Abstract:
Proper understanding of Engineering properties of soils is utmost important in any location where
all structures are to be founded. The study area of this research is located at Sokoru town, North
east of Jimma as part of Jimma Zone. The objective of this study is to investigate some of the
engineering properties of soils found in Sokoru town in order to understand clearly the nature of the
soil and also to give information for the design, construction and environmental assessment, so that
suitable foundation can be recommended for better design and construction in the town. From
reconnaissance survey, it has been observed that the Town is covered by red clay soil.
Representative disturbed and undisturbed samples from ten test pits were collected from different
parts of the town.Laboratory tests were carried out including specific gravity, natural moisture
content, Atterberg limits, unconfined compressive strength, consolidation, free swell, Gradation
analysis and permeability tests. Based on the results of this study, the grain size distribution
indicates all soil samples have more than 50% clay material. Therefore,clay type of soil is
dominantly located in the study area. The specific gravity of the soil ranges from 2.5 to 2.73. While
the Atterberg limit tests results, the soil is highly plastic clay, and the degrees of activity of most of
the study area soils are inactive with maximum Activity index of 1.19. The soil has free swell
between 8 % and 49% which also indicaes the soil is not expansive soi. The consistency of soils
which are stiff to hard as identified based on the liquidity index value. The compaction test result
shows that maximum dry density (MDD) ranges from 1.22 g/cm3
to 1.39 g/cm3
and the optimum
moisture content (OMC) ranges from 27% to 37%. In addition, the unconfined compressive strength
of the soils in the study area ranges from 154.12kN/m2
-354.21kN/m2
and undrained shear strength
range from 77.1kN/m2
–177.12kN/m2
. Likewise, consistencies of the soils ranges from stiff to very
stiff. One-dimensional consolidation tests were done, of which the result showed that the soils have
compression index rangs from 0.23-0.39, swelling index ranges from 0.19-0.02. The coefficient of
permeability (4.58*10-4
to 3.11*10-5
cm/sec) indicating that the soil investigated is impermeable
