• Title/Summary/Keyword: earth pressure

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An Experimental Study on the Characteristics of Earth Pressure to a Debris-fall Prevention Wall (낙석방지벽에 작용하는 토압의 특성에 대한 실험적 연구)

  • Yoon, Nam-Sik;Park, Yong-Won;Park, Myoung-Soo;Choi, Yi-Jin
    • International Journal of Highway Engineering
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    • v.10 no.1
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    • pp.41-48
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    • 2008
  • This paper deals with the characteristics of earth pressure to the debris-fall prevention walls which usually are installed in front of steep slope. Such walls have narrow backfill width where the active soil wedge can not be developed fully. The earth pressure to such walls ue affected by the movement of wall and arching effects due to the friction developing on the surface of adjacent ground slope and wall and therefore cannot be analyzed and calculated reliably. The study is carried out through laboratory model tests using centrifuge test. Test results reveal that the earth pressure to the debris-fall prevention wall depends largely on the inclination angle of the ground slope and the wall movement. The earth pressure reduction due to wall movement was observed at the upper half of wall, while the arching effect was significant at the lower half especially in the case of steep ground slope. It can be said that from the result of this study in the design of a debris-fall prevention wall the earth pressure should be determined considering the inclination of ground slope and the condition of wall movement during and after construction.

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Lateral Earth Pressure against Gravity Walls Backfilled by $C-\phi$ Soil ($C-\phi$ 흙으로 뒤채움한 중력식 옹벽에 작용하는 정적토압)

  • Jeong, Seong-Gyo;Heo, Dae-Yeong;Lee, Man-Ryeol
    • Geotechnical Engineering
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    • v.12 no.4
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    • pp.47-60
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    • 1996
  • Of the classical theories on lateral earth pressure, the Coulomb's and the Rankine's theories, which have been usually used in practice for design of retaining walls, assumed that the lateral earth pressure was a triangular distribution. However, the experimental results obtained by Terzaghi(1934), Tsagreli(1967), Fang & Ishibashi(1986), etc showed that lateral pressure were not triangular distribution. ' In this study, for rigid walls with inclined backfaces and inclined surfaces backfilled by $C-\phi$ soils, an analytical method of earth pressure distribution has been newly suggested by using the concept of the flat arch. The results calculated by the newly suggested equations were compared with ones by the existed theories. And'the influence factors of the earth pressures by the suggested equations were investigated. As a result, the thrusts obtained by this method agree well with those by the existing theories, except the Rankine's solution. It was showed that the height to the centre of pressure(h) depends mainly upon the inclinations of the backface and the backfilled surface, the angle of internal friction, and the adhesion between the wall and the backfilled soil, instead of 0.33H, where H is the wall height.

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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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Earth Pressure on the Cylindrical Wall in Cohesionless Soils (사질토 지반의 원형수직구에 설치된 흙막이벽에 작용하는 토압)

  • 천병식;신영완
    • Journal of the Korean Geotechnical Society
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    • v.19 no.5
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    • pp.175-187
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    • 2003
  • The earth pressure acting on the cylindrical retaining wall in cohesionless soils is different from that on the retaining wall in plane strain condition due to three dimensional arching effect. Accurate estimation of earth pressure is required for the design of vertical cylindrical retaining wall. Failure modes of the ground behind vertical shaft are dependent on ground in-situ stress conditions. Failure modes are actually divided into two modes of cylindrical failure mode and funnel-shaped mode with truncated cone surface. Several researchers have attempted to estimate the earth pressure on cylindrical wall for each failure mode, but they have some limitations. In this paper, several equations for estimating the earth pressure on cylindrical wall in cohesionless soils are investigated and new formulations for two failure modes are suggested. It rationally takes into account the overburden pressure, wall friction, and force equilibriums on sliding surface.

Earth Pressures on Box Culvert Induced by Excavation Geometry (되채움(굴착)의 형상에 따라 매설박스에 유발되는 토압)

  • 정성교;윤치관
    • Geotechnical Engineering
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    • v.12 no.5
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    • pp.27-40
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    • 1996
  • Box culvert has long since been used for various purposes , water and sewerage works, communication and electricity facilities, subway, railway, etc. In urban area, the construetion of box culvert generally consists of excavation-installation of the culvert-backfill. However, the existing design methods for earth pressure on the box culvert do not take into account the excavation(or backfill) geometry. ' A new method considering excavation geometry for earth pressure on box culvert is suggested here. The lateral earth pressures by the newly suggested method agree relatively with results of finite element analyses, but those of existing method are greatly overestimated. The vertical pressure on the top of the box culvert by the new method is similar to those of existing method and finite element analysis. However, the reactional pressure on the bottom of the box culvert depends largely upon the stiffness of the foundation soil. The reactional pressure by the new method agrees well with that of finite element analysis, only when the stiffness is low. From the finite element analysis it is shown that the lateral earth pressure on box culvert depends upon the excavated slope (G) and the net bottom distance (Bc).

