• Title/Summary/Keyword: earth wall

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Effect of Step-Wise Excavation Depth on the Earth Pressure against an Excavation Wall in Rock Mass (암반지층 굴착벽체 발생토압에 대한 단계별 굴착깊이의 영향)

  • Son, Moorak;Adedokun, Solomon
    • Journal of the Korean Geotechnical Society
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    • v.30 no.2
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    • pp.43-52
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    • 2014
  • This paper examined the effect of step-wise excavation depth on the earth pressure against an excavation wall in rock mass. Numerical parametric studies were conducted based on the Discrete Element Method (DEM) to carry out the problems in rock mass. Controlled parameters included step-wise excavation depth, rock types, and joint conditions (joint shear strength and joint inclination angle). The magnitude and distribution characteristics of the induced earth pressure in a jointed rock mass were investigated and compared with Peck's earth pressure for soil ground. The results showed that the earth pressure against an excavation wall in rock mass were highly affected by different rock and joint conditions, and the effect of step-wise excavation depth increased as a rock type is deteriorated more. In addition, it was found that the earth pressure against an excavation wall in rock mass might be considerably different from Peck's empirical earth pressure for soil ground.

Experimental Study on a Gabion Wall Reinforced by a Relatively Short Reinforcement (짧은 보강재가 부착된 가비온 옹벽의 모형실험)

  • Kim, Joon-Seok
    • Journal of the Korean Geosynthetics Society
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    • v.7 no.1
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    • pp.7-11
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    • 2008
  • The Gabion wall have been developed on the basis of experimental works and the method is actively used in the actual site. In this study, a relatively small-scale experiment was carried out to figure out the failure behavior of a Gabion wall reinforced by a relatively short wire net to enlarge the axial tensile resistance which is important factor in the stability. The horizontal and vertical displacement of Gabion wall have been acquired and analyzed. Furthermore the results are compared with the test results for a non-reinforced Gabion wall that is performed at the same condition.

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A Study on the Stability of Cantilever Retaining Wall with a Short Heel (뒷굽이 짧은 캔틸레버 옹벽의 안정성에 관한 연구)

  • Yoo, Kun-Sun
    • Journal of the Korean Geotechnical Society
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    • v.34 no.10
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    • pp.17-28
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    • 2018
  • Important parameters for the stability checks of cantilever wall are the active earth pressure and the weight of soil above the heel of the base slab. If the heel length is so long enough that the shear zone bounded by the failure plane is not obstructed by the stem of the wall, the Rankine active condition is assumed to exist along the vertical plane which is located at the edge of the heel of the base slab. Then the Rankine active earth pressure equations may be theoretically used to calculate the lateral pressure on the vertical plane. However, in case of the cantilever wall with a short heel, the application of Rankine theory is not only theoretically incorrect but also makes the lateral earth pressure larger than the actual pressure and results in uneconomical design. In this study, for the cantilever wall with a short heel the limit analysis method is used to investigate the mechanism of development of the active earth pressure and then the magnitude and location of the resultants of the pressure and the weight of the soil above the heel are determined. The calculated results are compared with the existing methods for the stability check. In case of the cantilever wall with a short heel, the results by the Mohr circle method and Teng's method show max. 3.7% and 32% larger than those of the limit analysis method respectively.

CASE STUDY ON SEVERELY-DAMAGED REINFORCED EARTH WALL WITH GEO-TEXTILE IN HYOGO, JAPAN Part I: Site Investigation into the cause of damage

  • Jung, Min-Su;Kawajiri, Shunzo;Hur, Jin-Suk;Shibuya, Satoru
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.3-10
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    • 2010
  • Case study was carried out on the interpretation of the mechanical behavior of a severely damaged reinforced earth wall comprising geotextile with the concrete panel facing. In this part I, the outline of the damaged reinforced earth wall is in detail described. The background and cause of the damage are discussed based on the results of site investigation. The engineering properties of the fill were examined by performing various in-situ and laboratory tests, including the surface wave survey (SWS), PS-logging, RI-logging, soaking test, the direct shear box (DSB) test, bender element (BE) test, etc. The background as well as the cause for the damage of the wall may be described such that i) a considerable amount of settlement took place over a 3m thick weak soil layer in the lower part of the reinforced earth due to seepage of rainfall water, ii) the weight of the upper fill was partially supported by the geo-textile hooked on the concrete panels (n.b., named conveniently "hammock state" in this paper), and iii) the concrete panels to form the hammock were severely damaged by the unexpectedly large downwards compression force triggered by the tension force of the geotextile. The numerical simulation for the hammock state of the wall, together with counter-measures to re- stabilize the wall is subsequently described in Part II.

