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Hydraulic Conductivity of a Sandy Soil at Low Water Content After Compaction by Various Methods
Author(s) -
Nimmo John R.,
Akstin Katherine C.
Publication year - 1988
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1988.03615995005200020001x
Subject(s) - compaction , hydraulic conductivity , porosity , centrifuge , bulk density , soil science , water content , saturation (graph theory) , capillary action , soil water , degree of saturation , soil compaction , water retention , centrifugal force , materials science , geotechnical engineering , mineralogy , chemistry , composite material , environmental science , geology , mathematics , geometry , flow (mathematics) , physics , combinatorics , nuclear physics
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.