Project Abstract

Soil compressibility is a crucial factor in geotechnical engineering as it directly influences the behavior of soil under different loading conditions. Understanding the compressibility properties of soil is essential for various construction projects, including building foundations, embankments, and retaining structures. This research project aims to investigate the compressibility properties of soil through laboratory testing and analysis. The study will involve conducting a series of oedometer tests on soil samples collected from different locations to determine their compressibility characteristics. The oedometer test, also known as the consolidation test, is a standard method used to measure the compression and settlement behavior of soil under a constant vertical load. By subjecting the soil samples to incremental vertical loads and measuring the corresponding settlements over time, the compressibility parameters such as the compression index and the coefficient of consolidation can be determined. In addition to the oedometer tests, the research will also explore the influence of various factors on soil compressibility, such as soil type, moisture content, organic content, and initial void ratio. Different soil types exhibit varying compressibility properties due to differences in particle size distribution, mineral composition, and fabric structure. Moisture content plays a significant role in soil compressibility as it affects the soil structure and pore water pressure. Organic content can also impact soil compressibility by altering the soil fabric and reducing the soil's ability to withstand external loads. Furthermore, the initial void ratio of the soil, which is the ratio of void volume to solid volume at the beginning of the test, can significantly affect the compressibility behavior of soil. Soils with higher initial void ratios tend to compress more under applied loads compared to soils with lower initial void ratios. By investigating the combined effects of these factors on soil compressibility, this research aims to provide valuable insights into the behavior of different types of soil under varying loading conditions. The findings of this study will contribute to the existing knowledge on soil compressibility and help engineers and geotechnical professionals make informed decisions in designing and constructing various civil engineering projects. By understanding the compressibility properties of soil, it is possible to predict the settlement of structures more accurately, assess the stability of slopes and embankments, and optimize foundation designs to ensure the long-term performance and safety of infrastructure projects.

Project Overview

INTRODUCTION

Maryland is located in Enugu South in Enugu State. The subsoil of this region consists of fine grained soils with a considerable part of soft soil deposit which extends to a considerable depth.

      When a compressive load is applied to a soil mass, the volume of the soil mass tends to reduce, due to reduction in its voids. This reduction in volume of a soil mass on application of a compressive stress can rather be placed either normally (laterally), or vertically or in both directions depending on how the soil mass is allowed to deform. When a vertical compression deformation is non-uniform it poses serious danger to the safety of structures and other civil engineering facilities, therefore there is need to study the compressibility properties of soil in Maryland.

1.1.1 COMPRESSIBILITY

      This is the degree to which a soil mass decreases in volume when supporting a load.  Compressibility is reduced in a situation where there are more coarse-grained soils in contact with each other. It increases as the proportion of small particles increases and becomes highest in fine-grained soils which contain organic matter.

      Compressibility is approximately proportional to the plastic index. The greater the plastic index (PI), the greater the compressibility of the soil. (Adeyemi 2014).

1.1.2     PLASTICITY INDEX

This can be defined as the numerical difference between the liquid limit and plastic limit. The plasticity index is expressed in percentage of the dry weight of the soil sample and also it shows the size of range of the moisture contents at which the soil remains plastic.

      The plasticity index also gives a good indication of compressibility. The greater the plastic limit the greater the soil compressibility (Ashworth 1966).

1.2 AIMS AND OBJECTIVES

      The aims and objectives of this project includes

i.            To study compressibility

ii.           To obtain the compressibility properties of soil in Maryland area.

iii.         To obtain data that may be used in predicting the rate and the amount of settlement of structures in the area.

1.3 SCOPE OF STUDY

The scope of this project is limited to obtaining the compressibility properties of soil in Maryland area.

1.4 SIGNIFICANCE OF THE STUDY

    i.        This project will help to understand the compressibility properties of soil in Maryland area which will reduce the problems that geotechnical engineers face in designing economic foundation for the required infrastructure in Maryland area.

   ii.        The compressibility properties of the soil in the area obtained from labouratory test might be used to estimate the magnitude and the rate of settlement of a structure or an earth fill in Maryland area.

1.5 COMPRESSIBILITY PARAMETERS:

To obtain the compressibility properties of soil in Maryland, labouratory test will be carried out to obtain.

i.            Coefficient of compression/compression index (CC).

ii.           Swell index (CS)

iii.         Coefficient of compressibility (AV)

iv.         Coefficient of volume compressibility (MV)