• Title/Summary/Keyword: Retaining Structure

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Parametric Study on Displacement of Earth Retaining Wall by the Bermed Excavation Using Back Analysis (역해석을 통한 소단굴착에 따른 흙막이 벽체변위의 매개변수 연구)

  • Lee, Myoung-Han;Kim, Tae-Hyung
    • Journal of the Korean Geosynthetics Society
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    • v.14 no.4
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    • pp.23-33
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    • 2015
  • Together with the wall stiffness, a berm has the role of deciding the stability of a temporary retaining wall before structure installation after excavation. Especially in case of loose or soft soil excavated ground, the role of berm is very important. In this study, the measurement data obtained from the temporary retaining wall in the bermed excavation site in urban and numerical analysis are used to investigate the effects of berm's dimension (width and slope), excavation depth and ground property on the maximum horizontal displacement of the temporary retaining wall. The measurement data indicated that the wall displacement varied to the berm's width. That is, as the berm width decreased, the wall displacement increased. As a result of numerical analyses, the maximum wall displacement increased as slope increased and berm width decreased. This means that the berm is effectively restrained to the wall displacement. As excavation depth increased, the effect of berm's slope and width increased. In case of the same berm condition, the wall displacement restrained as ground property increased.

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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Effect of seismic acceleration directions on dynamic earth pressures in retaining structures

  • Nian, Ting-Kai;Liu, Bo;Han, Jie;Huang, Run-Qiu
    • Geomechanics and Engineering
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    • v.7 no.3
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    • pp.263-277
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    • 2014
  • In the conventional design of retaining structures in a seismic zone, seismic inertia forces are commonly assumed to act upwards and towards the wall facing to cause a maximum active thrust or act upwards and towards the backfill to cause a minimum passive resistance. However, under certain circumstances this design approach might underestimate the dynamic active thrust or overestimate the dynamic passive resistance acting on a rigid retaining structure. In this study, a new analytical method for dynamic active and passive forces in c-${\phi}$ soils with an infinite slope was proposed based on the Rankine earth pressure theory and the Mohr-Coulomb yield criterion, to investigate the influence of seismic inertia force directions on the total active and passive forces. Four combinations of seismic acceleration with both vertical (upwards or downwards) and horizontal (towards the wall or backfill) directions, were considered. A series of dimensionless dynamic active and passive force charts were developed to evaluate the key influence factors, such as backfill inclination ${\beta}$, dimensionless cohesion $c/{\gamma}H$, friction angle ${\phi}$, horizontal and vertical seismic coefficients, $k _h$ and $k_v$. A comparative study shows that a combination of downward and towards-the-wall seismic inertia forces causes a maximum active thrust while a combination of upward and towards-the-wall seismic inertia forces causes a minimum passive resistance. This finding is recommended for use in the design of retaining structures in a seismic zone.

Evaluation of PBD as Horizontal Drains of Soilbag Retaining Wall (토낭 보강토 옹벽의 수평 배수재로서 PBD의 적용성 평가)

  • Shin, Eun-Chul;Lee, Myung-Shin;Kim, Sung-Hwan
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.2
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    • pp.35-42
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    • 2013
  • Recently, construction of reinforced earth structure using geosynthetics has been increased because it has advantages such as construction efficient, cost effectiveness and appearance aspect against existing gravity or cantilever retaining wall. However due to the climate change in Korea excessive inflow of ground water and surface water from heavy rainfall could affect the stability of reinforced retaining wall seriously. So the discharge capacity of drains should be evaluated by using experimental method in the design of reinforced earth wall. In this study, instead of concrete block used in most of the retaining wall, eco-friendly porous soilbag was used. This paper describes the test method and result of the laboratory testing for determination of discharge capacity utilizing PBDs.

Finite Element Analysis of Engineering Restoration of Dry Stone Wall Foundations (석조문화재 기초부의 공학적 복원을 위한 유한요소법 해석)

  • Kim, Sung-Su;Jung, Young-Hoon;Kim, Soo-Il;Lee, Kwang-Wu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.1130-1141
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    • 2010
  • Even though a number of historic structures in Korea need to be repaired, an intensive research on their engineering performance has rarely been investigated. Herein, we attempted to provide a methodological approach via the explicit finite element analysis to investigate geotechnical aspect of the performance of the dry-stone wall structures. To do so, we summarized relevant literature on the world-wide historic stone structures as well as its analysis in terms of modern geotechnical engineering. The method of the explicit finite element analysis has been briefly summarized. The numerical results on an idealized block structure show that the displacement of blocks and the distribution of earth pressure is different from the conventional theory of the retaining wall because of the discrete nature of the dry-stone wall structure.

