Application of Geophysics in Pre Foundation Studies

ABSTRACT

Frequency of structural failure globally has necessitated geophysical investigation of subsurface geology of a site for engineering construction works. Electrical resistivity method was used on a proposed lecture hall site at Federal University Oye Ekiti Institute of part time studies, Aiyegbaju Ekiti, Ekiti State, Nigeria. The purpose of the study is to provide detailed information on the subsurface for documentation and reference for durable and sustainable construction work. Electrical resistivity imaging technique using dipole – dipole electrode array on three traverses were established from which geophysical data were acquired with ABEM SAS 4000 resistvity meter. These points serves as six (6) sounding zone further investigated using Schlumberger electrode array with vertical electrical sounding technique. The acquired data were proccessed and inverted using WINRESIST. The 2D inverted model revealed some incompetent zones responsible for structural instability from the comprehensive interpretation it is deduced that the building can fail, if it is constructed within incompetent clay materials and lateral inhomogeneity. The choice of foundation materials, clay content and topography elevation should be put into consideration.Deep foundations in form of piles were encouraged to avoid structural failure.