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|Title: ||ASSESSEMENT OF ROAD FAILURES CONSTRUCTED ON RED CLAY SOILS OF WESTERN ETHIOPIA AND THEIR REMEDIAL MEASURES|
|Authors: ||HAGOS, GEBRETSADIK|
|Advisors: ||Messele Haile (Ph.D)|
|Copyright: ||2006 |
|Date Added: ||22-Oct-2008 |
|Publisher: ||Addis Ababa University|
|Abstract: ||Some part of the land of Ethiopia is covered with expansive soils and some with nonexpansive.
For this reason, roads could be constructed in areas of expansive or non
expansive soils. Structural failures are observed in roads constructed on expansive soils as
well as in roads constructed on non-expansive soils. Hence, investigation is made to study
the types and causes of road failures constructed on red clay soils of Western Ethiopia.
Visual survey was made on the Addis Ababa- Jimma, Addis Ababa-Goha Tsion and
Addis Ababa-Nekempte roads. From the visual survey, it is found that the route from Addis
Ababa to Nekempte, especially near the town Bako which is located around 251km due west
of Addis Ababa, is severely damaged. Due to this reason, this road is chosen for further
investigation. The investigation covers field tests carried out to determine the insitu
condition of the road materials and laboratory tests on the collected samples in order to
determine the engineering properties of the materials. From the field and laboratory tests, an
attempt was made to examine whether the materials used are at their optimum moisture
content and maximum dry density. Since the performance of road is also greatly influenced
by the engineering property of the underlain soil and the natural environmental conditions,
an attempt was made to determine the adequacy of the underlain material to serve as a
subgrade for road construction.
Another study with the title “Further investigation of road failures constructed on expansive
soils of central Ethiopia, Addis Ababa – Jimma road as a case study” was made by Awoke
Sime in the year 2005. The study investigated causes of failures of roads constructed on
expansive soils of central Ethiopia, where expansive soil is prevalent. Hence, comparison
was made on the types and causes of failures of roads constructed on red clay soils with that
of the roads constructed on expansive soils by comparing with the above work.
From the field tests and laboratory tests carried out, it is observed that the failure of roads
constructed on red clay soils is mainly due to the inadequacy of the base layer for the current
traffic loading and due to the poor construction of the materials used over the subgrade.
Whereas the failure of roads constructed on expansive soils is mainly due to the expansive
nature of the subgrade material|
|Description: ||A Thesis submitted to the School of Graduate Studies of Addis Ababa
University in partial fulfillment of the requirements for the Degree of
MASTERS OF SCIENCE in GEOTECHNICAL ENGINEERING.|
|Appears in:||Thesis - Geotechniques|
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