• Title/Summary/Keyword: Rankine's earth pressure

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Earth Pressure Distribution with Rigid Retaining Wall Movements (강성토유벽의 움직임에 따른 토압분포)

  • 강병희;채승호
    • Geotechnical Engineering
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    • v.5 no.1
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    • pp.47-60
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    • 1989
  • Lateral earth Pressure distributions due to the ,randy soil backfill behind the rigid vertical walls for three different wall movement modes are obtained by the elasto-plastic finite element analys of soil deformation, and these earth pressures are compared with both Rankine's and Dubrova's active earth pressures. Thereby, the effects of the magnitude and the mode of wall displacement on the earth pressure distribution are investigated. Three different modes of wall movement considered in this study are the rotation about bottom, the rotation about top and the translation. For the case of the wall rotation about top, the earth pressure distribution is shown as a reverse S-curve-shaped distribution due to the arching effect. Consequently, the point of application of the lateral thrust is much higher than one-third of the wall height from the base. And, comparing the other modes of wall movement, the magnitude and the point of appliestion of the lateral thrust for the wall rotation about top are larger and higher, respectively. The wedge-shaped plastic zone in the backfill at active failure is developed only for the mode of wall rotation about bottom. The lateral earth pressure distributions on the walls with inclined backfill of several different slopes are shown for the mode of wall rotation about bottom.

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A Study on the Application of Soil-Reinforced Retaining Wall for Excavation Slope (절토사면에서 보강토 옹벽의 적용성 연구)

  • Byun, Yoseph;Wrryu, Woongryeal;Lee, Dongho;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.2
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    • pp.53-60
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    • 2010
  • Considering environmental issues and lack of space, it is a necessity to minimize the amount of excavation. Various types of excavation methods are being used in practice. This study proposes a reasonable method for estimating the earth pressure acting on a reinforced wall in front of a excavated slope. The measured data in the field and numerical analyses were used. Results of the study shows that the earth pressure acting on the excavated wall is less than that estimated by Rankine's equations. It was shown that when the excavated slope is used with the reinforced wall, the pressures acting on the reinforced wall can be greatly reduced.

The Behavior of Earth Retaining Walls Applied to Top-Down Construction Method Using Back Analysis (Top-Down 공법이 적용된 흙막이벽의 역해석을 이용한 거동분석)

  • Hong, Won-Pyo;Kang, Chul-Joong;Yun, Jung-Mann
    • The Journal of Engineering Geology
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    • v.22 no.1
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    • pp.39-48
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    • 2012
  • The behaviors of a diaphragm wall and a contiguous pile wall such as CIP(Case-in-place pile) and SCW(Soil-cement wall), applied to the top-down construction method, were analyzed using the SUNEX program, which is widely used to design earth retaining walls. Four types of earth pressures, as described by Rankine (1857), Terzaghi and Peck (1967), Tchbotarioff (1973), and Hong and Yun (1995a), were applied to the analysis program to predict the lateral displacement of walls. The results show that the displacements of an earth retaining walls vary with the applied earth pressure. The predicted lateral displacement based on Hong & Yun's (1995a) earth pressure is similar to the measured displacement. Therefore, the actual lateral displacement of an earth retaining wall, as applied to top-down construction method, can be accurately predicted by using an analysis program considering Hong and Yun's (1995a) earth pressure.

Proposal of Mobilized Passive Earth Pressure to Allowable Wall Displacement and Movement Types in Sandy Soil (벽체 허용변위와 양상을 고려한 사질토지반에서 수동측토압 제안)

  • Yoon, Young-Ho;Kim, Tae-Hyung;Kim, Tae-O;Woo, Min-seok
    • Journal of the Korean Geotechnical Society
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    • v.39 no.7
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    • pp.5-15
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    • 2023
  • The evaluation of passive earth pressure plays a crucial role in the design of earth-retaining structures such as retaining walls and temporary earth-retaining walls to withstand horizontal earth pressure. In the earth pressure theory, active and passive earth pressures represent the earth pressures at the limit state, where the wall displacement reaches the maximum allowed displacement. In the design of earth-retaining structures, the passive earth pressure is considered as the resisting force. In this context, the limit displacement at which passive earth pressure occurs is significantly greater than that associated with the active earth pressure. Therefore, it is irrational to apply this displacement directly to the calculation of passive earth pressure. Instead, it is necessary to consider the mobilized passive earth pressure exerted at the allowable horizontal displacement to evaluate the structural stability. This study proposes an allowable wall displacement, denoted as 0.002 H (where H represents the excavation depth), based on a literature review that focuses on sandy soils. To calculate the mobilized passive earth pressure from the wall displacement, a semi-empirical equation is proposed. By analyzing the obtained data on mobilized passive earth pressure, a reduction factor applicable to Rankine's passive earth pressure is proposed for practical application in sandy soils under different wall movement types.

