Thesis Abstract

Abstract
The constant head permeability test is a crucial method for determining the hydraulic conductivity of soil samples. This study aims to assess and compare the results of constant head permeability tests conducted on various soil samples in Abak Local Government. The research involves collecting soil samples from different locations within the study area and subjecting them to constant head permeability tests in the laboratory. The hydraulic conductivity values obtained from the tests are used to evaluate the permeability characteristics of the soil samples. The findings of this study provide valuable insights into the variation in hydraulic conductivity among different soil types in Abak Local Government. By comparing the results of the constant head permeability tests, the research sheds light on the permeability properties of soils in the area and their implications for various engineering applications. Understanding the permeability of soils is essential for designing effective drainage systems, evaluating groundwater flow, and assessing the stability of structures built on or in contact with the ground. The methodology involves following standardized procedures for conducting constant head permeability tests on soil samples. The tests are carried out using a permeameter apparatus to measure the flow of water through the soil specimens under constant head conditions. The data collected from the tests are analyzed to determine the hydraulic conductivity of the soil samples and to compare the permeability characteristics of different soil types. The results of the study highlight the significant differences in hydraulic conductivity observed among the soil samples tested. These variations underscore the diverse nature of soil permeability in the study area and emphasize the importance of site-specific testing for engineering projects. The research findings contribute to the body of knowledge on soil mechanics and geotechnical engineering, providing valuable information for future construction and infrastructure development in Abak Local Government and similar regions. Overall, this study enhances our understanding of soil permeability through the assessment and comparison of constant head permeability tests on different soil samples in Abak Local Government. The research findings have practical implications for geotechnical engineering and underscore the importance of considering soil permeability in construction and environmental management practices.

Thesis Overview

INTRODUCTION

BACKGROUND OF STUDY

The facility at which a fluid is able to travel through soil pores is referred to as permeability. A material is permeable if it contains continuous voids. Binod Tiwari (2008). All materials such as rocks, soils, concrete, etc. are permeable, the flow of water through all of them obeys approximately the same laws.

The permeability of soils has a decisive effect on the stability of a foundation, seepage loss through embankments of reservoirs, drainage of subgrades, excavation of open cuts in water-bearing sand, rate of flow of water into wells and many others (Mante, 1960).

The permeability of a soil also has a great influence on plant growth since plants obtain their water and nutrients from the soil, plant growing on highly permeable soil may wilt if they are not watered regularly because water passes so rapidly through the soil that there is not enough stored in the soil pores for plant use. Soils of low permeability generally tend to be water-logged and are consequently poorly aerated, plants growing on such soils have enough water but not enough air, therefore they suffocate and die. Frederick (1963).

Apart from agriculture, knowledge of permeability is useful in the solution of problems involving drainage of airports, highways and playing fields, etc., uplift pressure beneath dams and buildings, landslides, seepage through earth dams, dewatering of excavated sites and many other problems (Mante, 1960).

Methods that are common for determining the coefficient of permeability can be classified under laboratory and field methods, but for the sake of this research, laboratory methods shall be considered. These are:

1. Constant Head Permeability and
2. Falling Head Permeability methods.

The various types of apparatus which are used in soil laboratories for determining the coefficients of permeability of soils are called permeameter. Apparatus used for the Constant Head Permeability Test is called a Constant Head permeameter and the one used for the Falling Head Test is a Falling Head permeameter (Murthy, 2005). The Constant Head Permeability test is more suited for coarse grained soils such as gravelly sand and coarse medium sand.

Permeability of soil controls the rate at which saturated soils undergo compression below foundations under external loads. Knowledge of permeability of soil is required in determining the discharge or yield designing of the well and hydraulic structures and through earth dams. Permeability is also required in designing filters used to prevent piping failure in earth dams, it also controls the stability of hydraulic structures.

Soils are characterized by swelling, depressions and lateral movement in the presence of water even under moderate wheel loads (Obeahon, 1993). Civil engineering practice and construction works in Nigeria depend greatly upon very large extent of good road networks.

The importance of permeability in many soil problems makes it desirable that it be measured as accurately and as rapidly as possible. Unfortunately, most of the present day methods available for the measurement of permeability take a considerable amount of time and succeed in giving only an estimate of it.

 

STATEMENT OF THE PROBLEM

The need for this study arises from the fact that poor lateritic soil, in their natural states are at best not suitable for sub-base, because it causes more damage to structures.

The study of the permeability of soils is important in soil mechanics, it is essential for calculating the quantity of underground seepage under various hydraulic condition. In common practice, the permeability coefficient is usually obtained by constant Head Permeability Test and is utilized in filtration, drainage, settlement and stability calculations. For any soil to be suitable for civil engineering projects, they must meet existing requirements (Amadi, 2010) constructions on such areas needs thorough research to find a cost effective way of stabilizing and utilizing them.

SIGNIFICANCEOF THE STUDY

The general objective of the study is to assess and compare Constant Head Permeability test on different soil samples.

The specific objectives of the study are:

1. Compare and determine Constant Head Permeability test on different soil samples.
2. To determine the relationship between soil permeability on different types of soil.

• To determine the coefficientsof permeability on different soil samples and their effects.

1. To perform a permeability test for fine grained and granular soils.

 

JUSTIFICATION FOR THE RESEARCH

Laterite has different properties – shrinkage and swelling, depending on location, some may not be good materials suitable for direct use in road and building construction in civil/geotechnical engineering project due to different properties they possess (Osinubi, 1995).

 

SCOPE AND LIMITATION

This research work will be limited to compare the laboratory test used to assess the constant head permeability on different soil materials, regarding the use of lateritic soil if used as fill material embankment.

Compaction test will be carried out using the compaction energies of British Standard Light (BSL). All other tests will be carried out with accordance to BS 1924 (1990) and BS 1377 (1990).

EXPECTED BENEFIT

The knowledge gained in the process of this research work will help in solving problems involving yield of water bearing strata, seepage through earthen dams, stability of earthen dams and embankments of canal bank affected by seepage, settlement, etc.

Other benefits include:

1. To find out the rate of consolidation and settlement of soil structures.
2. To estimate ground water flow and design pits for recharging

• To plan the method of lowering the ground water table.

1. To also calculate the uplift pressure and piping.
2. Serving as a standard thesis for academic research purposes.