• Title, Summary, Keyword: Consolidation process

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One-dimensional consolidation analysis of clayey soils based on elasto-viscous liquid model (탄점성압밀방정식을 이용한 점성토의 일차원 압밀 해석에 관한 연구)

  • 염혜선;김지용;정승용;김수삼
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.689-694
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    • 2000
  • The traditional concept after Terzaghi was that consolidation was the dissipation process of pore water pressure compatible to external loading which was generated immediately after the loading. However, a theory of one-dimensional consolidation based on elasto-viscous liquid model proposed by Yoshikuni(1994) explained that the process of primary and secondary consolidation was considered to be not a simple process of dissipation of pore water pressure but a simultaneous process of dissipation and generation by external loading. This study attempts to demonstrate general consolidation behaviour of clayey soils including effects of consolidation history, load increment and thickness of cohesive layer by one-dimensional Finite Difference Method(F.D.M) analysis from the viewpoint of elasto-viscous consolidation theory.

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Influence of Changing Coefficient of Consolidation and Layered Condition on Consolidation Behavior (압밀계수변화 및 지층조건이 압밀현상에 미치는 영향)

  • Jeon, Je-Sung;Koo, Ja-Kap;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.147-157
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    • 2005
  • In this study, consolidation analysis methods reflecting various ground condition and changing coefficient of consolidation with consolidation process are presented. Research activities include development of numerical program consists of two parts considering vertical drainage only and both drainage condition with vertical and radial direction. Also, interface equation of adjacent two layers and function for changing coefficient of consolidation are added to developed program. This paper presents the results from a detailed consolidation analyses, which explores consolidation process with time in varying layered system and changing coefficient of consolidation

REPORT ON CONSOLIDATION-INDUCED SOLUTE TRANSPORT

  • Lee, Jang-Guen
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.140-145
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    • 2010
  • Consolidation in cohesive soils mainly focuses on compressibility of soils, but it affects solute transport in some cases. The consolidation process takes on particular significance for fine grained soils at high water content, such as dredged sediments, but has also been shown to be important for compacted clay liners during waste filling operation. Numerical investigation using CST1 and CST2 was reviewed on consolidation-induced solute transport in this paper, especially with the development of CST2 model, verification by comparing experimental results with numerical simulations, and cases studies regarding transport in a confined disposal facility (CDF) and during in-situ capping. The importance of the consolidation process on solute transport is accessed based on simulated concentration or mass breakthrough curves. Results indicate that neglecting transient consolidation effects may lead to significant errors in transport analyses, especially with soft contaminated cohesive soils undergoing large volume change.

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An experimental procedure for evaluating the consolidation state of marine clay deposits using shear wave velocity

  • Chang, Ilhan;Kwon, Tae-Hyuk;Cho, Gye-Chun
    • Smart Structures and Systems
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    • v.7 no.4
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    • pp.289-302
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    • 2011
  • In marine clay deposits, naturally formed or artificially reclaimed, the evaluation and monitoring of the consolidation process has been a critical issue in civil engineering practices due to the time frame required for completing the consolidation process, which range from several days to several years. While complementing the conventional iconographic method suggested by Casagrande and recently developed in-situ techniques that measure the shear wave, this study suggests an alternative experimental procedure that can be used to evaluate the consolidation state of marine clay deposits using the shear wave velocity. A laboratory consolidation testing apparatus was implemented with bimorph-type piezoelectric bender elements to determine the effective stress-shear wave velocity (${\sigma}^{\prime}-V_s$) relationship with the marine clays of interest. The in-situ consolidation state was then evaluated by comparing the in-situ shear wave velocity data with the effective stress-shear wave velocity relationships obtained from laboratory experiments. The suggested methodology was applied and verified at three different sites in South Korea, i.e., a foreshore site in Incheon, a submarine deposit in Busan, and an estuary delta deposit in Busan. It is found that the shear wave-based experimental procedure presented in this paper can be effectively and reliably used to evaluate the consolidation state of marine clay deposits.

Development of a Prototype Expert System for Intelligent Operation Aids in Rod Consolidation Process (핵연료 밀집공정의 지능적 조업을 위한 전문가시스템 모형의 개발)

  • Kim, Ho-Dong;Kim, Ki-Joo;Yoon, Wan-Ki
    • Nuclear Engineering and Technology
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    • v.25 no.1
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    • pp.1-7
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    • 1993
  • This paper describes a prototype expert system to aid operation in rod consolidation process. The knowledgebase is composed of three database groups and 60 rules with production, and object oriented techniques that correlates database groups. The expert system is designed to track the transitions of nuclear materials through the operation areas of the rod consolidation process, to diagnose current status in any operating conditions, normal and off-normal, and to advise operators to properly recover off-normality. The expert system can give efficient management of nuclear material accountability and process operation in the rod consolidation.

