim, Hyung-Woo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1084-1089
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    • 2009
  • This paper presents the example of landslide triggered by the failure of earth retaining wall. Close examinations such as visual inspections and non-destructive testings revealed that the earth retaining wall does not have enough strength to resist active earth pressure and ground water pressure. This fact is proved to be a direct initiation of landslide. Numerical studies including slope stability analyses and seepage analyses were performed with material properties obtained by geophysical explorations and laboratory tests. The results of numerical studies show that the overturning of the earth retaining wall affects the slope stability, leading to landslide consequently.

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Analysis of Lateral Earth Pressures on Retaining Wall from Traffic Load Distribution (옹벽 상단 교통하중의 분포에 따른 옹벽의 수평 토압 분석)

  • Lee, Kicheol;Kim, Dongwook;Chung, Moon-Kyung
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.4
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    • pp.43-55
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    • 2017
  • The purpose of this study is to investigate the effect of traffic loads on retaining wall stability. There is insufficient research on lateral earth pressure on retaining wall due to traffic load. In addition, limited detailed designs of retaining wall for transportation including number of lanes of road, magnitudes of axle loads, and vehicle formations are available. Because the lateral earth pressure on the retaining wall due to traffic loads is a function of the lateral distance from retaining wall, the wall height, and the locations of lanes, the analysis of lateral load on retaining wall from traffic loads is performed with direct or indirect reflection of these factors. As a result of the analysis, lateral earth loads induced from traffics can be considered negligible if the lateral distance of traffic load from wall exceeds the height of retaining wall. Therefore, it is practically reasonable to consider traffic loads within a lateral distance between wall and traffic load of the height of retaining wall.

Internal Stability of Timber Framed Earth Retaining Wall (목재옹벽의 내적안정 평가에 관한 연구)

  • Lee, Kwang-Wu;Kim, Ju-Hyong;Cho, Sam-Deok
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.2
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    • pp.81-89
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    • 2011
  • This paper introduces a recently developed thinning-out timber framed earth retaining wall system. Timber framed retaining walls are usually designed by using design code of gravity type retaining wall but internal stability of timber framed earth retaining walls is often neglected. In this study, it is recommended to use the design code for segmental retaining walls by National Concrete Masonry Association (NCMA, 1997) to check internal stability of timber framed earth retaining wall. Based on the several shear test results for 3 types of timber frames, a simple design chart including internal stability is suggested.

Model Test Study on the Earth Pressure of the Retaining Wall with the Relieving Platform (선반식 옹벽의 토압에 관한 모형시험 연구)

  • Kim, Byoungil;Yoo, Wankyu;Yang, Mirim;Park, Yongseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1C
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    • pp.27-35
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    • 2012
  • The relieving platform has the advantage of decreasing the total lateral earth pressure on the retaining wall and increasing the overall stability of the structure. Several modeling tests were performed to determine the earth pressure distribution on the retaining wall with a relieving platform and to compare it with that of the cantilever retaining wall. Different types of soil and angle of cutting surface were used to determine the effect of the soil characteristics and the backfill conditions on these earth pressure distributions. From the modeling tests, comparisons between the retaining wall with a relieving platform and the cantilever retaining wall show that the reduction of the lateral earth pressure and deformation of wall was indicated clearly on the retaining wall with a relieving platform. And the overall stability was increased by the relieving platform.

Design Case Study of Permanent Excavation Wall Using Soil Nailing System (쏘일네일링 공법을 적용한 영구 지하굴착 벽체의 설계사례 연구)

  • Park, Si-Sam;Lee, Je-Man;Yoo, Chan-Ho;Kim, Hong-Taek
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.84-91
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    • 2005
  • In case of soil nailing system, there have been many attempts to expand into slope and temporary earth retaining system stabilization method since the first ground excavation earth retaining system construction in 1993. Recently, jointing wall, underground wall of buildings and excavation earth retaining wall, construction were increasingly applied for effective utilization of the limited underground space and land application maximized. However, the application of joining wall into retaining wall or building by temporary soil nailing system and design of permanent wall were performed by using Rankine earth pressure theory without considering the distribution of earth pressure in the soil nailing. In this study was performed to introduce the design case by 'Two-Body Translation mechanism (TBTM)' to be able to consider distribution of earth pressure in the soil nailing when designing the permanent jointing wall using soil nailing system for effective utilization of ground space. Also, this study attempts to evaluate the earth pressure change, decreasing effect of wall displacement and increasing effect of stability when advanced soil nailing system is constructed using $FLAC^{2D}$ ${\nu}er.$ 3.30 program and 'Two-Body Translation mechanism'.

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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.