Comparison between various Field and Laboratory Measurements of the Hydraulic Conductivity of three Clay Liners

2009 ◽  
pp. 3-3-22 ◽  
Author(s):  
D Cazaux ◽  
G Didier
Keyword(s):  
Hydraulic Conductivity ◽  
Laboratory Measurements ◽  
Clay Liners

Saturated Hydraulic Conductivity of Clayey Tills and the Role of Fractures

1990 ◽  
Vol 21 (2) ◽  
pp. 119-132 ◽  
Author(s):  
Johnny Fredericia
Keyword(s):  
Hydraulic Conductivity ◽  
American Studies ◽  
Field Measurements ◽  
Present Knowledge ◽  
Saturated Hydraulic Conductivity ◽  
Field Observations ◽  
Laboratory Measurements ◽  
Vertical Hydraulic Conductivity ◽  
Data Field

The background for the present knowledge about hydraulic conductivity of clayey till in Denmark is summarized. The data show a difference of 1-2 orders of magnitude in the vertical hydraulic conductivity between values from laboratory measurements and field measurements. This difference is discussed and based on new data, field observations and comparison with North American studies, it is concluded to be primarily due to fractures in the till.

Effect of incineration ash leachates on the hydraulic conductivity of bentonite-polymer composite geosynthetic clay liners

2022 ◽  
Vol 139 ◽  
pp. 25-38
Author(s):  
Christian Wireko ◽  
Tarek Abichou ◽  
Kuo Tian ◽  
Binte Zainab ◽  
Zhiming Zhang
Keyword(s):  
Hydraulic Conductivity ◽  
Polymer Composite ◽  
Geosynthetic Clay Liners ◽  
Clay Liners

Estimation and Scaling of the Near-Saturated Hydraulic Conductivity

1999 ◽  
Vol 30 (3) ◽  
pp. 177-190 ◽  
Author(s):  
Per Atle Olsen
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Hydraulic Conductivity ◽  
Scaling Analysis ◽  
Laboratory Measurements ◽  
Estimation Errors ◽  
Geometric Means ◽  
Top Soil ◽  
Structured Soils ◽  
Order Of Magnitude

The hydraulic conductivity in structured soils is known to increase drastically when approaching saturation. Tension infiltration allows in situ infiltration of water at predetermined matric potentials, thus allowing exploration of the hydraulic properties near saturation. In this study, the near saturated (ψ≥-0.15 m) hydraulic conductivity was estimated both in the top- and sub-soil of three Norwegian soils. A priory analysis of estimation errors due to measurement uncertainties was conducted. In order to facilitate the comparison between soils and depths, scaling analysis was applied. It was found that the increase in hydraulic conductivity with increasing matric potentials (increasing water content) was steeper in the sub-soil than in the top-soil. The estimated field saturated hydraulic conductivity was compared with laboratory measurements of the saturated hydraulic conductivity. The geometric means of the laboratory measurements was in the same order of magnitude as the field estimates. The variability of the field estimates of the hydraulic conductivity from one of the soils was also assessed. The variability of the field estimates was generally smaller than the laboratory measurements of the saturated hydraulic conductivity.

scholarly journals Effect of Ammonium on the Hydraulic Conductivity of Kaolin and Bentonite as Clay Liners

2020 ◽  
Vol 4 (2) ◽  
pp. 100-111
Author(s):  
Adebola Adebayo Adekunle ◽  
Igba Uvieoghene Tobit ◽  
Ogunrinola Oluwaseyi Gbemiga
Keyword(s):  
Hydraulic Conductivity ◽  
Ground Water ◽  
Tap Water ◽  
Bentonite Clay ◽  
Research Paper ◽  
Low Permeability ◽  
Main Function ◽  
Clay Liners ◽  
Landfill Liners ◽  
Different Sources

: Landfill liners are underlying materials with low permeability whose main function is to mitigate the infiltration of toxic contents into ground water lying beneath. Landfill liners are primarily made of bentonite clay. Bentonite has a very low hydraulic conductivity, that might not be readily accessible, unlike kaolin which is found to have a lower hydraulic conductivity compared to that of bentonite and can be extensively obtained from numerous different sources. Explored, for the purposes of the present research paper, were various ratios of bentonite and kaolin and their hydraulic conductivity, in particular ratios of 90:10 kaolin to bentonite, 80:20 kaolin to bentonite, 70:30 kaolin to bentonite, 60:40 kaolin to bentonite and 50:50 kaolin to bentonite in an effort to achieve an acceptable barrier suitable as a liner / where tap water and ammonium solution were used as permeants. It was concluded that the ratios not lower than 20% bentonite (80:20, 70:30, 60:40 and 50:50) all had their hydraulic conductivity value reduced compared to the 100% kaolin.

Insight into hydraulic conductivity testing of geosynthetic clay liners (GCLs) exhumed after 5 and 7 years in a cover

2017 ◽  
Vol 54 (8) ◽  
pp. 1118-1138 ◽  
Author(s):  
R.K. Rowe ◽  
R.W.I. Brachman ◽  
M.S. Hosney ◽  
W.A. Take ◽  
D.N. Arnepalli
Keyword(s):  
Hydraulic Conductivity ◽  
Unit Area ◽  
Divalent Cations ◽  
Hydraulic Gradient ◽  
Silty Sand ◽  
Geosynthetic Clay Liners ◽  
Clay Liners ◽  
Percentage Area ◽  
Bundle Size ◽  
Insight Into

Four geosynthetic clay liners (GCLs) serving as single liners were exhumed from below 0.7 m of silty sand on a 3:1 (horizontal:vertical) north-facing slope at the QUELTS site in Godfrey, Ontario, after 5 and 7 years. The 300 mm GCL overlaps with 0.4 kg/m supplemental bentonite were all physically intact. The exchangeable bound sodium was completely replaced with divalent cations. The GCL with the smallest needle-punched bundle size (average of 0.7 mm) and percentage area covered by bundles (4%) maintained low hydraulic conductivity (k) when tested under 0.07–1.2 m head with 10 mmol/L CaCl2 solution as the permeant. For GCLs with larger bundles (1.1–1.6 mm) and higher percentage area covered by bundles (9%–14%), k was low when the head was low (0.07 m). Once the applied head increased, k increased by 1–4 orders of magnitude depending on the (i) hydraulic gradient, (ii) size and number of the needle-punched bundles, and (iii) structure and mass of the bentonite per unit area. The results suggest that the GCLs can perform effectively as a single hydraulic barrier in covers providing that the head above the GCL is kept low (e.g., by a suitable drainage layer above the GCL).

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