GEOELECTRICAL INVESTIGATION OF THE EARTH SUBSURFACE FOR PRE-FOUNDATION STUDIES AT AIRPORT HOUSING ESTATE, MAIKUNKELE, MINNA, NIGER STATE, NIGERIA

Abstract

Geoelectrical investigation was carried out using Geosensor Terrameter DDR1 at Airport Housing Estate, North Central Nigeria, Minna. The study area is bounded by latitude 090.39′ N to 090.40′N and longitude060.26′ E to 060.27′Eandlies within the basement complex region of Northern Nigeria. Vertical Electrical Sounding and Electrical Resistivity Profiling techniques were carried out for the survey. The aim of the survey was to determine the subsurface layer parameters (resistivity, depth and thickness) which shall be employed in delineating sites for building construction. A total of ten profiles with twenty stations along each profile at intervals of 50 m were investigated. The ERP results were used to produce an apparent resistivity contour map from which the high resistivity points were obtained and subjectedto Vertical Electrical Soundings. The VES has a maximum current electrode separation (AB/2) of 100 m. The results obtained from VES plots reveal three distinct geoelectric layers; the top soil, the weathered/fractured layer, the fractured/fresh basement layer. Three distinct curve types were observed for the entire VES plotted curves; H-type, A-type and K-type. The areas suitable for building construction and Civil Engineering works are; The South, East and extremes of North-Western and North-Eastern parts of the study area. The points identified as great threat for high rising buildings and Civil Engineering works are E18, A18, G14, D13, G17 and F9 due to presence of clay content and weathered basement at shallow depth ranging between 0.8m to 5.01m.