• Title/Summary/Keyword: Geogrid-reinforced

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Pullout Resistance of Geogrid Reinforced Soil according to Compaction Degree (흙의 다짐도에 따른 인발저항특성 연구)

  • 주재우;김병욱;박종범
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.11c
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    • pp.11-20
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    • 1999
  • The method which makes the soft ground reinforced by using the geogrid, a kind of geosynthetics has been getting popular and its usefulness also has been increased due to reduction in costs, ease of construction and great exterior view, But the study on the frictional characteristics, which is the important factor in design, between reinforcement and soil is insufficient. In this study, compaction degrees were considered through large-scale pullout tests. As a part of studying on estimation of pullout frictional characteristics between soil and geosynthetics, pullout tests were peformed and from the result of pullout tests, pullout frictional parameters between soil and geosynthetics were obtained and pullout behaviors were learned.

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An Experimental Study on Characteristics of Earth Pressure Distribution for Segmental Reinforced Earth Wall (블록형 보강토 옹벽의 토압 특성 연구)

  • 김진만;조삼덕;이정재;백영식
    • Journal of the Korean Geotechnical Society
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    • v.20 no.1
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    • pp.83-90
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    • 2004
  • Retaining walls with reinforced earth have been constructed around the world. The use of reinforced earth is a recent development in the design and construction of earth-retaining structure. It is believed that reinforced retaining wall has some advantages which make construction quite simple basically. It wilt take short construction time relatively, comparing, fur example with reinforced-concrete retaining wall. In addition, low price and easy construction will be good attractive points in practical point of view. In this study, five field-tests monitoring data for lateral pressures on geogrid-reinforced retaining wall have been compiled and evaluated. Based on field-tests it is found that horizontal displacements of the facing was measured to be about 0.19∼0.76% and that the maximum tensile strains of reinforcement was evaluated to be about 0.66∼1.98%. The maximum tensile strains, measured from each site, do not reach 5% of the practical allowable strain of the geogrid. And also it is found that the lateral pressure distributions of reinforced-earth retaining wall are close to a trapezoid shape like a flexible retaining wall system, instead of a theoretical triangular shape.

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.

Site Monitoring and Analysis of the Reinforced Slope with geogrid (지오그리드를 이용한 보강사면의 현장 계측 연구)

  • Kim, Jin-Man;Cho, Sam-Deok;Choi, Bong-Hyuck
    • Journal of the Korean Geosynthetics Society
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    • v.2 no.3
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    • pp.3-9
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    • 2003
  • Geosynthetics as a reinforcing material for earth structures have ever increased due to their excellent economy, fine external appearance, and easy construction. Geogrids are high-strength, orientated-polymer grid structures used to reinforce soil. This paper deals with the construction and sire monitoring for a 5.1m high-reinforcd slope with $75^{\circ}$ steep. The purpose of site monitoring is to evaluate the applicability of reforced slope with geogrid. Full scale field performance during and after construction was monitored by incorporating instrumentation including strain gauges on the geogrid, and horizontal and vertical movements.

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Scour Characteristics of Artificial Reef through Experiment and Numerical Analysis (실내실험 및 수치해석을 이용한 인공어초 세굴 거동 특성 연구)

  • Yun, Daeho;Kim, Yuntae
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.3
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    • pp.23-32
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    • 2019
  • This study investigated the scour characteristics of artificial reef according to unreinforced and reinforced artificial reefs through laboratory test and numerical analysis. In this study, geogrid was used as a reinforcement of seabed. Three different reinforced areas were selected; one time, three times and five times bottom area of artificial reef. Two-dimensional water channel test was carried out to investigate scour patten of sand and silt grounds. Numerical analysis was also performed to see the velocity vector and scouring patten around artificial reef which was same condition with experiment. The numerical results were in good agreements with the experimental test results. It was found that the geogrid-installed soft ground under artificial reef tends to reduce scour, compared to unreinforced soft ground.

