Index and Mechanical Properties of Collapsible Soils (A Case Study on Ziway-Arsi Negele Highway Project)
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Date
2019-12
Authors
Journal Title
Journal ISSN
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Publisher
Addis Ababa University
Abstract
Collapsible Soils, unlike many other types of problematic soils found in Ethiopia,
did not get the necessary attention in researches conducted to this date. However,
due to their particular engineering characteristics, they exhibit large settlement
upon wetting posing threat to embankments and foundations built over them.
Due to lack of researches on collapsible soils and the limited attention given in
engineering design manuals of the country, many professionals in the construction
industry fails to clearly understand their index and mechanical properties.
This research had the aim of assessing the index and mechanical properties of
collapsible soils found between Zeway and Arsi Negele towns by taking the ModjoHawassa
Dual
Carriageway
Highway
Project,
Lot
3;
Zeway-Arsi
Negele
as
a
case
study.
To this regard, a series of field and laboratory tests were conducted on
representative collapsible soil samples collected from the above-mentioned study
area. Field density test has been conducted to determine the in-situ densities of the
sampling areas. Furthermore, laboratory tests like specific gravity, grading
analysis, Atterberg limits, and moisture-density relationships have been carried out
to determine their index as well as mechanical properties. In so doing, it was
observed that the soils have very low in-situ densities, mainly consist of sands and
silts and low plasticity.
Moreover, in order to investigate the collapse nature of the soil samples, collapse
potential test has been carried out using one dimensional Oedometer by remolding
the samples to their in-situ as well as maximum dry densities so as to perceive the
nature of collapsibility of the soils at their natural state and at their compacted state.
Accordingly, it was found out that the soils have moderate collapse potential at
their natural state and does not exhibit any kind of collapsibility at their compacted
state.
Description
Keywords
Collapsible Soils, Collapse Index, Collapse Potential, Index Properties, Mechanical Properties