Assessment of Bearing Capacity of Soils in Ile-Ife

Abstract:

In foundation design, there is the need to determine the bearing capacity of the underlying soil on which the foundations will be laid. This study therefore investigated the bearing capacity of selected soils in Ile-Ife, Osun State, Southwestern Nigeria. This was with a view to assessing the suitability of the soils as foundation materials. Twenty soil samples were collected from identified twenty construction sites within the study area. Preliminary and engineering properties tests such as natural moisture content, particle size analysis, specific gravity, Atterberg limits, compaction and triaxial were conducted on the soil samples. Shear strength parameters were determined from the results of the triaxial test, and the parameters were subsequently imputed into the Terzaghi’s bearing capacity equations to obtain the bearing capacity of the soils. Results showed that, 80 % of the soil samples fell into A-2-7, using American Association of State Highway and Transportation Officials (AASHTO) classification. Using Unified Soil Classification System (USCS), 70 % of the soil samples were well-graded sand (SW). For strip footings, the bearing capacity values ranged from 83.15 kN/m2 to 2697.08 kN/m2; for circular footings, the values ranged from 105.14 kN/m2 to 2791.83 kN/m2; and for square footings, the values ranged from 105.20 kN/m2 to 2932.06 kN/m2. It was concluded that all the samples were c-ϕ soils, and they could be described as excellent to good foundation materials.