• Title/Summary/Keyword: Reinforced soil

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Research about Application Possibility of Afforestation Reinforced Soil Steep Slope by Nonwoven Geotextile (부직포를 활용한 급경사 녹화보강토공법의 적용 가능성에 관한 연구)

  • Cho, Yong-Seong;Koo, Ho-Bon;Lee, Choon-Kil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4C
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    • pp.239-245
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    • 2006
  • The steep slopes have been increased of new roads, industrial site development and large scale residential development. The preservation administration and steep slope construction are currently investigated by many researchers in Korea. However, concrete retaining wall or reinforced soil (i.e. Block or Pannel) are being applied for the steep slope, which results in the front face form of the structure being limited. This research investigates the method that can make up afforestation environment-friendly circumstances during the construction of steep slope structure. It is considered that steep slope reinforced structure would be possible based on the monitoring results about earth pressure, horizontal displacement and consolidation quality generated during the construction of whole constructing reinforced structure. Also, there no problems in grassy surface, drainage, and deformation in spite of rainy season after construction period and until now. So that the seeding soil layer surface reinforced soil method could be adopt for steep slope reinforced structure and others.

A Case Study of The Collapsed Reinforced-Soil Retaining Wall (보강토옹벽의 사고사례에 관한 연구)

  • Yoo, Chung-Sik;Jung, Hyuk-Sang;Lee, Soung-Woo
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.2
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    • pp.13-21
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    • 2004
  • This paper deal with the analysis of the causes about case of collapsed reinforced-soil retaining wall. The analysis of the cause was carried through experimentation, slop stability analysis and literature study. The experimentation treated the large direct shear test, the hydraulic conductivity test and the other basic test through backfill extraction from collapsed reinforced-soil retaining wall. The ultimate tensile strength was established by rib tensile strength test of geogrid. The analysis of internal and external stability of reinforced-soil retaining wall was performed on the basis of parameters. The result of analysis, reinforced-soil retaining wall and the slope at the dry season are stable. However, the factors that fine-grained soil at hydrometer test exceed the standard of the design, rainfall duration is too long at the time of collapse and monthly pricipitation is heavy, which are causes of the collapse.

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Long-Term Behavior of Geogrid Reinforced Soil Abutment - A Numerical Investigation (지오그리드 보강토 교대의 장기거동에 관한 수치해석 연구)

  • Yoo, Chung-Sik;Jeon, Han-Yong
    • Journal of the Korean Geotechnical Society
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    • v.27 no.1
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    • pp.65-76
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    • 2011
  • This paper presents the results of a numerical investigation on the long-term behavior of geosynthetic reinforced soil abutment. The investigation was carried out aiming at identifying the governing mechanisms of the long-term deformation of geosynthetic-reinforced soil abutment subjected to sustained loads during service life. A numerical modeling strategy was first established using the Singh-Mitchell creep model and the power law model, respectively, for the backfill and the geosyntehtic reinforcement. A parametric study on the creep properties of the backfill and the geosynthetic reinforcement was then conducted. The results indicated that a geosynthetic reinforced soil structure backfilled with marginal soil may exhibit substantial long-term deformation due to the creep effects caused by both the backfill soil and the geosynthetic reinforcement, the magnitude of which depends largely on the creep properties. This paper highlights the importance of considering the creep effect on load supporting geosynthetic reinforced soil structures when the long-term serviceability requirement is of prime importance.

Instrumentation of A Two-Level of Soil-Reinforced Segmental Retaining Wall (계단식 지오그리드 보강토 옹벽의 계측)

  • 유충식;정혁상
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.697-704
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    • 2002
  • This paper presents the results of instrumentation of a two-level of soil-reinforced segmental retaining wall. Instrumentation items include the lateral wall displacements and the geogrid strains at several locations. The instrumentation is still long carried in order to examine long-term behavior. The result indicate that the upper wall has a significant effect on the behavior of the lower wall doubling the wall moved. The wall also exhibits significant post-construction movements that had ceased several months after the wall completed. The implication of the findings from this study was discussed in great detail.

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Numerical Modeling of Long-Term Behavior of Geosynthetic Reinforced Soil Wall used in Bridge Abutment (보강토 교대 옹벽의 장기 거동에 대한 수치 모델링)

  • Yoo, Chung-Sik
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.4
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    • pp.105-112
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    • 2011
  • This paper presents the numerical modelling technique for modeling the time-dependent behavior of geosynthetic reinforced soil wall under a sustained load. The applicability of power law-based creep models for modeling the creep deformations of geogrid and reinforced soil was first examined. The modeling approach was then used to simulate the long-term performance of a geosynthetic reinforced soil wall used in a bridge abutment. The results indicated that the power law-based models can be effectively used for modelling the long term behavior of geosynthetic reinforced walls under sustained loading. In addition, it was shown that, when using creep deformation susceptible backfill soils, the abutment wall and the sill beam may experience deformations exceeding allowable limits. Practical implications of the findings from this study are discussed in great detail.

