Application of Geophysical and Geotechnical Methods to Site Characterization for Construction Purposes at Ikoyi, Lagos, Nigeria
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Date
2011
Authors
Oyedele, K.F
Oladele, S
Adedoyin, O
Journal Title
Journal ISSN
Volume Title
Publisher
Journal of Earth Sciences and Geotechnical Engineering
Abstract
Abstract
An integrated geophysical and geotechnical survey was carried out in a proposed
engineering site at Ikoyi, Lagos, Nigeria. The survey aimed to image shallow
subsurface with a view to evaluate the stratigraphy and competency of the shallow
formation as foundation materials. Geotechnical investigation involving Cone
Penetration Testing (CPT) and Standard Penetration Testing (SPT) were carried
out on the site. Geophysical technique involving Vertical Electrical Sounding
(VES) was also implemented and the data were processed, inverted and
interpreted. Geophysical and geotechnical tests showed good agreement. Four to
five subsurface layers were delineated within the study area: the topsoil loose sand,
peat/clay, sandy clay, sand and clay. This indicates good correlation with the soil
layers in bore logs. The existence of loose sand, peat and clay near at the surface is
capable of being inimical to building structures. The subsurface layers up to the
depth of 16 m are mechanically unstable with low penetration resistance value
which may not serve as good foundation materials. Shallow foundation is
considered unsuitable for the intended building. In view of unsuitability of shallow
foundation in this area, structures in this area should be safely founded in
competent and mechanically stable coarse sand through pilling.
Description
Keywords
Geophysics , SPT , VES , Resistivity , foundations
Citation
Oyedele, K. F., Oladele, S., & Adedoyin, O. (2011). Application of geophysical and geotechnical methods to site characterization for construction purposes at Ikoyi, Lagos, Nigeria. Journal of Earth Sciences and Geotechnical Engineering, 1(1), 87-100.