Air entrapment and consolidation occurring with saturated hydraulic conductivity changes with intermittent wetting

2000 ◽  
Vol 20 (1) ◽  
pp. 9-14 ◽  
Author(s):  
R. M. Seymour
Keyword(s):  
Hydraulic Conductivity ◽  
Saturated Hydraulic Conductivity ◽  
Air Entrapment

An evaluation of air permeability measurements to characterize the saturated hydraulic conductivity of soil reclamation covers

2015 ◽  
Vol 95 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Mingbin Huang ◽  
Heather Rodger ◽  
S. Lee Barbour
Keyword(s):  
Hydraulic Conductivity ◽  
Oil Sands ◽  
Land Reclamation ◽  
Air Permeability ◽  
Saturated Hydraulic Conductivity ◽  
Soil Reclamation ◽  
Air Entrapment ◽  
Soil Covers ◽  
Weathering Processes ◽  
Over Time

Huang, M., Rodger, H. and Barbour, S. L. 2015. An evaluation of air permeability measurements to characterize the saturated hydraulic conductivity of soil reclamation covers. Can. J. Soil Sci. 95: 15–26. The saturated hydraulic conductivity (Ks) of soil covers used in land reclamation is known to change over time as the result of weathering processes. Guelph permeameter (GP) measurements have been used to track the evolution of Ks for soil covers at an oil sands mine near Ft. McMurray, Alberta. Although successful, the method was time consuming and consequently a rapid method of estimating Ks based on in situ air permeability measurements was developed. The objectives of this study were: (1) to use air permeability measurements to characterize the spatial variations of Ks for typical reclamation soils and (2) to compare air permeability measurements to direct measurements obtained through laboratory and GP measurements. The results highlight that the values of Ks estimated from measured air permeability values were higher than the values of Ks measured directly using the GP. This is likely due to swelling of clay soils or air-entrapment during GP measurements. Although the magnitude was over-estimated, the variability of Ks was captured by the air permeability measurements. Consequently, a limited program of comparative GP and air permeameter measurements could be used to more rapidly characterize the Ks of reclamation covers over time.

A COMPARISON OF THREE FIELD METHODS FOR MEASURING SATURATED HYDRAULIC CONDUCTIVITY

1985 ◽  
Vol 65 (3) ◽  
pp. 563-573 ◽  
Author(s):  
D. M. LEE ◽  
D. E. ELRICK ◽  
W. D. REYNOLDS ◽  
B. E. CLOTHIER
Keyword(s):  
Hydraulic Conductivity ◽  
Frequency Distribution ◽  
Sandy Loam ◽  
Measurement Techniques ◽  
Saturated Hydraulic Conductivity ◽  
Air Entrapment ◽  
Field Methods ◽  
Normal Frequency ◽  
Log Normal ◽  
Guelph Permeameter

The saturated hydraulic conductivity, Ks, was measured on a loamy sand, a fine sandy loam, a silt loam and a clay at four 100-m2-area sites in southern Ontario. Twenty measurements of Ks were obtained by each of three different measurement techniques at each of the four sites. The techniques included: (1) the air-entry permeameter method; (2) the constant head well permeameter method using the Guelph Permeameter; and (3) the falling-head permeameter method applied to small soil cores. The Ks data were found to be better described by the log-normal frequency distribution than by the normal frequency distribution. Statistical comparison of the mean Ks values [Formula: see text] indicated significant differences between some or all of the methods within each site. This site-method interaction was interpreted in terms of the influence of macropores and air entrapment on each of the measurement techniques. The measured Ks values ranged over an order of magnitude on the sand, one to two orders of magnitude on the loams, and three orders of magnitude on the clay. The [Formula: see text] estimates averaged over the three methods were: 3 × 10−5 m∙s−1 for the sand; 2 × 10−6 m∙s−1 for the loams and 1 × 10−7 m∙s−1 for the clay. Although all techniques were able to discriminate between the three soil types, the best choice of method for any particular situation appears dependent on the required type and accuracy of the Ks measurement, soil type, and the various practical constraints on the investigation. Key words: Air-entry permeameter, Guelph Permeameter, falling-head permeameter, spatial variability, macropores, entrapped air

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.

