Thesis Abstract

Abstract
This study focused on investigating the geotechnical properties of lateritic soils in Ifelodun and Boripe Local Government Areas (L.G.A) of Osun State, Nigeria. Lateritic soils are common in tropical regions and are known for their unique engineering behavior. The research involved field surveys, sampling, laboratory tests, and data analysis to understand the specific characteristics of the lateritic soils in the study areas. The field surveys included geological mapping and soil sampling at various locations within Ifelodun and Boripe L.G.A. The samples were collected at different depths to assess the soil profiles and variations. Laboratory tests were conducted on the soil samples to determine their physical and engineering properties, including grain size distribution, Atterberg limits, compaction characteristics, and shear strength parameters. The results of the laboratory tests revealed important geotechnical properties of the lateritic soils in Ifelodun and Boripe L.G.A. The soils were found to have high clay and silt content, with varying degrees of plasticity. The Atterberg limits indicated that the soils were predominantly classified as clayey soils with some exhibiting low to medium plasticity. The grain size distribution showed a significant proportion of fine particles, which influenced the soil's engineering behavior. The compaction characteristics of the lateritic soils were evaluated through standard Proctor and modified Proctor tests. The results indicated that the soils had relatively high maximum dry density and optimum moisture content values, suggesting good compaction potential for construction purposes. The shear strength parameters, including cohesion and internal friction angle, were determined through direct shear tests. The values obtained provided insights into the soils' stability and load-bearing capacity. Overall, the geotechnical properties of the lateritic soils in Ifelodun and Boripe L.G.A were found to exhibit characteristics typical of tropical lateritic soils. The study contributes to the understanding of the engineering behavior of these soils and provides valuable information for construction and infrastructure development in the region. The findings can be utilized in geotechnical design and construction practices to ensure the safe and sustainable development of civil engineering projects in Osun State.

Thesis Overview

1.0 INTRODUCTIONThe study of geotechnical properties of lateritic soil in Osun State is our main focus and objective, the lateritic soil materials that were investigated was taken in six different locations as follows:1. Ikirun to Osogbo road2. Ikirun to Iree road3. Ikirun to Ada road.The investigation helps to describe the sub-surface condition along the three locations and it provide an indication of the availability of materials suitable for pavement structure construction. The geotechnical properties of lateritic soil is important for an highway engineer to enable him to identify and classify the soil, measure its strength, evaluate its drainage properties and help in processing the soil as a highway material. Lateritic soil in the engineering field refers to all unconsolidated material in the earth crust i.e. all materials above bedrock.A soil sample contains:i. Mineral and organic particles.ii. Wateriii. Air The relative amounts of these three phases are indications of the soils properties and conditions. Lateritic soil is found in most area of Nigeria and constitutes the main construction material for roads, bridges, dams and residential and industrial building. The soil testing and quality control of material are designed and performed to ensure adequate quality of constitution as the construction project is being executed. However, this involves laboratory and in-situ testing of materials and preparation and analysis of test results to ensure that works are performed strictly in accordance with the specification requirement. This project work therefore deals with all the laboratory tests which could be used to analyze the lateritic soil geotechnical properties.1.1 AIMS OF STUDIESThe aim of this project work is to determine the geotechnical properties of the lateritic soil used for the construction of road in Osun State.1.2 OBJECTIVES OF STUDIES1. To determine the suitability of the modified soil on civil engineering project.2. To determine some physical properties of the lateritic soil for road construction in any civil engineering project.3. To improve the strength of the soil in case of poor soil quality. LATERITIC SOILS1.3 SCOPE OF THE PROJECT WORKThe scope of the project work formed to Osun State using Boripe and Ifelodun Local Government as a case studies. Two samples were take from each of three different locations namely, Ikirun to Osogbo road, Ikirun to Iree road, Ikirun to Ada road.1.4 LIMITATION OF THE WORKThe following problems were encountered: First problem of transportation from one sample location to the other. Another problem encountered was non-stability of electricity at the soil laboratory where carrying out the test.