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Elasto-viscoplastic modeling of the consolidation of Sri Lankan peaty clay

  • Karunawardena, Asiri;Oka, Fusao;Kimoto, Sayuri
    • Geomechanics and Engineering
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    • v.3 no.3
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    • pp.233-254
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    • 2011
  • The consolidation behavior of Sri Lankan peaty clay is analyzed using an elasto-viscoplastic model. The model can describe the secondary compression behavior as a continuous process and it can also account for the effect of structural degradation on the consolidation analysis. The analysis takes into account all the main features involved in the process of peat consolidation, namely, finite strain, variable permeability, and the secondary compression. The material parameters required for the analysis and the procedures to evaluate them, using both standard laboratory and field tests, are explained. Initially, the model performance is assessed by comparing the predicted and the observed peat consolidation behavior under laboratory conditions. The results indicate that the model is capable of predicting the observed creep settlements and the effect of layer thickness on the settlement analysis of peaty clay. Then, the model is applied to predict the consolidation behavior of peaty clay under different field conditions. In this context, firstly, the one-dimensional field consolidation of peaty clay, brought about by the construction of compacted earth fill, is predicted. Then, the two-dimensional peat foundation response upon embankment loading is simulated. A good agreement is seen in the comparison of the predicted results with the field observations.

Non-linear Finite Strain Consolidation of Ultra-soft Soil Formation Considering Radial Self-weight Consolidation (방사방향 자중압밀을 고려한 초연약 지반의 비선형 유한변형 압밀거동 분석)

  • An, Yong-Hoon;Kwak, Tae-Hoon;Lee, Chul-Ho;Choi, Hang-Seok;Choi, Eun-Seok
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.495-508
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    • 2010
  • Vertical drains are commonly used to accelerate the consolidation process of soft soils, such as dredged materials. The installation of vertical drain provides a radial drainage path to water in the deposit soil in addition to the vertical direction. An estimation of time rate of settlement is considerably complicated when vertical drains are installed to enhance consolidation process of dredged material because the vertical drains are commonly installed before self-weight consolidation is ceased. In this paper, the vertical drain theory developed by Barron(1948) is applied to analyze the non-linear consolidation behavior considering radial drainage. The overall average degree of self-weight consolidation of the dredged soil under the condition that the water is drained in both radial and vertical directions is estimated using the Carillo(1942) formula. In addition, the Morris(2002) theory and the one-dimensional non-linear finite strain numerical model, PSDDF, are applied to analyze the self-weight consolidation in case of only the vertical drainage is considered. The new analysis approach proposed herein can simulate properly the time rate of the self-weight consolidation of dredged materials that is facilitated with vertical drains.

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Micro-mechanical Modeling of the Consolidation Processes in Titanium Metal Matrix Composites (티타늄금속기 복합재료의 강화공정에 관한 미시역학적 모델링)

  • 김준완;김태원
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.207-210
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    • 2002
  • Metal matrix composites(MMCs) are increasingly attractive for high technology components such as aerospace applications and transportations due to their high strength, stiffness, and toughness. Many processes for fabricating MMCs have been developed, and relatively simple Foil-Fiber-Foil method is usually employed in solid state consolidation processes. During the consolidation processes at high temperature, densification occurs by the inelastic flow of the matrix materials, and the process is coupled with the conditions of pressure, temperature and volume fraction of fiber and matrix materials. This is particularly important in titanium matrix composites, and thus a generic model based on micro-mechanical approaches enabling the evolution of density over time to be predicted has been developed. The mode developed is then implemented into FEM so that practical process simulation has been carried out. Further the experimental investigation of the consolidation behavior of SiC/Ti-6Al-4V composites using vacuum hot pressing has been performed, and the results obtained are compared with the model predictions.

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Analysis of Consolidation Behavior for Dredged Clay with Horizontal Drains (수평배수재가 설치된 준설매립 점토의 압밀 거동 해석)

  • 김수삼;장연수;박정순;오세웅
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.641-648
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    • 2000
  • The horizontal drain method by installing drains horizontally in the ground is often used to expedite the dispersion of pore water and to increase the strength of dredged soft clay under the action of gravity or vacuum. In this study a numerical analysis method is developed to predict the consolidation process of soft ground with horizontal drains. One-dimensional self-weight consolidation theory is extended tn three-dimensions] theory with appropriate boundary conditions of horizontal drains. In the condition of pore water drainage by gravity, the behavior of the dredged clay with horizontal drains is compared with that of the clay without drains. The influence of design factors of drains on consolidation process is also analyzed.

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Automation design of spent fuel rod consolidation

  • Yun, Ji-Sup;Lee, Jae-Sol;Park, Hyun-Soo
    • 제어로봇시스템학회:학술대회논문집
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    • pp.613-618
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    • 1987
  • Rod consolidation is a method of increasing spent nuclear fuel storage capacity by disassembling fuel assemblies thus storing the fuel rods in a tighter array. It involves some basic operations which closely resemble to the material handling of a manufacturing process. But all the operations must be controlled remotely in shielded environment from outside due to the highly radioactive nature of the workpiece. In this study the status of the rod consolidation technology in other countries has been surveyed and a feasibility study for the conceptual design of this process have been made.

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