• Title/Summary/Keyword: Geocell system

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Numerical investigation of geocell reinforced slopes behavior by considering geocell geometry effect

  • Ardakani, Alireza;Namaei, Ali
    • Geomechanics and Engineering
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    • v.24 no.6
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    • pp.589-597
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    • 2021
  • The present study evaluates geocell reinforced slope behavior. A three dimensional analysis is carried out to simulate soil and geocell elastoplastic behavior using the finite difference software FLAC3D. In order to investigate the geocell reinforcement effect, the geocell aperture size, thickness, geocell placement condition and soil compaction had been considered as variable parameters. Moreover, a comparison is evaluated between geocell reinforcing system and conventional planar reinforcement. The obtained results showed that the pocket size, thickness and soil compaction have considerable influence on the geocell reinforcement slope performance. Moreover, it was found that the critical sliding surface was bounded by the first geocell reinforcement and the slope stability increases, by increasing the vertical space between geocell layers. In addition, the comparison between geocell and geogrid reinforcement indicates the efficiency of using cellular honeycomb geosynthetic reinforcement.

Effect Reinforced Ground using Geocell (지오셀을 적용한 지반의 보강효과에 관한연구)

  • Shin, Eun-Chul;Kim, Sung-Hwan;Oh, Young-In
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.782-791
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    • 2009
  • This study was carried out the laboratory tests and field plate load test in order to evaluate the reinforcement effect of geocell for road construction. The geocell-reinforced subgrade shows the increment of cohesion and friction angle with comprison of non-reinforced subgrade. In addition, the field plate load test was performed on the geocell-reinforced subgrade to estimate the bearing capacity of soil. The direct shear test was conducted with utilizing a large-scale shear box to evaluate the internal soil friction angle with geocell reinforcement. The number of cells in the geocell system is varied to investigate the effect of soil reinforcement. The theoretical bearing capacity of subgrade soil with and without geocell reinforcement was estimated by using the soil internal friction angle. The field plate load tests were also conducted to estimate the bearing capacity with geocell reinforcement. It is found out that the bearing capacity of geocell-reinforced subgrade gives 2 times higher value than that of unreinforced subgrade soil. In the future, the reinforcement effect of the geocell rigidity and load-balancing effect of the geocells should be evaluated.

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Improvement of pavement foundation response with multi-layers of geocell reinforcement: Cyclic plate load test

  • Khalaj, Omid;Tafreshi, Seyed Naser Moghaddas;Mask, Bohuslav;Dawson, Andrew R.
    • Geomechanics and Engineering
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    • v.9 no.3
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    • pp.373-395
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    • 2015
  • Comprehensive results from cyclic plate loading at a diameter of 300 mm supported by layers of geocell are presented. The plate load tests were performed in a test pit measuring $2000{\times}2000mm$ in plane and 700 mm in depth. To simulate half and full traffic loadings, fifteen loading and unloading cycles were applied to the loading plate with amplitudes of 400 and 800 kPa. The optimum embedded depth of the first layer of geocell beneath the loading plate and the optimum vertical spacing of geocell layers, based on plate settlement, are both approximately 0.2 times loading plate diameter. The results show that installation of the geocell layers in the foundation bed, increase the resilient behavior in addition to reduction of accumulated plastic and total settlement of pavement system. Efficiency of geocell reinforcement was decreased by increasing the number of the geocell layers for all applied stress levels and number of cycles of applied loading. The results of the testing reveal the ability of the multiple layers of geocell reinforcement to 'shakedown' to a fully resilient behavior after a period of plastic settlement except when there is little or no reinforcement and the applied cyclic pressure are large. When shakedown response is observed, then both the accumulated plastic settlement prior to a steady-state response being obtained and the resilient settlements thereafter are reduced. The use of four layers of geocell respectively decreases the total and residual plastic settlements about 53% and 63% and increases the resilient settlement 145% compared with the unreinforced case. The inclusion of the geocell layers also reduces the vertical stress transferred down through the pavement by distributing the load over a wider area. For example, at the end of the load cycle of the applied pressure of 800 kPa, the transferred pressure at the depth of 510 mm is reduced about 21.4%, 43.9%, 56.1% for the reinforced bases with one, two, and three layers of geocell, respectively, compared to the stress in the unreinforced bed.

SOIL STABILIZATION USING GEOCELL (지오셀(GEOCELL)을 이용한 지반 안정)

  • 이진웅;이종덕
    • Proceedings of the Korean Geotechical Society Conference
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    • 1993.10a
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    • pp.33-42
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    • 1993
  • Geocell is a three dimensional cellular confinement system that forms a reocomposite mattress with infill material to increase the bearing capacity dramatically rather than geotextiles of nonwoven and woven fabric type and geogrid. In terms of design, this geocell confinement is quite complex to assess and is different in its hieoretical evaluation and its concept from other geosynthetic products. Thsi study is aimed to help a basic understanding on Geoweb system, which is known to be the most effective and easiest in handling among the geocell systems ever developed, by introducing two method of interpretation for the improvement of bearing capacity. Thus the writers are sillingly to help the geotechnical engineers and the site engineers who might be encountered with the bearing capacity problems on site.

