• Title, Summary, Keyword: permeability

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Estimation model of coefficient of permeability of soil layer using linear regression analysis (단순회귀분석에 의한 토층지반의 투수계수 산정모델)

  • Lee, Moon-Se;Kim, Kyeong-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.1043-1052
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    • 2009
  • To derive easily the coefficient of permeability from several other soil properties, the estimation model of coefficient of permeability was proposed using linear regression analysis. The coefficient of permeability is one of the major factors to evaluate the soil characteristics. The study area is located in Kangwon-do Pyeongchang-gun Jinbu-Myeon. Soil samples of 45 spots were taken from the study area and various soil tests were carried out in laboratory. After selecting the soil factor influenced by the coefficient of permeability through the correlation analysis, the estimation model of coefficient of permeability was developed using the linear regression analysis between the selected soil factor and the coefficient of permeability from permeability test. Also, the estimation model of coefficient of permeability was compared with the results from permeability test and empirical equation, and the suitability of proposed model was proved. As the result of correlation analysis between various soil factors and the coefficient of permeability using SPSS(statistical package for the social sciences), the largest influence factor of coefficient of permeability were the effective grain size, porosity and dry unit weight. The coefficient of permeability calculated from the proposed model was similar to that resulted from permeability test. Therefore, the proposed model can be used in case of estimating the coefficient of permeability at the same soil condition like study area.

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Permeability Characteristics of Sedimented Clayey Soils (점토퇴적지반의 투수특성 연구)

  • Kim Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.1
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    • pp.72-77
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    • 2005
  • The oedometer test and the constant rate of consolidtion test were performed using the sedimented clayey soil sample. The characteristics of permeability of the clayey soil such as anisotropy, permeability change index, relation with void ratio, and influencing factors, were investigated from the lab. test results. Analyzing the permeability characteristics, the representative permeability coefficient was proposed.

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Air Permeability of Softwoods Imported from the Russian Far East (북양(北洋) 침엽수재(針葉樹材)의 공기(空氣) 투과성(透過性))

  • Jee, Woo-Kuen;Kim, Gyu-Hyeok
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.4
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    • pp.22-31
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    • 1996
  • Air permeabilities for both sapwood and heartwood of the three softwoods(Picea jezoensis, Larix gmelini, Pinus sylvestris), imported from the Russian Far East, in the three different structural directions were measured using steady-state rotameter method. After measuring permeability, the liquid absorption into the longitudinal permeability specimens was measured, and then related with the measured permeability. The longitudinal permeability was overwhelmingly greater than the transverse permeability, with the radial direction showing higher permeability than the tangential direction. There appear to be species differences in permeability of the three softwoods. The mean longitudinal sapwood permeability of P. jezoensis(3.300darcy) and P. sylvestris(3.028darcy) were considerably greater(ca. 25times) than that of L. gmelini(0.134darcy). Also the average longitudinal heartwood permeability of P. jezoensis(0.300darcy) was about 10 times as great as that of P. sylvestris(0.029darcy) and L. gmelini(0.024darcy). The average calculated radius of pit openings in the heartwood was $0.101{\mu}m$ for L. gmelini, $0.152{\mu}m$ for P. sylvestris for and $0.703{\mu}m$ for P. jezoensis. Heartwood permeability increases with the increase in radius of pit pore and the decrease in ring width and in extractive content, even though the correlation between permeability and its affecting factors was dependent on species. However, there was an inverse relationship between specific gravity and permeability, showing poor correlation between them. The correlation between air permeability and liquid retention was fairly high, so it was revealed that prediction of liquid absorption into the wood by using permeability was feasible.

