Investigation on Some of the Engineering Characteristics of Soils in Adama Town, Ethiopia
No Thumbnail Available
Date
2011-12
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
Investigation of the ground conditions is used for the economical design of the sub
structural elements. It is also necessary to obtained sufficient information on type,
characteristics and distributions of a soil and rock underlying at a site of proposed
structures for feasibility and economic studies for the proposed project.
The objective of this research is to investigate the engineering property of soil found in
Adama town. To achieve its objective samples from different parts of the city were
collected and laboratory tests were done on the collected samples.
The grain size analysis test result showed that the dominant proportion of soil particle
in the research area is silt, which have clay content ranging from 5.4 – 40 5%, silt faction
17.6 - 60.7%, sand fraction 14.5 - 54.6% and gravel content from 0.0 – 24.8%.
The result of Atterberg Limit test on the soil in the research area showed a liquid limit
ranging from 29 – 73%, plastic limit ranging from 21 – 35% and plastic index from 13 –
34%.
The Specific Gravity ranges from 2.40 to 2.70. Free swell test conducted on the samples
collected shows range from 18 – 50%.
From the compaction test results the maximum dry density (MDD) of Adama soil
ranges from1.20 to 1.62 g/cm3 and the optimum moisture content ranges 17.5 to 36.5
percent.
According to the Unified Soil Classification System, the soil is categorized as silt and
silty sand. The AASHTO Classification System shows that the usual types of significant
constituent materials of the Adama soil are silt soil and clayey soil.
Finally one-dimensional consolidation test was done and it shows that the area under
investigation is over consolidated in its natural state, have compression index ranging
IX
from 0.33-0.40, recompression index ranging from 0.017-0.066, coefficient of
permeability ranging from 10-7 to 10-9 cm/sec and modulus of compressibility ranging
from 3600-7500 kPa.
Description
Keywords
Civil Engineering