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A study on the Remote Control System for Measuring Gradient of temporary earth retaining structure (흙막이 가시설 구조물의 무선원격계측관리시스템에 관한 연구)

  • Woo, Jong-Yeol;Hong, Seong-Wook;Kim, Sang-Won;Seo, Yong-Chil;Shin, Chan-Ho
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2011.05b
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    • pp.49-52
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    • 2011
  • This study concerned with the retention structures or inverted temporary building for displacement measurement in the underground soil after drilling a vertical tilt sensor attached to the vertical distance required to maintain a real-time measurement and management in order to install the wireless measuring devices installed in the field through remote control and management program for the safety of retaining structures temporary building be found on the internet in real time temporary building the retention is to develop a safety management system. And based on this technology to monitor the future status of the various structures possible to add a variety of sensors and Life Cycle Prediction of the structure and needs to evolve into intelligent systems and wireless networks using wireless communications infrastructure systems based on expanding domestic market penetration by developing instrumentation pioneer in overseas markets as well as the activation can also be judged.

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The Application of KOESWall System as a Temporary Structure (임시구조물로서 분리형 보강토 옹벽의 적용사레)

  • 김영윤
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.09a
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    • pp.53-58
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    • 2000
  • The KOESWall system that minimizes the horizontal deformation of reinforced wall effectively was developed bt E&S Eng. Co., Ltd. in 1999. Due to its systematical feature i.e. isolated construction method. KOESWall system is able to use as temporary structures more economically without the facing block. In this report, it is shown that the case history of KOESWall as a temporary soil retaining structure and the field measuremnets.

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Permanent Basement Wall Convergence Method Using a PHC Pile (PHC 파일을 이용한 영구벽체 융합 공법)

  • Ryu, Soo-Hyun
    • Journal of the Korea Convergence Society
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    • v.6 no.6
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    • pp.163-169
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    • 2015
  • This study was intended to suggest a new-concept construction method of permanent basement wall combined with earth retaining wall by using PHC piles to overcome the disadvantages of conventional CIP methods or the like which have been used just for earth retaining walls during field construction, and to determine its applicability. PHC piles are characterized by the reliable quality attributed to prefabrication (shop fabrication) as well as superior concrete strength and prestressing steel strength to that of CIP in the aspect of materials, and also higher bending moment than that of CIP in the aspect of structure.

Determination of active failure surface geometry for cohesionless backfills

  • Altunbas, Adlen;Soltanbeigi, Behzad;Cinicioglu, Ozer
    • Geomechanics and Engineering
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    • v.12 no.6
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    • pp.983-1001
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    • 2017
  • The extent by which economy and safety concerns can be addressed in earth retaining structure design depends on the accuracy of the assumed failure surface. Accordingly, this study attempts to investigate and quantify mechanical backfill properties that control failure surface geometry of cohesionless backfills at the active state for translational mode of wall movements. For this purpose, a small scale 1 g physical model study was conducted. The experimental setup simulated the conditions of a backfill behind a laterally translating vertical retaining wall in plane strain conditions. To monitor the influence of dilative behavior on failure surface geometry, model tests were conducted on backfills with different densities corresponding to different dilation angles. Failure surface geometries were identified using particle image velocimetry (PIV) method. Friction and dilation angles of the backfill are calculated as functions of failure stress state and relative density of the backfill using a well-known empirical equation, making it possible to quantify the influence of dilation angle on failure surface geometry. As a result, an empirical equation is proposed to predict active failure surface geometry for cohesionless backfills based on peak dilatancy angle. It is shown that the failure surface geometries calculated using the proposed equation are in good agreement with the identified failure surfaces.

Applicability of Pseudostatic Analysis for the Seismic Design of Temporary Retaining Structures in a Deep Excavation (흙막이 가시설 내진설계를 위한 등가정적해석의 유효성 분석)

  • Yu, Sang-Hwa;Kim, Dong-Chan;Kim, Jongkwan;Han, Jin-Tae
    • Journal of the Korean Geotechnical Society
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    • v.39 no.9
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    • pp.35-50
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    • 2023
  • A preliminary study is conducted to develop seismic design guidelines for temporary retaining structures in a deep excavation. The study involved a comprehensive literature review of the seismic design standards applied domestically and internationally, as well as various methods to calculate seismic earth pressure for pseudostatic analysis. The FLAC 2D, a two-dimensional finite difference analysis program, was utilized to perform pseudostatic analysis using the Semirigid pressure method, Wood method, and Mononobe-Okabe method. The resulting analysis data for the wall moment and axial force of the strut were compared with the dynamic analysis outcomes to evaluate the applicability of pseudostatic analysis. The Semirigid pressure method predicted the most reasonable moment for Stiff walls experiencing horizontal displacements up to 0.4%H. Predicting the axial force of the strut exactly was challenging because the pseudostatic analysis cannot consider dynamic soil-structure interaction; however, it is deemed available for conservative preliminary review to ensure safety.