• Title/Summary/Keyword: retaining wall method

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Case Study on Application of PHC Pile to Earth Retaining and Retention Wall (옹벽겸용 흙막이벽으로 PHC말뚝의 적용 사례 연구)

  • Han, Jung-Geun;Hong, Ki-Kwon;Eo, Yun-Won;Kim, Sang-Kwi
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.3
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    • pp.37-44
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    • 2006
  • The construction of earth retaining wall and structure which get environmental element have to appling at the same time, then construction period and construction cost increase. These system which is presented to overcomes shortcoming and have function of earth retaining wall and retention wall at the same time. However, because existing method has limit excavation depth, the advanced design pattern more than existing method, rows of pile was applied. The workability and stability of applied design method are evaluated through analyze of construction case. The results confirmed that application design method can solve displacement of pile and limit excavation depth in existing earth retaining wall.

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Characteristics and Applicability of CWS(Continuous Wall System)II Method (CWS(Continuous Wall System)II 공법의 특성 및 적용성)

  • Lim, In-sig;Lee, Jeong-bae;Kim, Jae-dong;Lee, Jai-ho;Woo, Sung-woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.11a
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    • pp.43-47
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    • 2008
  • CWSII method was developed to overcome the problems of frequent occurrence in the application of existing downward construction methods, especially in the case of using slurry wall instead of SCW or CIP as a retaining wall. By the improvements in connecting steel beams with the wall, CWSII method is able to ensure the settlement of a steel beam and the diaphragm effect of a slab while reducing the degree of difficulty and the term of works and the cost of construction. As the desired results, CWS method can be applied as a practical downward construction method regardless of the type of retaining wall. In this paper, besides the concept and features of CWSII method, it can be seen that the method can provide reliable and economical performances by comparing with existing methods.

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A Study on Securing safety through Behavior Analysis of Earth Retaining Wall (흙막이 가시설의 거동 분석을 통한 안정성 확보 방안에 관한 연구)

  • Kim, Kwang-Leyol;Kim, You-Seong;Kim, Seong-Soo
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.4
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    • pp.11-19
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    • 2013
  • Recently despite the development of analysis program and construction technologies, collapse at the many earth retaining wall construction site of the structure due to the economic and human damage has occurred. The results of geothechnical investigation studies field, it was found to differ from the results of the original design. There may be errors parameters calculated from the results of ground investigation in such a case. And it can be estimated that it is irrational to behavior analysis of the earth retaining wall were analyzed by utilizing the parameters. And in this study, parameters that affect the earth retaining wall the correlations were analyzed using elasto-plastic method. Analysis method was changed various parameters (cohesion, subgrade reaction coefficient, load condition) applied to the elasto-plastic method. And due to a change in the behavior of earth retaining wall materials were analyzed. As a result, the cohesion greatly affects the behavior of earth retaining wall materials in various parameters. For this reason, the results of the geothechnical investigation, confirmation of the actual ground is very important in the design of the earth retaining wall. And, calculating accurate and reasonable of the cohesion of the various parameters is very important.

A Study on the Flowable Backfill with Waste Foundry Sand for Retaining Wall (유동특성을 이용한 폐주물사 혼합물의 옹벽뒷채움재 연구)

  • 조재윤;이관호;이인모
    • Journal of the Korean Geotechnical Society
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    • v.16 no.4
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    • pp.17-30
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    • 2000
  • The objective of this study is to evaluate the lateral earth pressure and the stability of small scale retaining wall with waste foundry sand(WFS) mixtures as a controlled low strength materials (CLSM). Three different types of WFS, like Green WFS, Hurane WFS and Coated WFS, were used in this study, and fly ash of Class F type was adopted. To evaluate the lateral earth pressure and the stability of retaining wall, two different samll scale retaining wall tests, which are called an artificially controlled strain method and a natural strain method, were carried out. In case of an artificially controlled strain method, the coefficient of lateral earth pressure, just after backfilling of WF mixtures, was around 0.8 to 1.0, and most of earth pressure was dissipated within 12 hours. In case of a natural strain method, two steps of stage constructions were employed. The mixtures of Hurane WFS and Coated WFS showed fast decrease of earth pressure due to a relatively good drainage. Judging from the sta bility of retaining wall for overturning and sliding, two steps of stage construction for 2 days were enough to finish the backfill of 6-m height of retaining wall. Also, considering the curling effect of WFS mixtures, the stability of retaining wall increased as curling time increased.