Probabilistic bearing capacity of strip footing on reinforced anisotropic soil slope

  • Halder, Koushik;Chakraborty, Debarghya
    • Geomechanics and Engineering
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    • v.23 no.1
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    • pp.15-30
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    • 2020
  • The probabilistic bearing capacity of a strip footing placed on the edge of a purely cohesive reinforced soil slope is computed by combining lower bound finite element limit analysis technique with random field method and Monte Carlo simulation technique. To simulate actual field condition, anisotropic random field model of undrained soil shear strength is generated by using the Cholesky-Decomposition method. With the inclusion of a single layer of reinforcement, dimensionless bearing capacity factor, N always increases in both deterministic and probabilistic analysis. As the coefficient of variation of the undrained soil shear strength increases, the mean N value in both unreinforced and reinforced slopes reduces for particular values of correlation length in horizontal and vertical directions. For smaller correlation lengths, the mean N value of unreinforced and reinforced slopes is always lower than the deterministic solutions. However, with the increment in the correlation lengths, this difference reduces and at a higher correlation length, both the deterministic and probabilistic mean values become almost equal. Providing reinforcement under footing subjected to eccentric load is found to be an efficient solution. However, both the deterministic and probabilistic bearing capacity for unreinforced and reinforced slopes reduces with the consideration of loading eccentricity.

Effects of Surface Loading on the Behavior of Soil-Reinforced Segmental Retaining Walls (상재하중이 블록식 보강토 옹벽의 거동에 미치는 영향)

  • 유충식;김주석
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.109-116
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    • 2000
  • This paper presents the results of investigation on the effects of surface loading on the performance of soil-reinforced segmental retaining walls using the finite element method of analysis. A parametric study was performed by varying location of surface loading. The results of the analyses indicate that the increment of the reinforcement tensile load due to the presence of surface load may be significantly over-estimated when using the conventional approach. Furthermore, the external stability should be carefully examined when a surface loading is present just outside the reinforced soil zone. The implications of the findings from this study to current design approaches are discussed in detail.

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Numerical Modelling of Reinforced Soil Slopes Under Railway Load (열차하중을 받는 토목섬유 보강사면의 수치해석)

  • Jung, Young-Hoon;Lee, Il-Wha;Jang, Ki-Soo;Yoo, Seung-Joon;Lee, Su-Hyung
    • Journal of the Korean Society for Railway
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    • v.9 no.6 s.37
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    • pp.753-760
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    • 2006
  • This paper presents the procedure and results of the numerical modelling that was carried out to investigate the stability of reinforced soil slopes under dynamic railway load. The two-dimensional explicit dynamic finite element method (ABACUS) was used to carry out the numerical analyses. To simulate the railway load, the top surface of the embankment was excited by the uniform distributed load whose frequency and magnitude was estimated by the measured railway acceleration during train passing. The embankment displacements and geogrid axial forces were analyzed to evaluate the stability of reinforced soil slopes under the dynamic train load.

Variation of Unit Weight and Compressive Strength by Long-Term Dry Shrinkage of Reinforced Soil Mixture (장기적 건조수축에 의한 보강혼합토의 단위 중량 및 압축강도 분석)

  • 이상호;차현주;장병욱
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.42 no.6
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    • pp.90-97
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    • 2000
  • In this study, the variation of unit weight and unconfined compressive strength were investigated, calcium carbonate, quicklime, portland cement, 19mm length monofilaments and fibrillated fiber were used as reinforcement materials. And calcium chloride was added to cement and calcium carbonate reinforced soil mixture in order to accelerate setting and hardening speed. It appears that unit weight is highest in calcium carbonate reinforced soil mixture with mixing rate of 9%. According to increasing the amount of fiber in soil mixture, the unit weight decreased. It shows that the more the amount of monofilament fiber is added in soil mixture, the higher the compressive strength is, but the compressive strength is decreased in fibrillated fibrillated fiber added soil mixture with more than 1.0% of mixing rate.

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Development of design method using Limit Equilibrium Method applying to vertical excavation reinforcing by soil-nailing (쏘일네일 보강 연직굴착면의 한계 평형법을 이용한 설계기법 개발)

  • Lee, Seom-Beom;Lee, In;Yun, Bae-Sik;Kim, Hong-Taek
    • Journal of the Korea Construction Safety Engineering Association
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    • s.47
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    • pp.56-62
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    • 2008
  • In order to apply the Limit Equilibrium Method generally used for the slope stability analysis to the vertical excavation walls reinforced by soil-nailing, in this study, the Limit Equilibrium Method for the temporary shoring facilities reinforced by soil-nailing was proposed, which is based on the stability for the horizontal displacement. In this study, the relation of the internal friction angles of the ground and the vertical excavation depths was arranged, which is satisfying the stability on the horizontal displacement by using the verification of the Limit Equilibrium Method. And then, the rational reinforcing length of soil-nailing was proposed for the critical areas. In addition, the modified safety ratio satisfying the stability on the horizontal displacement was proposed, when the Limit Equilibrium Method was applied to the vertical excavation walls reinforced by soil-nailing.

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