ABSTRACT
The study was to evaluate the index and strength properties of the soil obtained from the Faculty of Basic Medical Sciences construction site, University of Benin, Benin city, Nigeria.The foundation design layout had to be changed during the course of construction of the building due to a detection of a Collapsible soil underneath the structure.
Soil samples were collected from the construction site at three different locations which were selected randomly at a depth of about one metre below the surface. After transported to the Civil Engineering Laboratory, UNIBEN, The specific gravity, natural moisture content, sieve analysis, consistency limits, compaction, California Bearing Ratio (CBR) and the Shear strength tests, were carried out. The Bearing Capacity of the soil was evaluated analytically, where the values obtained were compared with some literature values to infer if the soil sample tested is collapsible.
The tests results that the specific gravity of the soil ranges from 2.48 to 2.65, with an average of 2.58, Moisture Content from 8.01 to 10.65% with an average of 9.28%, OMC of MDD of about 14.74% and 15.43KN/M³, LL of 31.46%, PL of 21.97%, PI 9.50%, shrinkage limit of 4.8%, from the sieve analysis, about 48% of the sample passed through 75 micro sieve, 4.52% fine sand, 41.27% medium sized sand and 4.13% coarse sand, an average soaked CBR of 2.4% and unsoaked CBR of 2.56%, cohesion of about 16.79kN/m² and an angle of internal friction of 6.533°. The average Bearing Capacity was evaluated to be abput 190.9kN/m². When these results were compared with literature values, it can be concluded that the soil is collapsible.
