Application of Geophysical Methods to Building Foundation Studies

Folahan Peter Ibitoye, Felix Vincent Ipinmoroti, Mudasiru Salami, Kunle Joseph Akinluwade, Adeyinka Taofeek Taiwo, Adelana Rasaki Adetunji

1Department of Applied Geophysics, Federal University of Technology, Akure, Nigeria 2Prototype Engineering Development Institute, National Agency for Science and Engineering Infrastructure (NASENI), Ilesa, Nigeria.
1Prototype Engineering Development Institute, National Agency for Science and Engineering Infrastructure (NASENI), Ilesa, Nigeria 2Department of Materials Science and Engineering, African University of Science and Technology (AUST), Abuja, Nigeria.
1Prototype Engineering Development Institute, National Agency for Science and Engineering Infrastructure (NASENI), Ilesa, Nigeria 2Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria.
Prototype Engineering Development Institute, National Agency for Science and Engineering Infrastructure (NASENI), Ilesa, Nigeria.

DOI: 10.4236/ijg.2013.49120                

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.

Keywords

Foundation; Bedrock; Basement; Cracks; Subsurface Instability

Conflicts of Interest

The authors declare no conflicts of interest.

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