ABSTRACT

Geophysical investigations involving the use of 2D and 3D electrical resistivity imaging techniques have been carried out at the proposed site of the KNUST Teaching Hospital Building in Kumasi, Ghana, to study the nature of the subsurface structure to assess its suitability for the construction of superstructures. Part of the site was an old refuse dump. The main objectives are to determine the depth to the bedrock, and the possible presence of faults, fractures, voids and clay that may pose a danger to the structures that are to be constructed. Twenty eight (28) high-resolution 2D electrical resistivity images were acquired using the Wenner configuration with both electrode and profile separations of 4 m. The roll-along technique was employed to cover the profile length of 200 m which was constant for all the lines. The 2D resistivity data were collated and inverted to produce a 3D image. The 2D and 3D models allowed the location of clay soil, fractures, bedrock and seepage paths from the refuse dump that used to be there. The results showed that the site is suitable for the construction of the proposed KNUST Teaching Hospital.