• Title/Summary/Keyword: Earth Retaining

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A Design Method of Earth-Retaining Structure Constructed by a Row of Bored Piles in Cohesive Soils (점성토지반속 주열식 흙막이벽의 설계법)

  • Hong, Won-Pyo;Gwon, U-Yong;Go, Jeong-Sang
    • Geotechnical Engineering
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    • v.5 no.3
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    • pp.29-38
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    • 1989
  • A design method is presented for the earth-retaining structure ccnslructtd by a row of bored Piles, which has such merits as low-vibration and low-noire during construction. And utility of the design method is investigated by performing a design example. First, theoretical rquations to estimate the resisting force of a row of earth-retaining was in cohesive soils are estabilished for grounds above and below bottom of excavation, reprctively. The characteristics of soils and the effect pile's interval can be considered logically in the theoretical equations. Then, the method for stability.analysis is presented for the earth-retaining piles by applying the theoretical equation of resisting forces on a row of piles. Finally, the design of earth-retaining piles is performed within the ranges which can satisfy the stabilities of both piles and soils. On investigation cf the sail-stability, the stability for bottom heave In cohesive soils is also investigated.

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Development of the Analyzing Method for Earth Retaining Cantilever Walls using Stabilizing Piles (억지말뚝을 이용한 자립식 흙막이 공법의 해석기법 개발)

  • Kim, Chang-Young;Im, Jong-Chul;Park, Lee-Keun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.998-1007
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    • 2006
  • In former times, It is obvious that the earth retaining cantilever wall using stabilizing piles is definitely superior to the other methods due to economical efficiency and the efficiency of construction through model tests using a soil tank and practical application(Kim, 2006). However, this method was not proved in theoretical basis from the viewpoint of geotechnical engineering. Accordingly, a variety of model experiments in order to analyze the behavior of the earth retaining cantilever wall and stabilizing piles according to excavation step and earth pressure and stress acting on stabilizing piles according to excavation step were performed. On the basis of analyzing the result of model tests using a soil tank, this study suggests failure mechanism of clods and a method calculating virtual supported point. In addition, this study contributes to developing the analyzing method of retaining piles, stabilizing piles and beams connecting two piles and, this study helps this method to be established as a new design method through analyzing the results of model tests using a soil tank.

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Development of Design Program for Block-type Reinforced Earth Retaining Wall (블록식 보강토 옹벽 설계프로그램 개발)

  • Lee, Chung-Won;Yoo, Ji-Hoon;Min, Yeon-Sik;Chang, Dong-Su;Lim, Hyun-Taek;Moon, Yong-Bae;Kim, Seung-Tai;Kim, Yong-Seong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.56 no.6
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    • pp.75-84
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    • 2014
  • This study aims to develop the program for design of a reinforced earth retaining wall. For this purpose, the external stability such as overturning, sliding and bearing capacity and the internal stability such as pull-out failure and tensile rupture of the reinforced earth retaining wall with the reinforcement spacing and the backfill inclination were examined. In addition, the calculated results from the developed program were verified by comparing with the simulated results based on the three-dimensional finite element analysis. It is expected that this program contributes to effective design of the reinforced earth retaining wall.

Behavior of Reinforced Earth Retaining Wall by Shaking Table Test (진동대 모형실험을 통한 보강토 옹벽의 거동 특성)

  • Yoon, Won-Sub;Yoon, Bu-Yeol
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.6
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    • pp.637-647
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    • 2019
  • In this study, we analyzed seismic behavior of reinforced earth retaining wall through the model test in order to characterize the behavior of reinforced earth retaining wall during earthquake. A scale model test was performed based on similitude ratio in accordance with law of similitude due to time and financial constraints on real scale modeling experiments. Seismic resistance characteristics of each seismic waves were analyzed by assessing the variations measured through excitation of the excited acceleration of 0.05g, 0.1g, 0.15g, and 0.2g. The results of this study, it would be important to obtain reasonable and abundant data on ground properties and seismic design in preparation for earthquakes when assessing the safety of block type reinforced earth retaining wall confined to model experiment. Acquisition of those data and systematic analytical techniques are considered likely to have a significant effect on the decrease of structure damage caused by earthquakes in Korea which has recently witnessed frequent occurrence of earthquakes.

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.