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Estimation of Reliability Level and Applicability of LRFD Based on Standard Drawings of Railway Cantilever Retaining Walls (철도 옹벽 표준도의 신뢰도수준 및 LRFD 적용성 평가)

  • Kim, In-Soo;Lim, Heui-Dae;Park, Joon-Mo
    • Journal of the Korean Geotechnical Society
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    • v.31 no.10
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    • pp.61-76
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    • 2015
  • Recently, geotechnical engineering researches have been conducted on the Limit State Design (LSD) for deep and shallow foundations; however, there are very few studies on the retaining wall. As a basic study for the introduction of the LSD of a railway retaining wall, this study evaluates whether the reliability index satisfies the target reliability index for each failure mode in the standard drawing of the retaining wall. It also analyzes the feasibility of the LSD method by using the Load and Resistance Factor Design (LRFD) for the standard drawing of a retaining wall. In a portion of the standard drawing of the railway retaining wall, the reliability indices of the sliding and bearing capacity failure modes did not satisfy the target reliability index, and could not satisfy the limit state by the LRFD. Hence, the standard drawing of the railway retaining wall will need to be revised if the LSD is to be applied.

Shear Band Formation in Granular Materials with Different Particle Shapes behind a Retaining Wall

  • Zhuang, Li;Kim, Ukgie
    • Journal of the Korean GEO-environmental Society
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    • v.14 no.9
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    • pp.39-47
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    • 2013
  • Local deformations in back filling materials of two sands and one glass bead with different particle shapes behind a rigid retaining wall were studied. Two kinds of boundary conditions were compared: active wall translation and active rotation of the wall about its toe. Effect of the speed of active wall translation was also investigated. The digital image correlation method was used to analyze local deformation developments inside the materials. Test results showed that particle shape and density mainly influence the inclination angle and width of the shear band. The general shear band pattern is strongly dependent on the wall movement mode, while it was little influenced by particle shape. Within a limited range of wall speed in this study, shear band became wider and local deformation became larger with increase of wall speed.

Effects of Functional Improvement of Multiaxis Flat Continuous Soil Cement Earth Retaining Wall (다축 평면 연속형 SCW 흙막이 벽체의 개선 효과)

  • Chung, Choong-Sub;Yoo, Chan Ho;Nam, Ho Seong;Choi, In Gyu;Baek, Seung Cheol
    • Journal of the Korean Geotechnical Society
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    • v.39 no.11
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    • pp.7-22
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    • 2023
  • In January 2022, a new legislation was enforced to enhance the safety of underground construction. Consequently, a comprehensive assessment of underground safety is now an integral part of the planning process, including an evaluation of its impact. Ensuring the stability of temporary retaining walls during underground excavation has become paramount, prompting a heightened focus on the assessment of underground safety. This study delves into the analysis of the Multi-axis Flat Continuous Soil Cement Wall retaining wall (MFS) construction method. This method facilitates the expansion of wall thickness in the ground and provides flexibility in selecting and spacing H-piles. Through laboratory model tests, we scrutinized the load-displacement behavior of the wall, varying the H-pile installation intervals using the MFS method. Additionally, a 3-dimensional numerical analysis was conducted to explore the influence of H-pile installation intervals and sizes on the load for different thicknesses of the MFS retaining wall. The displacement analysis yielded the calculation of the height of the arching effect acting on the wall. To further our understanding, a design method was introduced, quantitatively analyzing the results of axial force and shear force acting on the wall. This involved applying the maximum arching height, calculated by the MFS method, to the existing member force review method. The axial force and shear force, contingent on the H-pile installation interval and size applied to the MFS retaining wall, demonstrated a reduction effect ranging from 24.6% to 62.9%.

