• Title/Summary/Keyword: High permeability soil

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The Permeability Characteristics of the Reactive Soil - Bentonite Landfill Liner (혼합반응 차수재의 투수특성 연구)

  • 이강원;황의석;안기봉;정하익;김학문
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.545-552
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    • 2002
  • The purpose of this paper is to investigate permeability characteristic of soil-bentonite landfill liner and development of desirable liner system. In this study, permeability tests for soil-bentonite, reactive soil-bentonite and apply bentomat and reactive mat are carried out under the low and high water pressure. According to test result, additional amount of bentonite decreases the coefficient of permeability up to the bentonite mixture ratio of 15%. Therefore, the permeability test for landfill liner's indicated that the use of general water would be in more safe side because the liner system show low permeability duet decrease effect of porous by suspended soild(SS). The permeability of leachate for Zeolite mixture ratio 0, 5, 10% with bentonite mixture ratio 15% showed negligible variation in the permeability with general water. Therefore, Zeolite could be used as a successful that is available purification material for the treatment of leachate, without changing the of landfill liners. Also odious smell could be removed by adding smell amount of Zeolite to the leachate. It was revealed that the bentomat and reactive mat installed in soil-bentonite layer effectively improved the permeability as well as purification of the leachate.

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A study on Permeability of Soil with Different Density (축제용 흙의 밀도변화에 의한 투수계수에 관한 연구)

  • 윤충섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.15 no.1
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    • pp.2904-2912
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    • 1973
  • The density of soil is one of the most important of its engineering properties, and many soil-engineering operations directed toward improving the density characteristics of matecal. This report is a study on relationship between density, permiabilty and other physical properties of compacted soil in various desity grades. The results of the study can be summariged as follow: 1. The optimum moisture content of soil increses with increasing of fine particles and a relationship between both parameter is $w_0=0.1765.n$ Where, n is passing percentage from #200 sieve. 2. The porosity of soil increases with increasing of optimum water content as $e=aw_0+b$ without having relation to compaction ratio. 3. The increment of permeability of soil is high when the compaction ratio is increased and the phenomenon is conspicuous in case of course soil and non-plastic soil. 4. The permeability of soil decreases with increasing of optrimum water content and the phenomenon is conspicuous when compaction ratio decreases. And the permeability is almost constant when optimum water content is more than 25 percent, even though compaction ratio changes. 5. The permeablity of soil increanses when the amount of fine particles is very few, the permeability is almost constant as being impervious condition without having relation to compaction ratio when there in more than 90 percent of fine particles(less than #200 sieve).

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Permeability Coefficient of Unsaturated Soil in Steep Slope Failure Area (붕괴가 발생한 급경사지의 현장 투수계수)

  • Choi, Eun-Kyeong;Kim, Sung-Wook;Park, Dug-Keun;Oh, Jeong-Rim
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.921-926
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    • 2010
  • To examine saturation characteristics of an unsaturated soil in the steep slope area with collapse, it separated dry season from rainy season and measured water content and permeability, and measured permeability by using a tension infiltrometer in the site. In addition, it conducted electrical resistivity survey to look into thickness of ground and geological structure of underground. The collapsed slope increased depth of weathered zone compared to upper slope, and there electrical resistivity anomalous zone caused by the filtrated underground water was observed. The permeability of the collapsed area was observed high compared to upper and lower slopes of retarding basin without collapse, and the permeability measured by dividing the dry season and rainy season was measured high in case of dry season.

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Shear Strength and Permeability Characteristics of Soil Body Reinforced with Linear and Planar Reinforcing Materials (선형보강재와 평면보강재를 적용한 토체의 전단강도 및 투수특성)

  • 차경섭;장병욱;우철웅;박영곤
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.6
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    • pp.162-171
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    • 2003
  • Traditional methods of earth reinforcement consist of introducing strips, fabrics, or grids into an earth mass. Recently, discrete fibers are simply added and mixed with the soil, much the same as cement, lime or other additives. The advantages of randomly distributed fibers is the maintenance of strength isotropy, low decrease in post-peak shear strength and high stability at failure. In this study, new composite reinforcement structures which consist of geotextile and randomly distributed discrete fibers were examined their engineering properties, such as shear strength of the composite reinforced soil and permeability of short fiber reinforced soil. The increments of shear strength of composite reinforced soils were the sum of increments by fiber and woven geotextile, respectively. The permeability of short fiber reinforced soil was increased with fiber mixing ratio.