Behavior Characteristics of Composite Reinforced Earth with Improved Soil Surface and Geogrid-reinforced Backfill (지반개량재 전면토체와 지오그리드 보강 배면토체로 형성된 복합보강토의 거동특성)

  • Bhang, In-Hwang;Kim, Tae-Heon;Kim, You-Seong;Kim, Jae-Hong
    • Journal of the Korean GEO-environmental Society
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    • v.17 no.12
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    • pp.27-34
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    • 2016
  • Many steepened slopes have become increasingly advantageous because of the desire to increase land usage and decrease site development costs. The proven concept of tensile reinforcement allows construction of slopes with far steeper face angles than the soils natural angle. Steepened slope face reinforced with improved soil can increase land usage substantially while providing a natural appearance. The paper presents composite reinforced earth with improved soil surface and geogrid-reinforced backfill. For the stability of the steepened slope, the behavior of the composite reinforced earth are validated and verified by case study and numerical analysis. The case study has performed to investigate the deformation of reinforce soil slope for 14 months. Its horizontal behavior by general vertical load shows within the safe range (0.5% of structure height). As a result of numerical analysis and case study, the reinforcement effect of the steepened slope technique using improved soil is sufficient to be constructed as reinforced soil slope.

Reinforcement and Arching Effect of Geogrid-reinforced and Pile-supported Embankments (지오그리드와 말뚝으로 보강된 성토지반의 보강 및 아칭효과 연구)

  • Oh Young-In;Shin Eun-Chul
    • Journal of the Korean Geotechnical Society
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    • v.21 no.10
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    • pp.5-16
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    • 2005
  • Geosynthetic-reinforced and pile-supported embankments have been increasingly used and researched around the world. The inclusion of one or multiple geosynthetic reinforcements over the pile is intended to enhance the efficiency of load transfer from soft ground to piles, to reduce total and differential settlement and increase global or local stability. In this paper, the reinforcement effectiveness and arching effect of the geogrid-reinforced and pile-supported embankments have been studied in terms of field model tests and numerical analysis with varying the space between piles and reinforcement. 2-dimensional numerical analysis has been conducted using the FLAC (Fast Lagrangian Analysis of Continua) program. And load transfer mechanisms between soil-piles-geogrid were investigated. The mechanisms of load transfer can be considered as a combination of embankment soil arching, tension geogrid, and stress concentration due to the stiffness difference between pile and soft ground. Based on the field model test and numerical analysis results, it was found that the geosynthetic reinforcement slightly interferes with soil arching, and helps reduce differential settlement of the soft ground. Also. at the D/b=3 (D: spacing of pile cap, b: diameter of pile), the total settlement is reduced by about $40\%$ compared to that without reinforcement. For $D/b{\ge}6$, the effectiveness of geogrid reinforcement in reducing settlement is negligible.

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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Stability Analysis of Road Embankment Reinforced by Geogrid (지오그리드로 보강된 도로제방 사면의 안정성 해석)

  • Lee, Han-Min;Yoo, Han-Kyu;Suh, Young-Chan;Park, Un-Sang
    • Journal of the Korean GEO-environmental Society
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    • v.2 no.4
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    • pp.39-50
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    • 2001
  • In this study, in order to investigate the effects of reinforcement length and vertical spacing on the factor of safety, the road embankment reinforced by geogrid was analyzed using RSS(Reinforced Slope Stability) program based on limit equilibrium analysis. The result by computer analysis showed that the factor of safety for reinforced slope increased with increasing length of reinforcement and with decreasing vertical spacing of reinforcement up to certain limit. Also, numerical analysis by FLAC was performed on reinforced slope to evaluate the horizontal displacement, horizontal stress, and distribution of tensile forces of reinforcements in the cases of several reinforcement length. The results of analysis showed that the critical failure mode was toe failure or slope failure and the effect by the additional reinforcement length on the slope stability was negligible under stabilized condition.

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