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Experimental study on commingled injection in multilayered low-permeability reservoir

  • Ding, Jingchen
    • Geosystem Engineering
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    • v.20 no.2
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    • pp.71-80
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    • 2017
  • Experiments were carried out using natural cores from low-permeability reservoir on three-layer commingled injection system to investigate the recovery characteristics of commingled injection in multilayered low-permeability reservoir. Results indicate that in the cases of commingled injection, ultimate recovery factor of each single layer was always lower than that of single layer injection. Commingled injection has little influence on the high permeability layer, and the influence is much less under stronger heterogeneity/higher injection rate. However, oil recovery of medium/low permeability layer, especially which of low permeability layer, is greatly influenced by reservoir commingled injection, and the influence is greater under stronger heterogeneity/higher injection. And for commingled injection in multilayered low-permeability reservoir, the ultimate recovery percent of low permeability layer is mainly dependent on reservoir heterogeneity instead of permeability.

Correlation Among Permeability, Apparent Density, And Porosity of Human Lumbar Vertebral Trabecular Bone (인체 요추해면골의 배류계수, 겉보기밀도, 공극비 사이의 상관관계에 관한 연구)

  • 홍정화;강신일
    • Journal of Biomedical Engineering Research
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    • v.18 no.4
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    • pp.333-338
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    • 1997
  • Abnormal intraosseous flow and pressure in trabecular bone could cause various pathological conditions such as osteonecrosis and osteoarthritis. Characteristics of intraosseous fluid flow and pressure generation in porous trabecular bone can be significantly affected by the permeability. Factors which determine the permeability could be the porosity and apparent density of trabecular bone. However, there is little data on the permeability and the relationship among the permeability. porosity, and apparent density of trabecular bone. In this study. the permeability. porosity, and apparent density of human lumbar vertebral trabecular bone were experimentally measured. Also, a power relationship among the permeability, porosity, and apparent density was investigated to understand effects of the porosity and apparent density variations on the permeability of trabecular bone based on Kozeny-Carman equation. A near linear relationship between intraosseous fluid flow and time indicated that the fluid phase flowed through the pores in trabecular bone is governed by the permeability. The permeability of trybecular bone was found to have a significant power relationship with the porosity and apparent density (r: 0.84 and $\textit{p}$< 0.0005). The power relationship could be useful to determine the permeability of trybecular bone after measuring the apparent density and porosity.

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Permeability Influence of Base Soil for Analysis of Road Landfill Stability (도로성토사면의 안정성 분석시 원지반 투수성의 영향)

  • Kim, Young-Muk;Kim, Chung-Ki;Kim, Man-Goo;Kim, Geon-Hae
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.890-897
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    • 2005
  • Stability of embankment is influenced on landfill condition, permeability, shear strength and soil engineering propensity and so on, and need examination in reply because is different according to change of soil property of foundation ground and permeability condition. Analyzed seepage behaviour by finite element method for embankment, and change permeability of base to analyze effect that permeability of ground water table formation before embankment and analyze seepage behaviour to typical embankment in this research. In the case of permeability of foundation ground is 10 more than landfill permeability, rise of groundwater table was changed slightly. Pore water pressure was decreased slowly in landfill after rainfall. The effect of permeability of foundation ground was effected in change of pore water pressure. For permeability of foundation ground is 10 more than landfill, stability of road landfill was small changed during rainfall. But in the case of permeability of base soil similar to landfill permeability, road landfill stability was large decreased during rainfall.

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Effects of Tipping Paper and Plug Wrap on Cigarette Filter Ventilation (팁페이파 및 필터권지 기공도 조합이 제품담배 공기희석율에 미치는 영향)

  • 김정열;김종열;신창호
    • Journal of the Korean Society of Tobacco Science
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    • v.23 no.1
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    • pp.60-64
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    • 2001
  • The variability of a ventilated filter cigarette depends on the details of its construction and one properties of its components and the variations in filter ventilation is effected by many factors such as tobacco column pressure drop, filter pressure drop, tipping paper and plug wrap permeability, and vent position. In this study, the effects of combination of tipping paper and plug wrap on filter ventilation of cigarettes were studied for the target ventilation level under the specific tobacco column and filter tip in order to reduce the variation of filter ventilation. When Nicolas Baskevitch\`s equation on filter ventilation was used to try out Monte Carlo Simulation, at the combination where tipping paper permeability is high and plug wrap permeability is low, even the small change in tipping paper and plug wrap permeability showed high variation of target ventilation level. Also, according to the analysis data of filter ventilation in cigarettes designed at the level of 45% filter ventilation by the combinations with tipping paper and plug wrap, the variation in cigarette filter ventilation was increased as increasing tipping paper permeability and decreasing plug wrap permeability. As the results of this study, the variation of filter ventilation can be reduced by increasing plug wrap permeability/tipping paper permeability ratio in the cigarette design, considering 2-3% of tipping paper permeability variation(%CV) and about 10% of plugwrap permeability variation.

