• Title/Summary/Keyword: Soil Embankment

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Damage to earth structures by the 2004 Niigata-ken Chuetsu earthquake in Japan and their rehabilitation works

  • Koseki, Junichi;Tsutsumi, Yukika
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.10a
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    • pp.430-433
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    • 2006
  • Damage to earth structures for roads, railways and residential areas, as well as dams and river levees, during the 2004 Niigata-ken Chuetsu earthquake in Japan, and their rehabilitation works are overviewed. Several influential factors are pointed out, such as a) heavy rainfall preceding the earthquake, b) large aftershocks, c) geological conditions for subsoil including existence of liquefiable layers, d) compaction degrees for embankment, and e) drainage capacity from subsoil/embankments. It is also reported that, in the reconstruction works of damaged roads and railways, preferred use of geogrid-reinforced soil retaining walls was implemented.

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Comparisons of Empirical Methods with Numerical Analysis on Lateral Flow in Soft Soils (측방유동에 관한 경험식 및 수치해석의 비교)

  • Kim Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.4
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    • pp.665-670
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    • 2006
  • In this paper, the results of empirical methods and the numerical analysis were compared and investigated on the lateral displacement due to embankment in soft soil. The empirical methods gave different results so the possibility of lateral displacement could not be determined only by the empirical methods. The numerical analysis could be used so effectively that its result showed useful lateral and vertical displacements with depth and distance.

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An Analysis on the Deformation of Clayey Foundation Using Elasto-Viscoplastic Model (${\cdot}$粘塑性構成式을 使用한 粘性土地盤의 變形解析)

  • Lee, Moon-Soo
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.34 no.2
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    • pp.60-72
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    • 1992
  • This study aims at predicting the behavior of saturated soft clayey foundation subjected to earth structure loads such as tidal dike, embankment etc. by using Biot's consolidation equation coupled with elasto-viscoplastic constitutive model. To validate the computer program developed b author, a case study was performed for the site of Kwang-yang steel works improved by sand drain, where since the beginning of the works, field measurements(settlement, lateral displacement and excess pore water pressure) had been accurately achieved. Comparisons between numerical results and observation values were carried out. The main results obtained are summarized as follows : 1. Settlement and lateral displacement between numerical and observation values show satisfactory accordance. 2. As for the exess pre water pressure, numerical results appear to be larger than observation values, which may be due to the existence of sand seams which were not found during soil investigation. 3. Useful data available for failure prediction of soft foundation can be secured by examining lateral displacement, settlement, exess pore water pressure and stress paths.

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A Study on Seismic Stability of Embankment Structure by Numerical Modeling (수치해석을 통한 제방 구조물의 내진 안정성에 관한 연구)

  • Shin, Eun-Chul;Lee, Seung-Taek;Kang, Hyoun-Hoi;Ryu, Byung-Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09b
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    • pp.186-191
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    • 2010
  • Recently, it has been reported that number of earthquakes was rapidly increased in the Korean Peninsula. According to the interest of seismic analysis, most of construction design must ensure the stability of structure against risks due to earthquake. Therefore, the ground reinforcement and application of seismic standards is necessary and the new structures must secure a stability about Earthquake under the Korea Seismic Analysis Standards. In this study, the 2D numerical analysis was performed to confirm a seismic stability and analysed that behavior of ground and dykes. The numerical seismic response analyses for dykes and its foundation soil were conducted with considering earthquake modes of short-period and long-period, and artificial seismic wave.

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Decision Making Model for Optimal Earthwork Allocation Planning (최적 토량배분 계획을 위한 의사결정 모델)

  • Gwak, Han-Seong;Seo, Byoung-Wook;Lee, Dong-Eun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.162-163
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    • 2016
  • This paper presents a mathematical model for optimizing earthwork allocation plan that minimizes earthwork cost. The model takes into account operational constraints in the real-world earthwork such as material-type (i.e., quality level of material) and quantities excavated from cut-sections, required quality of material and quantities for each embankment layer, top-down cutting and bottom-up filling constraints, and allocation orders. These constraints are successfully handled by assuming the rock-earth material as the three dimensional (3D) blocks. The study is of value to project scheduler because the model identifies the optimal earth allocation plan (i.e., haul direction (cut and fill pairs), quantities of soil, type of material, and order of allocations) expeditiously and is developed as an automated system for usability. It is also relevant to estimator in that it computes more realistic earthworks costs estimation. The economic impact and validity of the mathematical model was confirmed by performing test cases.

