ABSTRACT
This study was to evaluate the index and compressibility properties of the soil obtained from the Faculty of Basic Medical Sciences construction site, University of Benin, Benin city, Nigeria.These parameters are part of the most important soil parameters, necessary to be known before each building project.
Soil samples were collected from the construction site at three different locations which were selected randomly at a depth of about 1.0m below the earth surface. After transported to the Civil Engineering Laboratory, UNIBEN, the specific gravity, natural moisture content, sieve analysis, Atterberg limits and consolidation test were carried out.All the laboratory tests on the soil were evaluated analytically, where the values obtained were compared with some literature values.
From the tests results, the specific gravity of the soil had an average of 2.58;average Moisture Content of 9.28%; Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) were 14.74% and 15.43kN/m³ respectively; Liquid Limit (LL) of 31.46%, Plastic Limit (PL) of 21.97%, Plasticity Index (PI)of 9.50%; 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. These studies were motivated by the fact that in this region, compressibility properties of soil have huge effects on buildings. However, the average compressibility results showed that the magnitude of settlement at the investigated area was 21.49mm, the time required for the specified settlement to occur was 239.52 m2/ year and the amount of the soil deformation experienced at the given area per load was 3.37 x 10-6m2/kN. The British standard, BS 1377-2:1990 specified that consolidation settlement less than 25mm is safe for foundation laid on sandy clay soil. Hence the compressibility of soil at the investigated area was safely good.