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A Study on the Application of Lateral Earth Pressure to Earth Retaining Wall Considering Ground Characteristics in Jeju I - Case of Strut Construction - (제주 지역의 지반 특성을 고려한 흙막이벽의 측방토압 적용에 관한 연구 I -스트럿 공법 시공 사례)

  • Do-Hyeong Kim;Dong-Wook Lee;Hee-Bok Choi;Kwon-Moon Ko
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.2
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    • pp.55-61
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    • 2023
  • This paper describes the comparative results of measured and predicted values for the horizontal displacement of earth retaining wall based on two field cases, In order to examine the application of lateral earth pressure to the earth retaining wall considering the typical ground characteristics (clinker layer) in Jeju. The prediction of the lateral earth pressure causing the horizontal displacement of the retaining wall was performed by elasto-plastic analysis using Rankine earth pressure, Terzaghi & Peck modified lateral earth pressure, and Tschebotarioff lateral earth pressure. As a result, it was confirmed that the maximum horizontal displacement predicted at site A was about 5 times larger than the measured value, and the ground with maximum horizontal displacement occurred by the prediction was found to be the clinker layer. In the case of site B, the predicted value was 4 to 7 times larger than the measured value. In addition, the ground with maximum horizontal displacement and the tendency of horizontal displacement were very different depending on the prediction method. This means that research on lateral earth pressure that can consider regional characteristics needs to be continued, because it is due to the multi-layered ground characteristics of the Jeju area in which bedrock layers and clinker layers are alternately distributed,

A Study on the Indoor Thermal Environment of House Using Earth Brick Wall (황토벽돌벽 주택의 실내온열환경에 관한 연구)

  • 이재윤
    • Journal of the Korean housing association
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    • v.15 no.1
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    • pp.25-32
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    • 2004
  • The purpose of this study is to understand the indoor thermal environment in the earth brick wall building what is called a ecological Architecture. To investigate thermal performances of the earth brick walls, it measured indoor and outdoor air temperature, relative humidity, globe temperature and PMV in reference house. The result of this study were summarized as the followings; 1) When the outdoor average air temperature was $21.8^{\circ}$, livingroom was $24.9^{\circ}$, kitchen was $25.1^{\circ}$ and 2nd floor room was $25.6^{\circ}$ at 150 cm height from the floor. 2) Although the average outdoor relative humidity was 78%, the livingroom was 67.5%. 3) As the air temperature difference between at the top and bottom was $0.6^{\circ}$ in living room, this value was below 1 % of PPD by ASHRAE Handbook. 4) Predicted Mean Vote(PMV) by ISO-7730 was +0.41.

Reliability analysis of a mechanically stabilized earth wall using the surface response methodology optimized by a genetic algorithm

  • Hamrouni, Adam;Dias, Daniel;Sbartai, Badreddine
    • Geomechanics and Engineering
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    • v.15 no.4
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    • pp.937-945
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    • 2018
  • A probabilistic study of a reinforced earth wall in a frictional soil using the surface response methodology (RSM) is presented. A deterministic model based on numerical simulations is used (Abdelouhab et al. 2011, 2012b) and the serviceability limit state (SLS) is considered in the analysis. The model computes the maximum horizontal displacement of the wall. The response surface methodology is utilized for the assessment of the Hasofer-Lind reliability index and is optimized by the use of a genetic algorithm. The soil friction angle and the unit weight are considered as random variables while studying the SLS. The assumption of non-normal distribution for the random variables has an important effect on the reliability index for the practical range of values of the wall horizontal displacement.

The Behavior of Retention Wall By 3-D Finite Element Method (3차원 유한요소해석에 의한 흙막이 벽체의 거동특성)

  • 이진구;장서만;전성곤;이종규
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.347-354
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    • 2001
  • In this study, 3-D FEM analysis are carried out to investigate the effect of the corners and re-entrant corners which can't be analysed by 2-D analysis. The excavation shape is re-entrant type conditions. The wall displacement, earth pressure and effectiveness of the corner struts are investigated in the re-entrant case, The 3D analysis are peformed to evaluate the effect of various factors, such as re-entrant corner size, excavation depth, and presence of struts. The wall displacement and earth pressures are influenced the size of re-entrant corner. Therefore, the effect of re-entrant corner should be considered in the evaluation of the earth pressure and displacement of the corners. Finally, strut-support systems are not effective at the re-entrant corner.

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Active earth pressure behind rigid retaining wall rotating about the top (정점을 중심으로 회전하는 강성옹벽에 작용하는 주동토압)

  • Paik Kyu-Ho;Sagong Myung
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1107-1112
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    • 2004
  • For a rigid retaining wall with rough face, 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.

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Study on Earth Pressure Acting Against Caisson Structure with the Heel (뒷굽이 있는 케이슨 안벽에 작용하는 토압에 대한 연구)

  • Yoo, Kun-Sun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.29 no.2
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    • pp.67-76
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    • 2017
  • In this study, the effect of caisson heel on the active earth pressure is investigated. Using limit analysis method, inclinations of slip surface developed above the heel with different lengths are analyzed. The shorter the heel length, the larger those of inside slip surface, however those of outside slip surface are not changed. According to the relative heel length, relationships of internal friction angle of backfill material - wall friction angle between caisson structure and backfill - friction angle acting on virtual section at the end of heel are presented. Earth pressures acting against caisson structure with relatively short heel are smaller than Rankine earth pressure but always greater than Coulomb earth pressure which does not consider the heel length.