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Reinfocing Effects Using Model Geocell in Sand (모래지반에서 모형 지오셀에 의한 보강 효과)

  • Yoon, Yeo Won;Kim, Poong Sik;Chun, Sung Han
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.3
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    • pp.51-59
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    • 2003
  • Loading tests were carried out for model geocell to study the reinforcing effect by variation of tensile strength, cell height, soil density and embedded depth of geocell. From the result, it could be seen that the ultimate bearing capacity of the geocell system was influenced rather by the connection strength than by the tensile strength of geocell material. Bearing capacity increased with the increase of height to width ratio of geocell for the same relative density, strength and embedded depth. And the bearing capacity ratio(BCR) was higher at low relative density of sand than that of high relative density. The increase of bearing capacity was higher at geocell with high tensile strength than that of low tensile strength. And the influence was clear at higher relative density. Also the BCR was higher at shallow embedded depth of geocell. Without consideration of tensile strength of material, the application of bearing capacity formula suggested by Koerner seems not suitable for the special case with low tensile strength of geocell material.

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Experimental Study for Determination of Horizontal Permeability with considering various Geocell Shapes (지오셀의 형상에 따른 수평투수계수 산정에 관한 실험적 연구)

  • Shin, Eun-Chul;Lee, Woon-Hyun;Kang, Hyoun-Hoi;Oh, Young-In
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.285-292
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    • 2010
  • Recently, it is difficult to find a good soil ground due to the shortage of land for new construction site. Because of this situation, the geosynthetics are commonly used for reinforcing the substructure of the soil ground, and hence improving the bearing capacity and reducing the settlement. The geocell is one of geosynthetics and is the advanced system of geogrid. It is the way to increase earth strength and bearing capacity by using three dimension type of geocomposite. In this paper, the Horizontal permeability was determined with considering various geocell shapes. The permeability test was performed by following method of ASTM D4716(87) and potential filling material for geocell was used. The bearing capacity mechanism which enhances the soil ground with evenly maintaining the degree of the compaction was also analyzed for geocell reinforced ground.

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Numerical analysis of geocell reinforced ballast overlying soft clay subgrade

  • Saride, Sireesh;Pradhan, Sailesh;Sitharam, T.G.;Puppala, Anand J.
    • Geomechanics and Engineering
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    • v.5 no.3
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    • pp.263-281
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    • 2013
  • Geotextiles and geogrids have been in use for several decades in variety of geo-structure applications including foundation of embankments, retaining walls, pavements. Geocells is one such variant in geosynthetic reinforcement of recent years, which provides a three dimensional confinement to the infill material. Although extensive research has been carried on geocell reinforced sand, clay and layered soil subgrades, limited research has been reported on the aggregates/ballast reinforced with geocells. This paper presents the behavior of a railway sleeper subjected to monotonic loading on geocell reinforced aggregates, of size ranging from 20 to 75 mm, overlying soft clay subgrades. Series of tests were conducted in a steel test tank of dimensions $700mm{\times}300mm{\times}700mm$. In addition to the laboratory model tests, numerical simulations were performed using a finite difference code to predict the behavior of geocell reinforced ballast. The results from numerical simulations were compared with the experimental data. The numerical and experimental results manifested the importance that the geocell reinforcement has a significant effect on the ballast behaviour. The results depicted that the stiffness of underlying soft clay subgrade has a significant influence on the behavior of the geocell-aggregate composite material in redistributing the loading system.

A Study on the Bearing Capacity of Shallow Foundation according to the Reinforcement Geocell Layer (지오셀 보강 층수에 따른 얕은 기초의 지지력에 관한 연구)

  • Lee, Kyong-Cheon;Baek, Young-Sik;Park, Young-Hun;Kim, Nag-Young
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.4
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    • pp.85-96
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    • 2003
  • The Geocell system is the advanced system of Geo-grids, and is one of geosynthetics used for earth reinforcement of weak soil. It is the way to increase earth strength and bearing capacity by using three dimension type of geo-composite. This paper analyzed the bearing capacity mechanism of Geocell system for earth reinforcement. Plate loading tests under the model laboratory condition were performed, and the increase of bearing capacity and the decrease of settlement with shallow foundation were evaluated.

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Development on Design Method for Railway Roadbed by Geocell System (지오셀을 이용한 철도노반의 설계기법 개발)

  • Shim, Jae-Bum;Shin, Min-Ho;Cho, Sam-Deok;Chae, Young-Su
    • Journal of the Korean Geosynthetics Society
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    • v.1 no.1
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    • pp.23-29
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    • 2002
  • Since 1980's in U.S.A and Japan, the studies on increasing the bearing capacity of railway roadbed using geocell system have been conducted for repair and reinforcement of railways constructed on soft soils. In this study, the railway roadbed reinforced with geocell system, used for repair and reinforcement of existing railways in Korea, has been analyzed and investigated the results of the previous studies conducted in Korea and other nations. And the method for estimating the railway roadbed thickness was developed based on the equivalent method using the multi-layer theory and the deformation modulus Ev.

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