• Title/Summary/Keyword: Plastic Drain Board

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A Case Study on Test Embankment using Vertical Drain Method at Incheon International Airport (인천국제공항 수직배수공법 시험시공 사례연구)

  • 권오현
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.06a
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    • pp.33-44
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    • 2001
  • The generally known vertical drain methods for improvement of soft ground are Sand Drain, Sand Compaction Pile, Plastic Drain Board, and Pack Drain. Recently, Plastic Drain Board method application in soft ground is widely used. In this case study, it is compared with each other vertical drain methods from the results of monitorning and test embankment. The results of the analysis and the study show that Plastic Drain Board method is relatively acceptable as vertical drain method.

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Characteristics of Biodegradable Plastic Drain Board (생분해성 플라스틱 연직배수재의 특성)

  • Kim, Ju-Hyong;Cho, Sam-Deok;Chai, Jong-Gil;Sato, Hideyuki
    • Journal of the Korean Geosynthetics Society
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    • v.9 no.3
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    • pp.67-75
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    • 2010
  • The tensile strength, permeability and discharge capacity of biodegradable plastic drain boards made with poly lactic acid (PLA) have been tested and verified prior to their usage at field. Based on test results, the tensile strength of biodegradable plastic drain board made with PLA has relatively lower tensile strain and tensile strength than those of plastic drain board. Performance of PLA filter having good permeability and low opening size is proper for the filter of vertical drain board. In case of improving stiffness of PLA filter, biodegradable plastic drain board also satisfies required discharge capacity as use of vertical drain board too.

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Characteristics of the Natural Fiber Drain Board for Environmentally Friendly Soil Improvement Method (자연친화형 연약지반개량공법을 위한 천연섬유배수재의 특성 연구)

  • Kim, Ju Hyong;Cho, Sam-Deok;Jang, Yeon-Su;Kim, Soo Sam
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.9 no.1
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    • pp.1-13
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    • 2006
  • The recent environmental protection issue has diminished the supply of sand for soft ground improvements so much that the prices of sand have shown a sudden rise. Plastic material is one of substitutes for sand material, but plastic is nonperishable and doubtable if it has potential environmental hormone disrupting substances. Moderate-priced natural fiber drain board made with coconut coir and jute filter are in the spotlight recently as an alternative material for sand and plastic drain board etc. Natural fiber drain has not only competitive price but also a characteristic of assimilation into the soils after finishing of its own function. Discharge capacity of the fiber drain board evaluated by triaxial type discharge capacity test was relatively lower than that of plastic drain board. Nevertheless, settlement and pore pressure dissipation behaviors of the fiber drain board and the plastic drain board which were installed in the clayey soil during the composite discharge capacity test were almost similar. It was also found that biodegradation of the fiber drain board was in progress until 18 month after installation in the clayey soil, but they had still enough engineering properties to use at field.

Discharge Capacity of Environmentally Friendly Drains (친환경배수재의 통수능 특성 평가)

  • Cho, Sam-Deok;Kim, Ju-Hyong;Jung, Seung-Yong
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.1
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    • pp.27-36
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    • 2005
  • Discharge capacity of the fiber mat and the fiber drain made with natural fibers abstracted from plant source was evaluated by permeability test for fiber mat and Delft type test and composite discharge capacity test using disturbed clayey soils for fiber drain. The permeability test results for environmentally friendly coconut fiber mat prove that fiber mat has outstanding permeability in substituting permeable sand. However, discharge capacity of fiber drain evaluated by conventional Delft type discharge capacity test was relatively lower than that of plastic drain board. Nevertheless, settlement and pore pressure dissipation behaviors of fiber drain and plastic drain board installed clay soil during the composite discharge capacity test were almost similar to that of plastic drain board. It is found that the natural fiber drain satisfies requiring minimum discharge capacity in substituting the conventional plastic drain board.