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Permeability imaging in granitic rocks based on surface resistivity profiling

  • Sudo Hiroshi;Tanaka Toshikazu;Kobayashi Tsuyoshi;Kondo Tatsutoshi;Takahashi Toru;Miyamoto Masaharu;Amagai Mitsuru
    • Geophysics and Geophysical Exploration
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    • v.7 no.1
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    • pp.56-61
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    • 2004
  • In order to image the distribution of permeability in granitic rocks, we carried out two-dimensional (2D) resistivity profiling, together with in-situ permeability tests, electrical logging of boreholes, and resistivity measurements of rock core samples in a laboratory. Based on the electrical logging and in-situ permeability data from boreholes, we obtained empirical equations which relate resistivity and permeability of the granitic rocks in the area studied. We then applied the empirical equation to a 2D resistivity section, to produce a 2D permeability section of the granitic rocks. In this paper, we present details of the field data and of the procedure for conversion from the resistivity section to a permeability section. The observed relationship between resistivity and permeability of the rocks is also discussed.

Effect of polyolefin fibers on the permeability of cement-based composites

  • Hsu, Hui-Mi;Lin, Wei-Ting;Cheng, An
    • Computers and Concrete
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    • v.9 no.6
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    • pp.457-467
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    • 2012
  • This study evaluates the permeability of cement-based composites, which are a mix of polyolefin fibers and silica fume. Test results indicate that permeability increases as the water/cementitious ratio increases. Silica fume in cement-based composites produced hydrated calcium silicate and filled the pores. However, permeability decreased as the addition of silica fume increased. Specimens containing polyolefin fibers also provided higher permeability resistance. The polyolefin fiber length did not have a significant effect on permeability. The decrease in the permeability is mainly due to the addition of silica fume and lower water/cementitious ratio. Addition of fibers marginally decreases the permeability. Incorporating polyolefin fiber and silica fume in composites achieved more significant decreases in permeability. The correlated test results reveal the interrelationship between them.

Comparison of Different Permeability Models for Production-induced Compaction in Sandstone Reservoirs

  • To, Thanh;Chang, Chandong
    • The Journal of Engineering Geology
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    • v.29 no.4
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    • pp.367-381
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    • 2019
  • We investigate pore pressure conditions and reservoir compaction associated with oil and gas production using 3 different permeability models, which are all based on one-dimensional radial flow diffusion model, but differ in considering permeability evolution during production. Model 1 assumes the most simplistic constant and invariable permeability regardless of production; Model 2 considers permeability reduction associated with reservoir compaction only due to pore pressure drawdown during production; Model 3 also considers permeability reduction but due to the effects of both pore pressure drawdown and coupled pore pressure-stress process. We first derive a unified stress-permeability relation that can be used for various sandstones. We then apply this equation to calculate pore pressure and permeability changes in the reservoir due to fluid extraction using the three permeability models. All the three models yield pore pressure profiles in the form of pressure funnel with different amounts of drawdown. Model 1, assuming constant permeability, obviously predicts the least amount of drawdown with pore pressure condition highest among the three models investigated. Model 2 estimates the largest amount of drawdown and lowest pore pressure condition. Model 3 shows slightly higher pore pressure condition than Model 2 because stress-pore pressure coupling process reduces the effective stress increase due to pore pressure depletion. We compare field data of production rate with the results of the three models. While models 1 and 2 respectively overestimates and underestimates the production rate, Model 3 estimates the field data fairly well. Our result affirms that coupling process between stress and pore pressure occurs during production, and that it is important to incorporate the coupling process in the permeability modeling, especially for tight reservoir having low permeability.