Experimental study of the effect of microstructure on the permeability of saturated soft clays

  • Chen, Bo;Sun, De'an;Jin, Pan
    • Geomechanics and Engineering
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    • v.18 no.1
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    • pp.49-58
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    • 2019
  • The effect of microstructure on the permeability of two saturated marine clays was studied through a series of falling head permeability tests and mercury intrusion porosimetry (MIP) tests. The key findings from this experimental study include the following results: (1) The permeability of undisturbed specimens is larger than that of reconstituted specimens at the same void ratio due to different soil fabrics, i.e., the pore size distributions (PSDs), even though they have the similar variation law in the permeability versus void ratio. (2) Different permeabilities of undisturbed and reconstituted specimens at the same void ratio are mainly caused by the difference in void ratio of macro-pores based on the MIP test results. (3) A high relevant relation between $C_k$ ($C_k$ is the permeability change index) and $e*_{10}$, can be found by normalizing the measured data both on undisturbed or reconstituted specimens. Hence, the reference void ratio $e*_{10}$, can be used as a reasonable parameter to identify the effect of soil fabric on the permeability of saturated soft clays.

Characteristics of Soil-Water Characteristic Curve and Unsaturated Permeability of Sludge Mixture (정수슬러지 혼합토의 함수특성곡선과 불포화 투수 특성)

  • Lim, Byung-Gwon;Kim, Yun-Tae
    • Journal of the Korean Geotechnical Society
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    • v.29 no.2
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    • pp.57-64
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    • 2013
  • In this paper, in order to solve high water content of water sludge and promote its recycle, sludge mixtures with various mixing ratios were produced. Sludge mixture consisted of water sludge and weathered granite soil. Their physical properties and unsaturated characteristics (soil-water characteristic curve, and unsaturated permeability function) were investigated by laboratory tests. Experimental test results indicated that at a given matric suction volumetric water content of sludge mixture increased as water sludge content increased. Air entry values of sludge mixture increased from 0.9 kPa to 2.4 kPa with an increase in water sludge content or fine content. In addition, unsaturated permeability function, which is an important factor for performing infiltration analysis, was predicted using saturated permeability and soil-water characteristic curve of sludge mixture.

A Study on the Mechanical Compaction of Fill Dam (Fill Dam의 기계 전압효과에 관한 연구)

  • 윤충섭;김주범
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.21 no.3
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    • pp.92-103
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    • 1979
  • The compaction of core zone of the fill dam is very important foe increasing of the Strength of soil mass and reduction of permeability of the core. The principal objects of this study are to give the construction criteria of tamping rollers and to find out the relationships between density and permeability of soil after compaction. The results in this study are summarized as follows. 1. The core zone of fill dam should be compacted more than 8 passed because the compaction effects of clayey soil increase sharply in about 8 passes of roller. 2. The coefficient of permeability (K) increases with the thickness of compaction of soil even though the density is same. 3. The effect of compaction increases with the quantity of coarse materials such as coarse sand and gravel. 4. If D values change from 100 percent to 98 percent and from 100 percent to 95 percent, K values become 2 times and 5 times of initial K value respectively. 5. The coefficient of permeability in the field soil is very high comparing with the result of laboratory test at the same 100 percent compaction ratio, but differences between both results decrease with the decrease of compaction ratio. 6. Thickness of soil layer for the compaction should be increased for heavier compaction machine. 7. In order to get the compaction ratio of 98 percent or more, 10 to 12 passes of roller is generally required with the thickness of soil from 20cm to 30cm.

