• Title/Summary/Keyword: Geosynthetic-soil

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Heat Exchange Drainage Method Induced Bearing Capacity Characteristic (열유도 배수공법이 적용된 지반의 하중지지 특성)

  • Shin, Seung-min;Sin, Chun-won;Yoo, Chung-Sik
    • Journal of the Korean Geosynthetics Society
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    • v.16 no.2
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    • pp.159-164
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    • 2017
  • This paper presents the results of an investigation into the thermo-hydromechanical response of weathered granite soil. The effect of forced change temperature and relative humidity at the soil layer boundaries were monitored during heating. A series of load settlement test were performed on layers of compacted, unsatureated weathered granite soil with geosynthetic embedded at mid height before and after application of heat exchanger to the base of the soil layers. The results from this study indicated the potential for using embedded heat exchangers for the mechanical improvement of geotechnical systems incorporating weathered granite soil.

A review on uplift response of symmetrical anchor plates embedded in reinforced sand

  • Niroumand, Hamed;Kassim, Khairul Anuar
    • Geomechanics and Engineering
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    • v.5 no.3
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    • pp.187-194
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    • 2013
  • The most soil anchor works have been concerned with the uplift problem on embedded in non-reinforced soils under pullout test. Symmetrical anchor plates are a foundation system that can be resisting tensile load with the support of around soil in which symmetrical anchor plate is embedded. Engineers and authors proved that the uplift response can be improved by grouping the symmetrical anchor plates, increasing the unit weight, embedment ratio and the size of symmetrical anchor plates. Innovation of geosynthetics in the field of geotechnical engineering as reinforcement materials found to be possible solution in symmetrical anchor plate responses. Unfortunately the importance of reinforcement in submergence has received very little attention by researchers. In this paper, provision of tensile reinforcement under embedded conditions has been studied through uplift experiments on symmetrical anchor plates by few researchers. From the test results it has been showed that the provision of geogrid reinforcement system enhances the uplift response substantially under uplift test although other results are such as increase the ultimate uplift response of symmetrical anchor plate embedded using geosynthetic and Grid Fixed Reinforced (GFR) and symmetrical anchor plate improvement is very dependent on geosynthetic layer length and increases significantly until the amount of beyond that further increase in the layer length does not show a significant contribution in the anchor response.

Long-Term Hydraulic Conductivity and Cation Exchange of a Geosynthetic Clay Liner (GCL) Permeated with Inorganic Salt Solutions

  • Jo, Ho Young;Benson, Craig H.;Edil, Tuncer B.
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.09a
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    • pp.59-62
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    • 2004
  • Hydraulic conductivity tests were conducted on a geosynthetic clay liner (GCL) for more than 2.5 yr using inorganic salt solutions to evaluate how the long-term hydraulic conductivity is affected by cation concentration and valence. Only small changes (i.e., $\leq$ 2X) in hydraulic conductivity (K) occurred during the test duration when the permeant solution was deionized (DI) water or 100 mM KCl and NaCl solutions. For weak CaCl$_2$ solutions ($\leq$ 20 mM), the hydraulic conductivities initially (< 0.2 yr) were comparable to the hydraulic conductivity obtained with DI water, but gradually increased by a factor of 2 to 13 over a period of nearly 2 yr. In contrast, the GCL permeated with strong CaCl$_2$ solutions ($\geq$ 50 mM) reached equilibrium nearly immediately, with a hydraulic conductivity approximately 2 orders of magnitude higher than the hydraulic conductivity to DI water.

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Time-Dependent Deformation Characteristics of Geosynthetic-Reinforced Soil Using Plane Strain Compression Tests (평면변형압축시험을 이용한 보강토의 시간 의존적 변형 특성 연구)

  • Yoo Chung-Sik;Kim Sun-Bin;Lee Bong-Won
    • Journal of the Korean Geotechnical Society
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    • v.21 no.10
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    • pp.85-97
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    • 2005
  • Despite a number of advantages of reinforced earth walls over conventional concrete retaining walls, there exist concerns over long-term residual deformation when subjected to repeated and/or cyclic loads, especially when used as part of permanent structures. In view of these concerns, in this paper time-dependent deformation characteristics of geosynthetic reinforced soil under sustained and/or repeated loads were investigated using a series of plane strain compression tests on geogrid reinforced weathered granite soil specimens. The results indicate that sustained or repeated loads can yield appreciable magnitudes of residual deformations, and that the residual deformations are influenced not only by the loading characteristics but by the mechanical properties of geogrid. It is also found that the preloading technique can be effectively used in controlling residual deformations of reinforced soils subjected to sustained and/or repeated loads.

