Investigation of Bearing Capacity of Soils in Parts of Osogbo, Osun State, Southwestern Nigeria (Published)
When designing foundation for a structure there is 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 soils in parts of Osogbo, Osun state, southwestern Nigeria, with with a view to adding to the existing body of knowledge on bearing capacity of soils in the study area.Disturbed soil samples were collected from twenty different construction sites within the study area. The samples were subjected to the following preliminary and geotechnical tests, using standard procedure: natural moisture content, particle size analysis, specific gravity, Atterberg’s limits, compaction and unconsolidated undrain triaxial. The shear strength parameters, obtained from the triaxial tests, were then inputed into the Terzaghi’s bearing capacity equations to compute the bearing capacity for strip, circular and square footings. Results showed that: 30 % of the soil samples are A-2-4, 25 % are A-2-7 while 45 % are A-2-6 using American Association of State Highway and Transportation Officials (AASHTO); the soils are c-ɸ soils; and square footings had the highest bearing capacity while strip footing had the lowest. The study concluded that the selected soils can be described as fair to good foundation materials.
Keywords: Osogbo, bearing capacity, foundation, shape of footing, soil strength