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Mechanics of kinking and buckling of plastic board drains

  • Madhav, Madhira R.;Park, Yeong Mog;Miura, Norihiko
    • Structural Engineering and Mechanics
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    • v.3 no.5
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    • pp.429-443
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    • 1995
  • The deformational response of plastic board drains installed to accelerate consolidation of soft soils, is examined as a problem of downdrag. The drain is modelled as a beam-column in which the axial load increases nonlinearly with depth. The soil response is represented by the Winkler medium whose coefficient of subgrade modulus increases linearly with depth. The governing equations for the drain-soil system are derived and solved as an eigenvalue problem. The critical buckling loads and the shape of the drain are obtained as functions of the normalized subgrade modulus of the soil at the top, the parameters signifying the variation of axial load along the length of the drain and the increase of subgrade modulus with depth. The derived deformed shapes of the drain are consistent with the observed ones.

Capacity Evaluation of Cylindrical Plastic Board Drain with The Composite Discharge Capacity Apparatus (복합통수능시험기를 이용한 실린더형 플라스틱 보드 드레인의 성능 평가)

  • Lee, Chan-Woo;Jung, Du-Hwoe;Kim, Yun-Tae;Jin, Kyu-Nam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.293-299
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    • 2008
  • If a conventional type of Plastic Board Drain (PBD) is installed to the deep clay deposit, it is subjected to a high lateral earth pressure. a flow channel of PBD may be reduced by the collapse of cores and clogged by the intrusion of filter into the space between cores which are made by lateral pressure. It could decrease the ability of initial discharge capacity and the reliability of long term discharge capacity. A cylindrical plastic board drain (C-PBD) considered in this study consists of cylindrical core and several supports so that it can prevent the reduction of area of flow channel from the higher lateral earth pressure effectively. The discharge capacity of C-PBD was compared to that of a conventional PBD through performing experiments using the composite discharge capacity apparatus which can consider in-situ condition such as penetration of drains, ground settlement and discharge capacity. As a result, C-PBD showed much better performance than PBD in the ability of discharge. It was observed that the C-PBD was folded whereas the conventional PBD was folded after the experiment.

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Study on Consolidation Behaviors of Soft Ground by Plastic Board Drain Using Model Tests (실내모형실험에 의한 Plastic Board Drain이 적용된 연약지반의 압밀거동에 관한 연구)

  • You, Seung-Kyong;Hong, Won-Pyo;Yoon, Gil-Lim
    • Journal of the Korean GEO-environmental Society
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    • v.4 no.4
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    • pp.17-23
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    • 2003
  • Accurate prediction of consolidation behaviors of the soft ground improved by plastic board drains is not easy because the consolidation characteristics of the improved ground has not been fully elucidated yet. The shape of drains is one of the most important factors which affect the consolidation characteristics of the improved ground. In this paper, a series of model consolidation tests of soft clay ground improved by plastic board drain were carried out, in order to investigate the effect of both plastic board width and stress level on consolidation characteristics of the improved ground. As the results, behaviors of both settlement and excess pore pressure dissipation were elucidated. Also, the non-uniform distribution of water content in the model ground was obtained. Then, in order to investigate the effect of vertical drainage on the consolidation behavior in the model tests, the comparison between experimental consolidation behaviors and Barron's theoretical ones were carried out. As the results, it was elucidated that the consolidation behavior in the model tests was affected not only by radial drainage but also by vertical drainage.

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A Study on the Soft Ground Improvement in Deep Depth by Application of PBD Method Using Model Test (실내모형실험을 통한 PBD공법이 적용된 대심도 연약지반 개량에 관한 연구)

  • Byun, Yoseph;Ahn, Byungje;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.10 no.6
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    • pp.69-77
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    • 2009
  • The shortage of bearing capacity and settlement, shear deformation may occur when constructing a structure such as harbor, airport and bridge on soft ground such as marine clay, silty clay, sandy soil because it is very soft. The various ground improvement methods were applied to obtain preceding settlement of soft ground and strength increase. The vertical drain method has been used to reduce the required time for consolidation of the soft ground. Especially, the PBD (Plastic Board Drain) has been widely used among in the vertical drain method. In this study, a behavior of characteristic was evaluated by operating a compound drainage capacity test about the PBD (Plastic Board Drain) method applied in soft clay in deep depth. As a result, the settlement gradually occurred with increase of surface load. The consolidation settlement was processed with dissipation of pore pressure after surface load of $500kN/m^2$. Accordingly, it was found that change of settlement through load steps was resulted from dissipation of pore pressure. It was also found that the drainage capacity of vertical drains was considerably reduced with pressure increase and time elapse.

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