In this study, effort has been made to achieve a comprehensive geophysical investigation on immediate and remote causes of structural/foundation failures, specifically highway(s) within the southwestern basement complex region of Nigeria. Geophysical survey involves the use of Very Low Frequency Electromagnetic method (VLF-EM) which was complemented with electrical resistivity method using two techniques; 2D Electrical Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES) along Akure/Oba-Ile Airport Road, which covers a pilot test of 600 m. The VLF-EM survey produced EM anomalies and identified possible linear features along the study area. The results obtained from the VES were used to determine the second order parameters for determination of subsurface integrity/competence. The geoelectric sections identified three to five geoelectric/geologic subsurface layers along the traverse. The ERT gave information on the subsurface characteristics whose section delineated five major geologic layers comprising of the topsoil, weathered basement, fractured zone, partly fractured basement and the fresh basement. This shows that fracture and weathering are responsible for the structural failures along the study area which are products of probability functions of geodynamics. The methodology can be adopted as a model to proficiently and quickly detect changes in subsurface resistivity, integrity and identify anomalous zones which can serve as useful tool in the understanding of the probability functions of geodynamics that can bring structural and foundation failures within the basement complex region.

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This study investigates the relationship among the various types of rock within the basement complex region and their possible yield in term of groundwater productivity. Four different rock types were considered at various locations in Akure metropolis. Electrical resistivity method was adopted using horizontal profiling utilizing Wenner array as well as Vertical Electrical Sounding (VES) technique using Schlumberger configuration. The horizontal profiling technique was used to determine areas characterized by structural features associated with weak zones that may be diagnostics of cracks, joints, fractures or highly weathered geologic material, while VES was used as a follow up to identified weak zones as a confirmatory test as well as delineation of layer stratification and geologic materials associated with layer parameters that maybe applicable for groundwater occurrence. The results derived from geoelectric parameters were used to determine the second order parameters (Dar-Zarrouk) for groundwater productivity modeling. The finding reflects the various yield capacity of the different rock types that were considered for this study and without prejudice to fracture/thick weathered basement.

This study has evaluated the post-construction subsoil integrity of a distressed building in Ado-Ekiti, Southwestern Nigeria, to decipher the in-situ lithology and structural disposition. Four traverses of 100 m length were established in approximately E-W direction with an inter-station spacing of 10 m. Two Geophysical methods were deployed including the ground magnetic method using Proton Precession Magnetometer and Electrical Resistivity method utilizing 2D Electrical Imaging and Vertical Electrical Sounding (VES) techniques. Twelve (20) VES station points were acquired within the investigated area using Schlumberger configuration which gave relevant information on layer stratification and geoelectric parameters. The obtained results from the VES showed four geo-electric layers comprises topsoil, clayey layer, weathered layer, fractured bedrock, and fresh basement. Low apparent resistivity was delineated from the 2D imaging exhibiting unfit materials at distance between 50 to 75 m and 80 to 100m. The magnetic results showed a series of bedrock ridges and depressions. The integration of results revealed that the majority of the study areas are unsuitable except for central parts which indicate appreciable competence and stability.