Abstract
The study evaluated the structural competency of the subsurface geological materials around Ansarudeen Primary school in Bolorunduro community, Adehun area of Ado Ekiti, Ekiti State, Nigeria to delineate the area that is suitable for building development. The ABEM SAS 1000 was employed for transmitting current and recording the resistivity value of the subsurface layers across the two traverses using the dipole-dipole and the Schlumberger arrays for horizontal profiling and vertical electrical sounding of the survey area respectively. Five VES points were occupied along traverses 1 and 2 with AB/2 of 150m. The field resistivity data were processed using Win RESIST and the Dipro software to generate the geoelectric sections of the survey area. The sounding curves generated were HK, KHA, and A, with HK having the highest number of occurrences. The interpreted result showed that the geoelectric section consist of five layers which are the topsoil, weathered layer, fractured basement layer, partly fractured layer and the fresh basement rock. The resistivity value and subsurface layer thickness for the top soil varied from 115.3 - 752.7 Ωm and 0.3 - 2.1 m respectively. The general overburden thicknesses were estimated at 11m and 23m respectively for traverse 1 and 2. The pseudo section of the horizontal profiling and the geoelectric section of the Vertical electrical sounding revealed similar subsurface lithology along traverse 1 and 2. The result however suggested foundation placement on traverse 1along VES 3 and VES 2 of the geoelectric section or point 16-19 of the horizontal profiling pseudo section.
Geoelectric, horizontal profiling, pseudo section, Schlumberger array, vertical electrical sounding
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