TITLE:
Factors Influencing the Soil-Water Characteristics of Unsaturated Tropical Silty Sand
AUTHORS:
B. D. Oluyemi-Ayibiowu, T. O. Akinleye
KEYWORDS:
Soil-Water Characteristics, Soil-Water Characteristics Curve, Tropical Silty Sand Soil, Compaction Water Content, Compactive Efforts
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.7 No.5,
May
30,
2019
ABSTRACT: Fine grain soils have a complex engineering
behaviour which depends but not limited to moisture content, changes in
external pressure and characteristics of the pore medium. Sand often contains a
considerable percent of silt which is expected to alter its natural behaviour.
This composite matrix is referred to as silty-sand. To understand the behaviour
of this matrix under varying moisture conditions, some of the factors
influencing the soil-water characteristics of unsaturated silty sands were
investigated. Representative samples were collected from a river bank after its
index properties were predetermined in the laboratory. The samples were
compacted at different moisture conditions and compactive efforts. With the
pressure plate extractor device, the Soil-Water Characteristic (SWC) was obtained and SWC Curves plotted. Compaction at greater compactive effort
(modified proctor) and optimum moisture content produced the largest air entry
value and reduced air voids. The air entry values of the soils obtained ranged
from 21 kPa to 57 kPa. Also changes in the shape of the SWCC were consistent
with changes in pore size which occur by varying compaction conditions. Result
shows that soil structure, compaction water content, compactive effort and
percentage of fine particles are factors affecting the Soil-Water Characteristics.