Correlation between Strut Preloading and Earth Retaining Structures in Deep Excavations (깊은 굴착시 버팀대 선행하중과 흙막이 구조물과의 상호 관계)

  • 양구승;오성남
    • Journal of the Korean Geotechnical Society
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    • v.16 no.2
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    • pp.23-30
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    • 2000
  • The use of strut-preloading method is gradually increasing in braced excavations in Korea. And it is necessary to analyze the effects of strut preloading on the wall deflection, wall bending moment and strut axial force, etc. In this study, by using the analysis method of beams on elasto-plastic foundations, measured data and calculated results of 2 sites are compared and parametric studies of correlation between preloading and earth retaining structures in sandy soils are carried out in strut preloading application. As results, about 50%~75% of design strut load is effective as preloading force in considering the displacement and member forces of earth retaining structures. And the effective stiffiness of strut should be at least 25% of th ideal value in order to restrain the excessive increase of wall deflection and bending moments. As one of some methods to prevent excessive movements in braced excavation, to preload the strut is confirmed as more effective way than to increase the stiffiness of strut in braced wall, if the excessive axial force of strut due to preloading can be avoided.

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Application for Self-Supported Retaining Wall Using Deep Cement Mixing (DCM(심층혼합처리공법)에 의한 자립식 흙막이 적용사례)

  • Jeong, Gyeong-Hwan;Kim, Yong-Wan;Shin, Min-Sik;Han, Kyoung-Tae;Kim, Tae-Hyo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.257-267
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    • 2006
  • The earth retaining wall systems for excavation works in a populated urban area or a poor soil deposit can be limited due to various restriction. Thus there are various methods to be applied for them such as the soldier pile method, the diaphragm wall with counterfort and so on. In this study, the self-supported earth retaining wall using the DCM(Deep Cement Mixing) method, including its merits, demerits and some important characteristics occured in the design and the construction stage, was introduced. It might be reference for the other design and construction procedures using the DCM method.

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Numerical study on the rate-dependent behavior of geogrid reinforced sand retaining walls

  • Li, Fulin;Ma, Tianran;Yang, Yugui
    • Geomechanics and Engineering
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    • v.25 no.3
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    • pp.195-205
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    • 2021
  • Time effect on the deformation and strength characteristics of geogrid reinforced sand retaining wall has become an important issue in geotechnical and transportation engineering. Three physical model tests on geogrid reinforced sand retaining walls performed under various loading conditions were simulated to study their rate-dependent behaviors, using the presented nonlinear finite element method (FEM) analysis procedure. This FEM was based on the dynamic relaxation method and return mapping scheme, in which the combined effects of the rate-dependent behaviors of both the backfill soil and the geosynthetic reinforcement have been included. The rate-dependent behaviors of sands and geogrids should be attributed to the viscous property of materials, which can be described by the unified three-component elasto-viscoplastic constitutive model. By comparing the FEM simulations and the test results, it can be found that the present FEM was able to be successfully extended to the boundary value problems of geosynthetic reinforced soil retaining walls. The deformation and strength characteristics of the geogrid reinforced sand retaining walls can be well reproduced. Loading rate effect, the trends of jump in footing pressure upon the step-changes in the loading rate, occurred not only on sands and geogrids but also on geogrid reinforced sands retaining walls. The lateral earth pressure distributions against the back of retaining wall, the local tensile force in the geogrid arranged in the retaining wall and the local stresses beneath the footing under various loading conditions can also be predicted well in the FEM simulations.