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Overconsolidation in Agricultural Soils: I. Compression and Consolidation Behavior of Remolded and Structured Soils
Author(s) -
Veenhof D.W.,
McBride R.A.
Publication year - 1996
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/sssaj1996.03615995006000020006x
Subject(s) - soil water , geotechnical engineering , consolidation (business) , void ratio , degree of saturation , soil structure , soil science , compressive strength , macropore , compaction , saturation (graph theory) , geology , environmental science , materials science , mathematics , composite material , chemistry , combinatorics , accounting , business , mesoporous material , biochemistry , catalysis
The identification of meaningful physical indicators of soil quality is an important part of characterizing the present state of our soil resources. A study was undertaken with the main objective of examining the compressive behavior of remolded (saturated only) and structurally intact (variable degrees of saturation including saturated) solum horizons sampled from an agricultural region in south western Ontario, Canada. The measured compression lines for the majority of soils showed significant convergence as C c , the slope of the virgin compression line (VCL), increased with initial void ratio ( e 0 ) and preconsolidation stress (ρ c ). The deegree of saturation affected C c mostly through its influence on ρ c . Strength gain with progressive desorption was most apparent in nonplastic soils with more than a minimum contnet of structure stabilizing substances (transient strengthening) and in plastic soils with higher e 0 values. The widely adopted compaction paradigm derived from compression of sieved aggregates (i.e., constant C c and VCL displacement to higher void ratios for a given stress with progressive desorption) was found to hold only for soils with relatively uniform e 0 and weaker grades of structure. Samples identified as highly overconsolidated (mostly subsoils) had their measured VCL displaced below the normal compression line (NCL) at ρ c , which occurred when the void ratio difference between the NCL at unit stress and e 0 exceeded ≈0.36. Factors contributing to subsoil overconsolidation were believed to be mostly natural, including secondary compression and soil dessication. A pedotransfer function based on VCL reconstruction and ρ c estimation is proposed for assessing the degree of overconsolidation in agricultural soils located in this part of Ontario.