Geochemical, Index, and Strength Appraisals of Granite-derived Residual Soils

Abstract

This research work examined the geochemical, index, and strength properties of lateritic residual soils from granitic parent rock in Akure, southwestern Nigeria. The aim is to underscore the potential use of such soils as engineering fills materials. The geochemical method involved the use of X-Ray Fluorescence (XRF). The major oxides determined from this analysis were used for the geochemical quantifications of the soils. Analysis of soil index properties involved consistency limits, grain size distribution and specific gravity tests, while the strength analysis involved compaction and unconfined compressive strength (UCS) tests. Results obtained from the index analysis classified the soil profile into behavioral groups VII and VI. These indicates that the soils are of high to intermediate plasticity and compressibility. The UCS values vary from 272.6 to 377.2 kPa while the shear strength values range from 138.8 to 188.6kPa, indicating good bearing capacity. The geochemical results revealed iron-oxide variations as the major influential constituent within the soil profile. Furthermore, the more lateriterizad zones correspond with the more competent horizons. The residual soils from the study area are found to be suitable materials in engineering construction works as Sanitary landfills and Subgrade materials.