• Title/Summary/Keyword: vertical drainage

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EXACT SOLUTION FOR STEADY PAINT FILM FLOW OF A PSEUDO PLASTIC FLUID DOWN A VERTICAL WALL BY GRAVITY

  • Alam, M.K.;Rahim, M.T.;Islam, S.;Siddiqui, A.M.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.16 no.3
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    • pp.181-192
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    • 2012
  • Here in this paper, the steady paint film flow on a vertical wall of a non-Newtonian pseudo plastic fluid for drainage problem has been investigated. The exact solution of the nonlinear problem is obtained for the velocity profile. Also the average velocity, volume flux, shear stress on the wall, force to hold the wall in position and normal stress difference have been derived. We retrieve Newtonian case, when material constant ${\mu}_1$ and relaxation time ${\lambda}_1$ equal zero. The results for co-rotational Maxwell fluid is also obtained by taking material constant ${\mu}_1$ = 0. The effect of the zero shear viscosity ${\eta}_0$, the material constant ${\mu}_1$, the relaxation time ${\lambda}_1$ and gravitational force on the velocity profile for drainage problem are discussed and plotted.

Experimental Study on Consolidation Behavior of the Smeared Soil for Various Spacing Ratios of Vertical Drains (다양한 배수재 간격비에 따른 스미어 발생 지반의 압밀거동에 대한 실험적 연구)

  • Yune, Chan-Young;Kang, Hee-Woong;Jung, Young-Hoon
    • Journal of the Korean Geotechnical Society
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    • v.27 no.4
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    • pp.77-87
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    • 2011
  • To investigate the effect of drainage spacing and smear on the rate of consolidation and the efficiency of vertical drain method, a series of consolidation tests with a large consolidation chamber and special equipment for inserting mandrels were conducted. As the smeared region increases, total settlement in over-consolidated clay increases whereas apparent change in settlement does not appear in normally consolidated clay. Vertical drain generally accelerates the rate of consolidation, while it could also deteriorate the efficiency of vertical drain method even for the decreasing drainage length and spacing ratio.

Finite Element Analysis based on the Macroelement Method for the Design of Vacuum Consolidation (진공압밀공법 설계를 위한 Macro-element법 기반 유한요소해석)

  • Kim, Hayoung;Kim, Kyu-Sun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.8
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    • pp.29-37
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    • 2022
  • A three-dimensional analysis is required to interpret the drainage behavior of an improved ground with vertical drains, and the macroelement method enables efficient interpretation considering the three-dimensional drainage effect of vertical drains under two-dimensional plane strain condition. In this study, a novel finite element analysis program was developed by applying the macroelement method to the vacuum consolidation method used in ground improvement practice. The conventional macroelement method was used to calculate the amount of drainage from the vertical drain by setting the excess porewater pressure in the drainage material to zero; however, the program developed in this study was improved to consider negative excess porewater pressure as an actual vacuum consolidation condition. To verify the performance of the program, because of a comparison with the measurement values at the site where the vacuum consolidation method was applied, results predicted by the program and field measurement data showed similar settlement behavior.

The Proposal of a New Drainage System without Incline of Piping and Experiment on Drainage Flow Characteristics (구배가 없는 신배수시스템의 제안 및 배수유동 특성에 관한 실험적 연구)

  • Cha Young-Ho;Yee Jurng-Jae
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.5
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    • pp.452-458
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    • 2005
  • In Korea, pumping pipe using gravity way by water is most popular method in drainage system. But, it is difficult to repair a drainpipe in this method because the drain pipe diameter is increased as using this method. In this research, we propose a new drainage system. The system aim for an adaptedness with buildings, freedom of plan, construction and renewal in water pipe equipments, etc. The new system is not need of incline of piping, and it uses drainage power that is changed potential energy by high velocity flow as making Siphonage at vertical pipe. Therefore, the diameter of piping can decreased than existing piping system established in the ceiling. Also because connecting position will be located at the lower part, it is changed the potential energy of drainage to the high velocity flow. In addition, drainage will be smooth because the fixture drain is linked by each drain pipes.

