Classification And Strength Characteristics Of Soils Along Faculty Of Engineering Road Federal University Oye Ekiti, Ikole Campus

ABSTRACT

This research project aims at classifying and determining the strength characteristics of soils along Faculty of Engineering road, Federal University Oye Ekiti, lkole campus. The road spans about 338m. The relevant soil tests include; particle size analysis, consistency limits (liquid, plastic, and shrinkage limits), natural moisture contents, specific gravity, compaction test, consolidation and shear strength tests. Liquid limit (LL) is defined as the moisture content, in percent, required to close a distance of 12. 7mm along the bottom of the groove after 25 blows. Plastic limit (PL) is the transition from the plastic state to the semisolid state is termed the plastic limit, w. At this state the soil rolled into threads of about 3 mm diameter just crumbles. In this research project, disturbed and undisturbed soil samples is obtained from five labelled TP I, TP 2, TP 3, TP 4, TP 5 at different locations at an interval of 67.6m along the road and taken to laboratory for relevant soil engineering tests carried out includes particle size distribution, natural moisture content, specific gravity test, compaction, consolidation, consistency limit and direct shear test. The reason for spacing sampling is to obtain variation of soil properties. Significant amounts of the particulate constituents of the samples are shown to be fines (percentage passing No. 200 BS sieve). All the samples showed medium to low values of both liquid limit (LL) and plasticity index (Pl). Looking at the sample some having liquid limit (LL) less than 40 and plasticity index (Pl) less than 20. This probably indicates that the soil contains clay minerals of low plasticity. The samples classified as A-7-5 and A- 2-6 (following the AASHTO classification system) and CI and CL (according to USCS classification system). The samples again recorded appreciable linear shrinkage values (8.6-10.7%). The results of the compaction test are values ranges from 14.0-20.9% and 1.53-1.83kg/m3, the specific gravity of the samples ranges within 2.29 to 2.39 respectively. For the shear strength test, the tested samples recorded low values of cohesion (c) ·at TP2 and TP3 and high values of cohesion,(c) at TPI, TP4 & TPS with moderately low values of angle of internal friction (phi) and the bearing capacity of various sampling points ranges from 299.1 kPa to 3406.6kPa.