Changes over time in near‐saturated hydraulic conductivity of peat soil following reclamation for agriculture

2019 ◽  
Vol 34 (2) ◽  
pp. 237-243
Author(s):  
Jari Hyväluoma ◽  
Mari Räty ◽  
Janne Kaseva ◽  
Riikka Keskinen
Keyword(s):  
Hydraulic Conductivity ◽  
Peat Soil ◽  
Saturated Hydraulic Conductivity ◽  
Changes Over Time ◽  
Over Time

scholarly journals Hydraulic and Swell–Shrink Characteristics of Clay and Recycled Zeolite Mixtures for Liner Construction in Sustainable Waste Landfill

2021 ◽  
Vol 13 (13) ◽  
pp. 7301
Author(s):  
Marcin K. Widomski ◽  
Anna Musz-Pomorska ◽  
Wojciech Franus
Keyword(s):  
Hydraulic Conductivity ◽  
Exchange Capacity ◽  
Saturated Hydraulic Conductivity ◽  
Clay Soils ◽  
Compacted Clay ◽  
Clay Liner ◽  
Compacted Clay Liner ◽  
Drying And Rewetting ◽  
Swelling Characteristics ◽  
Shrinkage And Swelling

This paper presents research considering hydraulic as well as swelling and shrinkage characteristics of potential recycled fine particle materials for compacted clay liner for sustainable landfills. Five locally available clay soils mixed with 10% (by mass) of NaP1 recycled zeolite were tested. The performed analysis was based on determined plasticity, cation exchange capacity, coefficient of saturated hydraulic conductivity after compaction, several shrinkage and swelling characteristics as well as, finally, saturated hydraulic conductivity after three cycles of drying and rewetting of tested specimens and the reference samples. The obtained results showed that addition of zeolite to clay soils allowed reduction in their saturated hydraulic conductivity to meet the required threshold (≤1 × 10−9 m/s) of sealing capabilities for compacted clay liner. On the other hand, an increase in plasticity, swelling, and in several cases in shrinkage, of the clay–zeolite mixture was observed. Finally, none of the tested mixtures was able to sustain its sealing capabilities after three cycles of drying and rewetting. Thus, the studied clayey soils mixed with sustainable recycled zeolite were assessed as promising materials for compacted liner construction. However, the liner should be operated carefully to avoid extensive dissication and cracking.

scholarly journals Characterization of Gas Transport Properties of Compacted Solid Waste Materials

Environments ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 26
Author(s):  
Muhammad Rashid Iqbal ◽  
Hiniduma Liyanage Damith Nandika ◽  
Yugo Isobe ◽  
Ken Kawamoto
Keyword(s):  
Hydraulic Conductivity ◽  
Solid Waste ◽  
Gas Transport ◽  
Bottom Ash ◽  
Gas Diffusion ◽  
Saturated Hydraulic Conductivity ◽  
Dry Density ◽  
Transport Parameters ◽  
Functional Relations ◽  
Mixed Waste

Gas transport parameters such as gas diffusivity (Dp/D0), air permeability (ka), and their dependency on void space (air-filled porosity, ε) in a waste body govern convective air and gas diffusion at solid waste dumpsites and surface emission of various gases generated by microbial processes under aerobic and anaerobic decompositions. In this study, Dp/D0(ε) and ka(ε) were measured on dumping solid waste in Japan such as incinerated bottom ash and unburnable mixed waste as well as a buried waste sample (dumped for 20 years). Sieved samples with variable adjusted moistures were compacted by a standard proctor method and used for a series of laboratory tests for measuring compressibility, saturated hydraulic conductivity, and gas transport parameters. Results showed that incinerated bottom ash and unburnable mixed waste did not give the maximum dry density and optimum moisture content. Measured compressibility and saturated hydraulic conductivity of tested samples varied widely depending on the types of materials. Based on the previously proposed Dp/D0(ε) models, the diffusion-based tortuosity (T) was analyzed and unique power functional relations were found in T(ε) and could contribute to evaluating the gas diffusion process in the waste body compacted at different moisture conditions.

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