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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Active Eanh Pressure Against Caisson Backfilled with Crushed Rock and Sand (II) : Verification and Application (사석과 모래로 뒷채움된 케이슨에 작용하는 주동토압 (II) : 검증과 적용)

  • Paik Kyu-Ho
    • Journal of the Korean Geotechnical Society
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    • v.22 no.2
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    • pp.29-39
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    • 2006
  • In the companion paper (Paik 2006), a new formulation for calculating the nonlinearly distributed active earth pressure acting on a caisson backfilled with crushed rock and sand is proposed, and it takes into account arching effects as well as difference in internal friction angles and unit weights between sand and crushed rock. In this study, in order to partially check the accuracy of the proposed equation, the results of the proposed equation are compared with the equation proposed by Paik (2003a) for caissons with rough surface and homogeneous backfill, and are compared with results of Rankine's theory for caissons with smooth surface and homogeneous backfill. In addition, a parametric study is performed to investigate the effect of $phi_{r}$, $phi_{s}$, $\delta_{r}$, $\gamma_{r}$, $\gamma_{s}$ and $\beta$ on the magnitude of active earth pressure acting on the caisson, and construction methods for minimizing active earth pressure on the caisson are also provided based on the results of a parametric study.

Effect of Groundwater Flow on the Behavior of Circular Vertical Shaft (지하수 유동을 고려한 원형수직구 거동분석)

  • Park, Heejin;Park, Jongjeon;Jeong, Sang-Seom
    • Journal of the Korean Geotechnical Society
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    • v.38 no.6
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    • pp.29-39
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    • 2022
  • This study investigates the behavior of a circular vertical shaft wall in the absence and presence of a groundwater table. The effects of wall deflection, backfill settlement, and earth pressure distribution around the circular vertical shaft caused by sequential excavations were quantified. The vertical shaft was numerically simulated for different excavation depths of the bearing layer (weathered soil, weathered rock, soft rock) and transient and steady-state flows in the absence of a groundwater table. The backfill settlements and influential area were much larger under transient flow conditions than in steady-state flow. On the contrary, the horizontal wall deflection was much larger in steady state than in the transient state. Moreover, less settlement was induced as the excavation depth increased from weathered soil to weathered rock to the soft rock layer. Finally, the horizontal stresses under steady- and transient-state flow conditions were found to exceed Rankine's earth pressure. This effect was stronger in the deeper rock layers than in the shallow soil layers.

Stress Release Zone Around Sub-structure Constructed by Non-open Cut Methods (비개착공법으로 건설된 지하구조물 주변 지반 응력이완영역 규명)

  • Seo, Ho-Sung;Cho, Kook-Hwan
    • Journal of the Korean Society for Railway
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    • v.19 no.4
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    • pp.480-488
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    • 2016
  • For the development of areas around railway lines, subsurface construction using the non-open cut method under the railway has recently been increased. However, when a structure under a railway is constructed, the stress release of the ground is not considered an important factor in the design. In this study, laboratory tests were conducted to determine a zone of stress relaxation. Field tests using an inclinometer were performed to measure the horizontal displacement of the ground during non-open cut construction. The stress release zone and the subgrade stiffness were investigated by numerical analysis. The results of the laboratory tests indicated that the failure zone in the ground was similar to a Rankine's active earth pressure zone. The measured data from the inclinometer in the field tests showed that displacements started when a steel pipe was pushed into the ground. The results of numerical analysis show that lateral earth pressure was also close to Rankine's active earth pressure. The roadbed support stiffness of the soil around the structure decreased to 40% of the original value. The ground around the subsurface structure constructed using nonopen cut methods should be reinforced to maintain the running stability of train.

Behavior of Dry-stone Segmental Retaining Wall Using Physical Modeling and Numerical Simulation (모형시험과 수치해석을 이용한 조적식 석축옹벽의 거동 특성)

  • Kim, Seong-Su;Mok, Young-Jin;Jung, Young-Hoon
    • Journal of the Korean Geotechnical Society
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    • v.27 no.9
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    • pp.25-36
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    • 2011
  • The behavior of the dry-stone masonry retaining structure has been investigated via physical model test and numerical simulation. In the model test, the digital image analysis using PIV technique was employed to measure horizontal displacements in the backfill soils and retaining blocks. For finite element numerical analyses, the commercial code, ABAQUS, was used. The horizontal displacements observed in the model test showed that the development of the failure surface is progressive. Numerical results showed that in most cases horizontal earth pressure is distributed similarly to a conventional Rankine’s distribution. However, lower values of the internal friction angle of the backfill soils and interface friction angle in the front blocks produce irregularly nonlinear distribution of the horizontal earth pressure.

Tension Crack and Lateral Pressure on Gravity Wall Backfilled by Cohesive Soil : Undrained Analysis (점성토로 뒤채움된 중력식옹벽에서의 인장균열 및 수평토압 : 비배수 해석)

  • 정성교;김형수
    • Geotechnical Engineering
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    • v.13 no.4
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    • pp.135-148
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    • 1997
  • Coulomb's theory has been usually used in practice to obtain lateral earth pressure against retaining wall. Such theory is based in the assumption that the lateral pressure is a tai angular distribution, since the point of applying the lateral thrust cannot be obtained by using it. However, the results of laboratory and field tests showed that the lateral pressure was not a triangular but a nonlinear distribution. To overcome the drawback of the Coulomb's theory, the different theoretical approaches(Handy, 1985. Kingsley, 1989 : Kellogg, 1993, Chung et at,1993, 1996a) were performed for gravity wall backfilled by cohesionless soil. On the other hand, for retaining wall backfilled by ,cohesive soil, theoretical analyses were carried out only on the basis of the Rankine's or Coulomb's concepts, but the equations showed different results. Here was newly derived the equations of lateral pressures under undrained condition against gravity wall backfilled by cohesive soil. They were based on the Coulomb's wedge, adopted the arching concept. Some of the equations were derived by neglecting tension crack, while the others by considering it. Comparative results for applying different examples showed that the equation considering tension crack might be reasonable.

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