Numerical and experimental study of multi-bench retained excavations

  • Zheng, Gang;Nie, Dongqing;Diao, Yu;Liu, Jie;Cheng, Xuesong
    • Geomechanics and Engineering
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    • v.13 no.5
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    • pp.715-742
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    • 2017
  • Earth berms are often left in place to support retaining walls or piles in order to eliminate horizontal struts in excavations of soft soil areas. However, if the excavation depth is relatively large, an earth berm-supported retaining system may not be applicable and could be replaced by a multi-bench retaining system. However, studies on multi-bench retaining systems are limited. The goal of this investigation is to study the deformation characteristics, internal forces and interaction mechanisms of the retaining structures in a multi-bench retaining system and the failure modes of this retaining system. Therefore, a series of model tests of a two-bench retaining system was designed and conducted, and corresponding finite difference simulations were developed to back-analyze the model tests and for further analysis. The tests and numerical results show that the distance between the two rows of retaining piles (bench width) and their embedded lengths can significantly influence the relative movement between the piles; this relative movement determines the horizontal stress distribution in the soil between the two rows of piles (i.e., the bench zone) and thus determines the bending moments in the retaining piles. As the bench width increases, the deformations and bending moments in the retaining piles decrease, while the excavation stability increases. If the second retaining piles are longer than a certain length, they will experience a larger bending moment than the first retaining piles and become the primary retaining structure. In addition, for varying bench widths, the slip surface formation differs, and the failure modes of two-bench retained excavations can be divided into three types: integrated failure, interactive failure and disconnected failure.

Numerical Analysis on Behavior of Cantilever Retaining Walls (캔틸레버 옹벽의 거동에 대한 수치해석적 연구)

  • Jang, In-Seong;Jeong, Chung-Gi;Kim, Myeong-Mo
    • Geotechnical Engineering
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    • v.12 no.4
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    • pp.75-86
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    • 1996
  • Current methods to estimate the earth pressure for retaining wall analysis are based on Rankine or Coulomb approaches, in which the soil mass behind wall is assumed to reach to failure state with sufficient lateral movements. Some of recent research works carried out by field measurements reveal that the active earth. pressures by Ranking or Coulomb method are underestimated. It means that the lateral movements of wall and soil would not be mobilized enough to reach the failure state. In this study, the finite element method with Drucker -Prager model for soil is employed to investigate the behavior of concrete cantile,tier retaining wall, together with the influence of inclined backfill. The results indicate that the earth pressures on the retaining wall are strongly related to the mobilized lateral movements of wall and soil and that Ranking and Coulomb methods underestimate the resultant earth pressures and the increasing effect on earth pressure by inclined backfill. Based on this study, a simplified method to determine to earth pressures on cantilever retaining wall with horizontal backfill is proposed.

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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.

Model Tests for Measurement of Lateral Earth Pressure on Retaining Wall with the Relieving Platform Using Jumoonjin Sand (주문진 모래를 이용한 선반식 옹벽의 수평토압 측정 모형시험)

  • Moon, In-Jong;Kim, Byoung-Il;Yoo, Wan-Kyu;Park, Yong-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.11
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    • pp.5923-5929
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    • 2013
  • Recently, the retaining wall with the relieving platform has received increasing interests also in Korea in that it can reduce the lateral earth pressure and provide more stability than conventional retaining wall. Previous studies with model tests studies covered only a limited test conditions. In this study, total 15 model tests were performed for various conditions with improved model test apparatus to confirm the effect of decreasing the lateral earth pressure on the retaining wall with the relieving platform. Jumoonjin sand was used for model soil and 2 load cells were used for each 15 layers to measure the lateral earth pressure. Based on the experimental results, the lateral earth pressure of the retaining wall with the relieving platform is less than the that of cantilever wall. The length of the platform and the location of the platform are the key factors influencing the lateral earth pressure.

Study on the Effect of Near Blasting to Earth Retaining Wall by Measuring Underground Vibrations (지중진동 측정을 통한 흙막이 근접발파 영향 연구)

  • Cho, Lae Hun;Jeong, Byung Ho
    • Explosives and Blasting
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    • v.33 no.4
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    • pp.14-24
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    • 2015
  • We conducted test blasting in 3 sites to identify the effect on safety of the earth retaining wall by near blasting vibration. As a test result, we confirm that underground structures(earth anchor et al.) are relatively safer than surface structures as the underground vibration is 10~52% of surface vibration at a same distance. We derived surface and underground vibration prediction equations by regression analysis of measured 3 sites' surface and underground vibration PPV. Also we calculated minimum separation distance by blasting pattern about underground and surface curing concrete. Unless any discontinuity which are unsafe on the earth retaining wall appear, blasting work using under 2.4kg per delay is not meaningful to the earth retaining wall's safety as the result of measuring near blasting vibration, confirming change the earth retaining wall's instrument, and observation of structural deformation.