Introduction: Geophysical characterization refers to the collection of
information associated with subsurface features. Geotechnical involves
engineering structural performance studies which are used to obtain
information on the physical properties of soil and rock around a site to
design earthworks and foundations for proposed structures and for repair
of distress to earthworks and structures caused by subsurface conditions.
Aim: The study was aimed at characterizing the subsurface formations for
the purpose of determining its capacity to withstand engineering
structures.
Materials and Methods: Geophysical techniques involving eight (8)
vertical electrical sounding (VES) and Wenner array were carried out with
two (2) traverses. Geotechnical investigation involving cone penetration
test (CPT) was also carried out.
Results: The results obtained were presented as 1D resistivity profiles
and Pseudo-sections of 2-D. Three (3) geo-electric layers were delineated
within the study area and these comprise of topsoil, peat or clay and silty
sand. The CPT results were used in the calculation of bearing capacity
using Bustamante and Gianeselli equation for pile foundations and
Meyehorf equation to determine the maximum load the materials can
withstand respectively.
Conclusion: The shallow subsurface geology was adjudged to be
mechanically unstable with low penetration resistance values up to the
depth of 11m. The methods conformed and confirmed that shallow
foundation was considered unsuitable for the intended engineering
structure.
Keywords: Meyehorf, Bustamante and Gianeselli, Subsurface, Geology,
Unstable, Foundation.