TITLE:
Application of Geophysical Methods to Building Foundation Studies
AUTHORS:
Folahan Peter Ibitoye, Felix Vincent Ipinmoroti, Mudasiru Salami, Kunle Joseph Akinluwade, Adeyinka Taofeek Taiwo, Adelana Rasaki Adetunji
KEYWORDS:
Foundation; Bedrock; Basement; Cracks; Subsurface Instability
JOURNAL NAME:
International Journal of Geosciences,
Vol.4 No.9,
November
29,
2013
ABSTRACT: A geophysical survey
involving the electrical resistivity method utilizing the Vertical Electrical
Sounding (VES) and Electrical Imaging Techniques was conducted around
the premises of an area within south-western Nigeria with the aim of studying
structural defects which may be responsible for future problems and
characterizing the soil conditions of the site. A total of 15 VES stations were
occupied using Schlumberger Configuration
with AB/2 varying from 1 to 65 m. In the electrical imaging, dipole-dipole
array was adopted and the two
traverses were occupied in the S-N and E-W directions close to where wall
cracks and subsurface problems were manifested. Five main geoelectric sequences
were delineated within the study area; these include the topsoil (clay and sandy clay), lateritic clay, weathered
bedrock (clay, sandy clay and clayey sand), fractured bedrock and fresh basement. A major
discontinuity (fracture zone) was discovered along the S-N direction, while a
weak zone was also discovered along E-W direction. The result of this research has shown that the
causes of the cracks and distress on the walls within the site may have been
influenced by the differential settlement resulting from the incompetent
subsoil materials and the fractured bedrock on which the foundation of the building was laid.