Geotechnical Evaluation of Lateritic Soil in Baba-Ode Area, Ilorin, North – Central Nigeria

Obaro, R. I. ; Odediran, O. A. ; Iheme, K. O. ; Akakuru, O. C. ; Gbadebo, A. F. (2019)


This study was carried out on lateritic soil at Baba-ode,North-central Nigeria with aim of denoting the geotechnical properties of lateritic soil and its suitability as construction materials. Two disturbed lateritic soil samples (sample A and B) were selected for the various laboratory techniques. The grain size analyses, the specific gravity tests, the atterberg limit tests, compaction, California bearing ratio and shear box tests were carried out on the samples. The grain size analysis shows that sample A is gravelly silt – clayey sand while sample B is silt – clayey gravel composition. Atterberg consistency limit test indicate that sample A has 30.0%, liquid limit 19.5% plastic limit, 10.5% plasticity index, 9.1% shrinkage limit while sample B has liquid limit of 27.0%, 16.2% plastic limit, 10.8% plasticity index and 7.4% shrinkage limit. The soil samples are above the activity (A) line in the zone of intermediate plasticity (CL) which suggests that they are inorganic soils. The samples contain inactive clay indicating little or no swelling tendency and therefore good for construction materials and this would prevent foundation failures. The California Bearing Ratio (CBR) values are 2 – 3% (mean = 2.75%) and 2 - 4% (mean = 2.75%) in sample A and sample B respectively. This implies they are good as subgrade construction materials. The compaction tests for the optimum water content for sample A is 15.0% and 13.0% for standard and modified proctor respectively. The standard and modified proctor for sample B is 15.2% and 14.0% respectively. The compaction tests for Sample A indicate a higher fine fraction and thus a higher optimum moisture content while sample B has higher coarse fraction with lower optimum moisture content. The cohesion falls within 70-90Kpa (mean = 80Kpa) and the internal friction ranges from 250 - 310 with mean of 290. The results obtained from geotechnical analysis suggest that the soil have high bearing capacity, hence, it can be used as construction materials in engineering works. The soil could also support shallow foundation, dam construction, embankments, slope stability and subgrade materials in road constructions.