GEOELECTRICAL INVESTIGATION OF SUBSURFACE STRUCTURES AND SOIL CORROSIVITY AT UNIONS SITE, GIDAN KWANO FEDERAL UNIVERSITY OF TECHNOLOGY MINNA NIGERIA

Abstract

Vertical electrical sounding (VES) was carried out at union site Gidan Kwano Campus, Federal University of Technology Minna, Nigeria. The objective is to delineate area suitable for structural development and soil corrosivity of the study area. Schlumberger electrode configuration was adopted with maximum current electrode spacing (AB/2) of 100m. The profile separations was 100 m with inter grid spacing of 100 m. Total number of sixty (60) vertical electrical sounding (VES) stations were covered. The interpretaion was done using IP2 WIN software and it revealed three distinct geologic layers. These include topsoil with resistivity values range between 11.41 and 1009 ohm-m and thickness is relatively thin and ranges from 11 to 963 ohm-m with thickness ranges from 1 m to 45 m which indicate high degree of weathered/ fracture and or/ water saturation. The fresh basement has resistivity values that range between 12 and 2983 ohm-m. All the soundings were 3 -layered and are characterised by A, H and Q curve types. Seventeen (17) VES. station were delineated for high rise building having depths to fresh basement varying between 2 m to 5 m(where consolidated basement is shallow with high resistivity value). The corrosivity and 79% suggest practically non corrosive. The result reasonably provide information areas where high rise building can be sited and iron pipe can be laid in order to safeguard the hydrological setting of the area.