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A Study on Replacement Behaviour of Soft Soil by Centrifuge Modelling Test (원심모형시험을 통한 연약지반의 강제치환거동 연구)

  • 이승원;이영남
    • Journal of the Korean Geotechnical Society
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    • v.16 no.6
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    • pp.141-151
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    • 2000
  • 본 연구에서는 토사나 사석을 이용하여 자체를 축조하는 과정에서 발생하는 연약지반의 강제치환거동을 연구하기 위하여 다양한 시험조건에 대한 원심모셩을 수행하였다. 제체축조에 따른 연약지반의 강제치환거동은 제체의 성토시공방법, 성토재의 입경, 연약지반의 종류와 강도 등에 따라 맣은 차이를 보였는데, 특히 성토과정 중에 발생하는 과잉간극수압의 크기와 밀접한 상관관계를 보였다. 급속시공인 경우에 연약지반의 파괴영역은 회적으로 확대되고 성토사면의 기울기는 완만해졌으며, 성토재의 입경이 클수록 치환깊이가 증가하고 성토사면의 기울기가 급하게 형성되었다. 그리고 동일점토에서는 지반의 강도가 클수록 치환량이 적었지만, 점토의 종류가 다른 경우에는 지반내 발생하는 과잉간극수압의 크기와 소산성조에따라 치환거동이 많은 영향을 받는 것으로 나타났다.

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A Study on the Creep Parameters of Ansan Marine Clay (안산지역 해함점토의 크리프 정수에 관한 연구)

  • 정형식;안상로
    • Geotechnical Engineering
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    • v.9 no.4
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    • pp.93-102
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    • 1993
  • Soil structures which are constructed over the soft ground settle continuously by the self-weight of embankment for a long time. It is because of timetependent behaviours . consolidation and creep occurring simultaneously. This paper tries to determine the required parameters for analysis of the creep behaviour in marine clays and studied the effect of the confining stress and stress level on the creep parameters . As a result, it presents an equation for the determination of creep parameters according to stress level considering that elastic modulus El and creep parameter f are found to be affected by the applied stress level.

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Study on Application of Criteria of Lateral Flow in Soft Soils (측방유동 판정기준의 적용성 연구)

  • Chae, Young-Soo;Moon, Han-Joong;Kim, Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.2
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    • pp.219-223
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    • 2006
  • In this paper, the criteria of the lateral displacement in soft soil due to embankment were evaluated. The lateral displacement was measured at a pier structure in a new harbor construction site, and the measurement was compared with the criteria. The results by the measurement such as the critical pressure causing lateral movement in terms of undrained strength, the lateral movement index by Japan Highway Co., the lateral displacement index by Japan Construction Ministry, the modified index by Korean Highway Co. were estimated to be lower than the respective index values.

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Dynamic-stability Evaluation of Unsaturated Road Embankments with Different Water Contents (함수비에 따른 불포화 도로성토의 동적 안정성 평가)

  • Lee, Chung-Won;Higo, Yosuke;Oka, Fusao
    • Journal of the Korean Geotechnical Society
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    • v.30 no.6
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    • pp.5-21
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    • 2014
  • It has been pointed out that the collapses of unsaturated road embankments caused by earthquake are attributed to high water content caused by the seepage of the underground water and/or the rainfall infiltration. Hence, it is important to study influences of water content on the dynamic stability and deformation mode of unsaturated road embankments for development of a proper design scheme including an effective reinforcement to prevent severe damage. This study demonstrates dynamic centrifugal model tests with different water contents to investigate the effect of water content on deformation and failure behaviors of unsaturated road embankments. Based on the measurement of displacement, the pore water pressure and the acceleration during dynamic loading, dynamic behavior of the unsaturated road embankments with about optimum water content and the higher water content than the optimum one have been examined. In addition, an image analysis has revealed the displacement field and the distributions of strains in the road embankment, by which deformation mode of the road embankment with higher water content has been clarified. It has been confirmed that in the case of higher water content the settlement of the crown is large mainly owing to the volume compression underneath the crown, while the small confining pressure at the toe and near the slope surface induces large shear deformation with volume expansion.

Grouting Injection Effectiveness of a Permeable Compacting Grout using Permeable Compaction Type Packer (침투다짐형 팩커를 이용한 침투다짐 그라우트의 주입 효과)

  • Park, Sung-Yong;Shim, Houng-Gen;Kang, Hee-Jin;Lim, One-Bin;Kim, Yong-Seong
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.2
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    • pp.149-158
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    • 2017
  • Permeating injection is commonly known as an ideal type of injection in grouting reservoir embankment, yet often-combined permeating and fracturing injection grouting operation can disturb the original soil. A grouting method has been regarded as effective and developed to ameliorate the possible disturbance problem. It involves compaction grouting with low expansive pressure near the injection hole and repetitive injection and compaction with grout material that allows ideal permeating injection. This thesis develops Hybrid Grout (ie. HG grout) that allows various application in any ground condition combined together, has high fineness and low viscosity, and expands permeation injection to silty sand. It researches on the injection effect of permeable compaction grout which is done with PC packer and is a combination of HG grout and expansion agent to obtain permeation compaction effect on the area near grout injection spot by developing Permeable Compaction Type Packer(ie. PC packer). As the developed PC packer, HG grout, and and expansion agent (HI-E) are applied to reservoir embankment reinforcement grouting, possibile permeation compaction effect that satisfies reservoir embankment grouting standard is confirmed according to the research.