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USGS · 70185534

Hydraulic conductivity of a sandy soil at low water content after compaction by various methods

John R. Nimmo·Katherine C. Akstin
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Abstract

To investigate the degree to which compaction of a sandy soil influences its unsaturated hydraulic conductivity K , samples of Oakley sand (now in the Delhi series; mixed, thermic, Typic Xeropsamments) were packed to various densities and K was measured by the steady-state centrifuge method. The air-dry, machine packing was followed by centrifugal compression with the soil wet to about one-third saturation. Variations in (i) the impact frequency and (ii) the impact force during packing, and (iii) the amount of centrifugal force applied after packing, produced a range of porosity from 0.333 to 0.380. With volumetric water content θ between 0.06 and 0.12, K values were between 7 × 10 −11 and 2 × 10 −8 m/s. Comparisons of K at a single θ value for samples differing in porosity by about 3% showed as much as fivefold variation for samples prepared by different packing procedures, while there generally was negligible variation (within experimental error of 8%) where the porosity difference resulted from a difference in centrifugal force. Analysis involving capillary-theory models suggests that the differences in K can be related to differences in pore-space geometry inferred from water retention curves measured for the various samples.

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John R. Nimmo, Katherine C. Akstin. 1988-03-01. Hydraulic conductivity of a sandy soil at low water content after compaction by various methods. https://doi.org/10.2136/sssaj1988.03615995005200020001x

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