Behavior of Geosynthetic Reinforced Wall with Heat Induce Drainage Method During Rainfall (열유도 토목섬유 배수공법이 적용된 보강토 옹벽의 강우시 거동 특성)

  • Shin, Seung-min;Sin, Chun-won;Yoo, Chung-Sik
    • Journal of the Korean Geosynthetics Society
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    • v.15 no.1
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    • pp.11-19
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    • 2016
  • This paper presents the results of a scale model test to the effect of heat exchanger drainage method in retaining wall of weathered granite soil. Purpose to rise in the temperature of the heat wires inside the weathered granite soil is preventing the collapse of the retaining wall and drainage smoothly moved to the drainage layer. Especially using a spray gun to simulate the rainfall since the rainfall drainage work is important for the rainfall effect on soil, find the difference about displacement of the retaining wall, change of volume water content, drainage, earth pressure and change in the strain of the geosynthetic was effected to heat exchanger within the soil. The result from applying the heat exchanger method decreased the earth pressure and displacement of the wall and increased drainage of water.

Dynamic Behavior of Offshore Waste Landfill Revetment with Geosynthethic-Soil Interface (토목섬유 접촉면을 포함한 해상 폐기물처분장 호안구조물의 동적 거동)

  • Kwak, Chang Won;Oh, Myoung Hak;Park, Inn Joon;Jang, Dong In
    • Journal of the Korean Geotechnical Society
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    • v.33 no.12
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    • pp.141-150
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    • 2017
  • Geosynthetics are generally utilized to restrain the leakage of leachate and other contaminants during the construction of offshore waste landfill. Therefore, geosynthetic-soil interface is formed inevitably. In this study, 2 dimensional numerical analysis is performed to assess the dynamic behaviour of the offshore waste landfill including geosynthetic-soil interface. Offshore waste landfill can be divided into rubble mound revetment and retaining wall types and analyzed on each type. Effective stress analysis is conducted to consider the variation of pore water pressure and axial force and shear displacement of the interface are compared based on the characteristics of seismic frequency. Consequently, retaining wall type demonstrates more stable behavior against liquefaction potential and favorable forces and shear displacement.

Integral Bridge System with Geosynthetic-Reinforced Backfill

  • Tatsuoka, Fumio
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.39-52
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    • 2007
  • A new type bridge combining an integral bridge and a pair of geosynthetic-reinforced soil (GRS) retaining walls having full-height rigid (FHR) facings, called the GRS integral bridge, is proposed. The geosynthetic reinforcement layers are connected to the FHR facings (i.e., RC parapets) that are integrated with a girder without using any girder-support. GRS integral bridges are basically much more cost-effective in construction and long-term maintenance while having a much higher seismic stability than conventional-type bridges having a girder via movable and fixed supports on a pair of cantilever abutments. GRS integral bridges are better than bridges using GRS retaining walls as abutments and also than conventional integral bridges with unreinforced backfill. To validate the above, a series of static cyclic lateral loading tests of the facing and a series of shaking table tests were performed on smallscaled models of different bridge types.

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A Study on the Improvement Mechanical Properties of Geosynthetic Interface (토목섬유 접촉면의 역학적 특성 개선에 관한 연구)

  • Nam, Yong;Kim, Gwangho;Kwon, Jeonggeun;Im, Jongchul;Seo, Jeochan
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.3
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    • pp.23-32
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    • 2010
  • In this study, Generally sandbag was used to reinforce slope or restore levee by using the in-situ material. To increase shear strength of sandbag, the Velcro system was effective for geosynthetic interface and make up for the weakness of shear strength between sandbag to sandbag. In this study, shear properties of geosynthetic-geosynthetic and geosynthetic-soil were evaluated from large scale direct shear tests. The cohesion and the angle of internal friction of each interface was evaluated. And laboratory model tests were performed to compare strength of reinforcement with strength of none reinforcement. As a result of this study, the cohesion and the angle of internal friction of each interface was increased, especially the cohesion was increased more than the angle of internal friction. Also according to the result of model test, the bearing capacity was increased by 20%.

Model to Determine Long-term Allowable Strength of Geosynthetics Reinforcements Considering Strain Compatibility (변형률 적합성을 고려한 토목섬유 보강재의 장기허용강도 결정 모델)

  • Jeon, Han-Yong;Yuu, Jung-Jo;Mok, Mun-Sung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1580-1587
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    • 2005
  • To calculate the long-term allowable strength of geosynthetic reinforcement, replacement method was recommended. The isochronous creep curve by S. Turner was used to define the relation between creep strain and allowable strength. In isochronous curve at given time, one can read the allowable strength at allowable creep strain. The allowable strain gets from specification by directors or manufacturers according to the allowable displacement of reinforced structures. The allowable strength can be determined in relation to the allowable horizontal displacement each structures case by case. The effect of install damage on isochronous behaviors of geosynthetic reinforcement was little. In previous study, install damage increase the creep strain slightly. And the degradation was not identified. But it is supposed that degradation increase the creep strain. In conclusion, The recommended model to determine long-term allowable strength of geosynthetic reinforcements considering tensile deformation of reinforcement and soil is fit for proper, correct and economic design for reinforced earth walls.

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