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A Discussion on the Improvement of Pseudo-Static Seismic Design Criteria of Retaining Wall in Domestic (국내 옹벽의 유사정적 내진설계기준 개선방향에 대한 고찰)

  • Jo, Seong-Bae;Ha, Jeong Gon;Lee, Jin-Sun;Kim, Dong-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.19 no.2
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    • pp.45-53
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    • 2015
  • This paper reviews the current seismic design code and research for dynamic earth pressure on retaining structures. Domestic design codes do not clearly define the estimation of dynamic earth pressure and give different comments for seismic coefficient, wall inertia and distribution of dynamic earth pressure using Mononobe-Okabe method. AASHTO has been revised reflecting current research and aims for effective seismic design. Various design codes are analyzed to compare their performance and economic efficiency. The results are used to make improvement of current domestic seismic design code. Further, it is concluded that the experimental investigation is also needed to verify and improve domestic seismic code for dynamic earth pressure.

Active Earth Pressure Acting on the Cylindrical Retaining Wall of a Shaft (원형수직구의 흙막이 벽체에 작용하는 주동토압)

  • Chun, Byungsik;Shin, Youngwan
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.4
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    • pp.15-24
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    • 2006
  • It is well known that earth pressure on the cylindrical open caisson and cylindrical retaining wall of a shaft is less than that at-rest and in plane strain condition because of the horizontal and vertical arching effects due to wall displacement and stress relief. In order to examine the earth pressure distribution of a cylindrical wall, model tests were performed in dry sand for the care of constant wall displacement with depth. Model test apparatus which can control wall displacement, wall friction, and wall shape ratio was developed. The effects of various factors that influence earth pressure acting on the cylindrical retaining wall of a shaft were investigated.

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Estimation of 3D active earth pressure under nonlinear strength condition

  • Zhang, D.B.;Jiang, Y.;Yang, X.L.
    • Geomechanics and Engineering
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    • v.17 no.6
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    • pp.515-525
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    • 2019
  • The calculation of active earth pressure behind retaining wall is a typical three-dimensional (3D) problem with spatial effects. With the help of limit analysis, this paper firstly deduces the internal energy dissipation power equations and various external forces power equations of the 3D retaining wall under the nonlinear strength condition, such as to establish the work-energy balance equation. The pseudo-static method is used to consider the effect of earthquake on active earth pressure in horizontal state. The failure mode is a 3D curvilinear cone failure mechanism. For the different width of the retaining wall, the plane strain block is inserted in the symmetric plane. By optimizing all parameters, the maximum value of active earth pressure is calculated. In order to verify the validity of the new expressions obtained by the paper, the solutions are compared with previously published solutions. Agreement shows that the new expressions are effective. The results of different parameters are given in the forms of figures to analysis the influence caused by nonlinear strength parameters.

Pseudo-static solution of active earth pressure against relief shelf retaining wall rotating around heel

  • Yun Que;Jisong Zhang;Chengcheng Long;Fuquan Chen
    • Geomechanics and Engineering
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    • v.39 no.1
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    • pp.87-104
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    • 2024
  • In practical engineering, the design process for most retaining walls necessitates careful consideration of seismic resistance. The prevention of retaining wall overturning is of paramount importance, especially in cases where the foundation's bearing capacity is limited. To research the seismic active earth pressure (ES) of a relieving retaining wall rotating around base (RB), the shear dissipation graphs across various operating conditions are analyzed by using Optum software, and the earth pressure in each region was derived by the inclined strip method combined with the limit equilibrium method. By observing shear dissipation graphs across various operating conditions, the distribution law of each sliding surface is summarized, and three typical failure modes are obtained. The corresponding calculation model was established. Then the resultant force and its action point were obtained. By comparing the theoretical and numerical solutions with the previous studies, the correctness of the derived formula is proved. The variation of earth pressure distribution and resultant force under seismic acceleration are studied. The unloading plate's position, the wall heel's length, and seismic acceleration will weaken the unloading effect. On the contrary, the length of the unloading plate and the friction angle of the filling will strengthen the unloading effect. The derived formula proposed in this study demonstrates a remarkable level of accuracy under both static and seismic loading conditions. Additionally, it serves as a valuable design reference for the prevention of overturning in relieving retaining walls.

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.