DEALING WITH SENSITIVE AND VARIABLE SOILS IN NAIROBI CITY
Date
2011Author
Onyancha, CK
Mathu, EM
Mwea, SK
Ngecu, WM
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Nairobi City is mainly underlain by pyroclastic volcanic rocks
that were deposited during the formation of the East
African Rift Valley. Some of the volcanic rocks were deposited in aqueous conditions
over a long period of time and
are
intercalated with
lacustrine
sediments.
River valleys and
other depressions that existed during the periods of
intermittent inactivity were filled with alluvium and clays
. At
building sites
,
the
alluvium
, clays as well a
s
decomposed
volcanic tuffs are found to have variable thicknesses and sensitive to moisture
. The objectives of this
research were: to identify
localitie
s covered by
the
sensitive and variable soils; to determine the geotechnical
properties of the soils an
d to examine the methods and processes that make for a successful construction program.
Geotechnical test results and reports from fifty seven sites underlain by these soils were analysed. The results show
that structures with defects exist side by side wi
th those in sound condition. It is concluded that some methods of
construction work well in these soils. These successful construction methods that are applied to avoid/ remedy total
and differential settlement in buildings are discussed here. Since the methods are quite successful, the authors
suggest use of the same approach
for addressing similar subsoil problems.
URI
http://www.arpapress.com/Volumes/Vol9Issue2/IJRRAS_9_2_12.pdfhttp://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/35696
Citation
IJRRAS 9 (2) ● November 2011Publisher
IJRAS Department of Geology, University of Nairobi