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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Comparative Study on the Subsurface Drainage Discharge Performance by the Type of Non-Excavation Subsurface Drainage Culvert (비굴착 지하배수암거 형태별 지하배수 성능 비교분석)

  • Kim, Hyuntai;Ryu, Jeonyong;Jung, Kiyuol;Seo, Donguk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.6
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    • pp.73-81
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    • 2018
  • In this study, subsurface discharge performance has been studied through theoretical seepage analysis on four types of culverts that can be installed under the condition of non-excavation, such as (a)perforated pipe(${\Phi}50mm$), (b)perforated pipe+horizontal mat (B50cm) (c)perforated pipe+horizontal mat+vertical gravel(B<10cm), (d)perforated pipe+vertical gravel(B<10cm), and existing typical type (e)perforated pipe with gravel (B40, h=40cm) which can be installed by excavation. The analysis results were as follows. i) Subsurface discharge performance per unit (m) was (a)type 56%, (b) 91%, (c) 96%, (d) 76%, respectively, lower than the value of (e)culvert. ii) However, considering that non-excavation culvert can be installed at a spacing of 5m with the installation cost of the existing excavation culvert at the interval of 10m, it was analyzed that unit subsurface discharge(q) of (a)20.2mm/day(110%), (b)32.8(178%), (c)34.6(188%) (d)27.5(149%) in the four types of non-excavation culvert installed at intervals of 5m under the condition of $ k=10^{-4}cm/s$ was much larger than the amount of (e)type 18.5(100%), existing excavation culvert installed at 10m interval. iii) Through the test construction, peak subsurface drainage discharge($q_p$) was 38.4mm/day, which is larger than the value of design criteria and confirmed that it satisfies the analysis results as well. iv) In particular, it was evaluated that (b)perforated pipe+horizontal mat(B50cm) are low cost, high efficiency subsurface drainage culvert type with sufficient drainage performance(178%).

Anisotropy in Coefficient of Consolidation of Clay (점토의 압밀계수에 대한 이방성)

  • 강병희;이윤규;김경태
    • Journal of the Korean Geotechnical Society
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    • v.15 no.1
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    • pp.141-149
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    • 1999
  • In order to investigate the anisotropy in the coefficient of consolidation of the clay deposit, a series of consolidation tests were carried out on the artificially deposited clay sample by both Rowe-type and conventional consolidometers. The results of the tests showed that the coefficient of consolidation for radially inward drainage by Rowe-type consolidometer was about two times larger than that for vertical drainage by the conventional consolidometer. The smear effect caused by vertical sand drain installation was found to be significant, especially in the overconsolidated region, but smaller with the increase in consolidation pressure.

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Assessment of Drainage Properties of PBDs(Prefabricated Board Drains) for Soft Soil Reinforcement

  • Jeon, Han-Yong;Kim, Hong-Gwan;Chang, Yong-Chai;Chung, Chin-Gyo
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.105-105
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    • 2003
  • Theoretical studies have been performed for drainage and filtration characteristics, low consolidation rate of sandmat and prefabricated horizontal and vertical drain. Discussion on quality control and methodology, cost analysis for sandmat and prefabricated horizontal drains were performed.

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A Surgical Experience of Adult TOF with Anomalous Systemic Venous Return (체정맥 이상환류를 동반한 성인 활로씨 4증후군의 치험 1례)

  • 유환국
    • Journal of Chest Surgery
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    • v.24 no.11
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    • pp.1154-1159
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    • 1991
  • Anomalous systemic venous return to the right atrium is clinically innocuous and cause no functional disturbances or physiologic abnormalities by themselves and consequently require no treatment but may be surgical importance. We experienced a case of adult TOF combined with anomalous systemic venous drainage. Rudimentary right SVC with draining left sided vertical vein and IVC with separately drained left vein was revealed at operation time. With the bicaval cannulation, large sucker was used for drainage of blood from the left hepatic vein. Postoperative angiocardiogram showed above findings and combined double inferior vena cava at lumbar level.

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Numerical Modelling of Vertical Drains Installed in Soft Deposit under Embankment (성토재 아래의 연약지반에 설치된 연직배수재의 수치모델링)

  • 이승래;김윤태
    • Geotechnical Engineering
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    • v.12 no.6
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    • pp.127-138
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    • 1996
  • The in-situ consolidation behavior of drainage system-installed deposits has three dimensional characteristics. Therefore, for an approximate 2-D plane strain consolidation analysis, it is necessary to convert the 3-D spatial flow of actual cases into the laminar flow simulated by the 2-D plane strain model. . In this paper, in order to properly model the effect of three dimensional characteristics, an equivalent and efficient model has been applied in a finite element technique for the analysis of the drainage system-installed soil deposits. The equivalent two dimensional model involves equivalent permeabilities and drainage widths. To validate the equivalent two dimensional model, three dimensional analyses were per formed by using the ABAQUS program and the results of 3-D analyses were compared with those of the 2-D analyses. By using the proposed equivalent model, one may be able to appropriately predict the consolidation behavior of drainage system-installed soft deposits.

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