GEOTECHNICAL PROPERTIES OF SOME LATERITIC SOILS IN OSUN STATE (A CASE STUDY OF IFELODUN AND BORIPE L.G.A)

CHAPTER ONE  
1.0     INTRODUCTION
The 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 road
2.   Ikirun to Iree road
3.   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.    Water
iii.   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 STUDIES
The 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 STUDIES
1.    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.
1.3       SCOPE OF THE PROJECT WORK
The 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 WORK
The 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.