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Analysis of Soil Mechanical Characteristics according to the Geological Condition in JangHeung Area (지질조건에 따른 장흥지역 토질의 공학적 특성 분석)

  • Song, Young-Suk;Yun, Jung-Mann
    • Journal of the Korean Geosynthetics Society
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    • v.9 no.1
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    • pp.1-11
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    • 2010
  • The soil mechanical characteristics according to geologic conditions were investigated in the study area. The geology of study area was consisted of Ingok Tuff, Yuchi Conglomerate and Dado Tuff. Yuchi Tuff covered about 80% of the study area. The disturbed and undisturbed soils were sampled from the conglomerate area, Tuff area and Shale area, and then a series of the laboratory soil tests was performed. The soils sampled from the conglomerate area have a large dry unit weight and a low permeability relatively, while the soils sampled from tuff and shale areas have a small dry unit weight and a high permeability. It is proven that the soil permeability is highly affected by the effective grain size and the silt and clay content. That is, the soil permeability is increased with increasing the effective grain size, and the soil permeability is decreased with increasing the silt and clay content.

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Changes in the Physiochemical Characteristics of Artificial Soil after Rooftop Planting (옥상녹화 후 인공토양의 이화학적 특성 변화)

  • 안원용;김동엽
    • Journal of the Korean Institute of Landscape Architecture
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    • v.28 no.6
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    • pp.77-83
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    • 2001
  • The purpose of this study is to provide the fundamental material and information for the plant maintenance after rooftop planting through physiochemical characteristics. The characteristics of artificial soils after rooftop planting from 1993 to 1999 was investigated. Fourteen investigation areas were selected from 4 cities(2 areas selected by each year). The analysis of the circumstances of the areas, the physical characteristics, and the chemical characteristics of the soil were conducted. The artificial soil pH ranged 5.26∼7.40 showing that after construction the soil pH tended to decrease. The soil bulk density of the site was lowest in 1999, 0.15g/㎤, and used to increase toward 1993. We found the fact that the soil bulk density increased gradually after rooftop application . The coefficients of permeability of the soils range from 0.016 to 0.052 cm/sec, which seemed to be in good permeability level. The artificial soils had relatively high water moisture capacity of 62.69∼71.36%. The soil organic matter content of the artificial soils ranged from 0.43 to 1.34%. The exchangeable caution concentration in the artificial soil ranged, Na, 2.36∼4.71mg·{TEX}$kg^{-1}${/TEX}, Mg 0.88∼2.84mg·{TEX}$kg^{-1}${/TEX},K 2.97∼9.61 mg·{TEX}$kg^{-1}${/TEX}, and Ca 9.39∼28.23 mg·{TEX}$kg^{-1}${/TEX}. The amount of total N ranged from 0.003 to 0.286% in study sites. Soil chemical properties varied year to year and showed little tend. The research results showed that some characteristics of the artificial soil were changed after rooftop planting, i.e., soil pH and soil bulk density. Soil bulk density had a negative relationship with the coefficient of permeability, showing that the drainage condition might be limited after some period. This study suggests that a diversity of the research in the changes of the plant growth basis on the areas after construction.

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Assessing the impact of nanoclay on the permeability and geotechnical properties of fine-grained soils in landfill liners

  • Mahdi Nikbakht;Fariba Behrooz Sarand;Rouzbeh Dabiri;Masoud Hajialilue Bonab
    • Advances in materials Research
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    • v.13 no.1
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    • pp.19-35
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    • 2024
  • Presented Article evaluates the effect of nanoclay on permeability, compressive strength, and plasticity behavior of fine-grained soil related to the Tabriz landfill site. In this regard, comprehensive experimental study was performed on taken soil samples (42 specimens) with aim of design high-performance liners for Tabriz landfill. The samples was mixed by 0% (control) 3%, 6% and 9% nanoclay and prepared in 1, 7, 14 and 28 days before testing stage. Index tests like particle-size, permeability, atterberg limits, and uniaxial compressive strength (UCS) was conducted on samples. The results show that studied soil is classified as CL in USCS classification and atterberg limits measured as LL is 37, PL is 20.67, and PI is 16.33 which increase into 75, 45, and 30. The assessment presented the LL was increased about 20.27% based on increasing in nanoclay from 0% to 9%. These variations for PL and PI were 21.77% and 18.37%, respectively. Also, the and soil's compressive strength is increase from 120 kPa to 188 kPa and permeability is estimated as 4.25×10-6 m/s which reduced into the 6.34×10-9 m/s with respect the naboclay content increases form 0% to 9%.