Relationships between Aggregate and Physical and Engineering Properties of Soil

Studies on the aggregate of soil (V)

Abstract

In this paper, quantitative relationships between the aggregate and some physical and engineering properties of soil are researched using the artificial aggregate forming in sandy soil followed by their measurement.
Five varieties of test fields, divided with a Latin square, controlled by the clay content, CaCO₃ content and oil cake content, were prepared for the research. Measurements of the aggregate, dry density, pF-moisture relationships, consistency and soil resistance were carried out from 1983 until 1985.
The following relations were found.
(1) Dry density of soil (Y₁) decreased proportionally to degree of aggregation (X). Relationship between Y₁ and X can be expressed as follows:
Y₁ =-0.0110 X + 1.31 (γ=-0.469***)
(2) Soil moisture corresponding to pF 2 (Y₂) and pF 3 (Y₃) increased proportionally to the degree of aggregation (X). They are expressed as follows:
Y₂ = 0.501 X + 34.2 (γ=0.459***)
Y₃ = 0.537 X + 14.4 (γ=0.606***)
(3) Relationship between the plasticity index (Y₄) and degree of aggregation (X) was proportional and expressed as follows:
Y₄ = 0.613 X + 0.990 (γ = 0.698***)
(4) Engineering properties of soil may be evaluated partially both aggregate and consistency of soil.
Based on the above, it is possible that the relationship between the aggregate and some physical and engineering properties of sandy soil is expressed quantitatively, and that soil structure is classified according to every 10% degree of aggregation.