SOIL SURVEY IN ENUGU METROPOLIS
(A CASE STUDY OF COAL CAMP)
The soil investigation is the research carried out to assess the properties of water in a given volume of soil, the ratio of the weight of given volume of soil sample to the weight of an equal volume of water at a standard temperature and pressure, by knowing the percentage of the various grain sizes present in a soil, to distinguish between silt and clay, the quality and suitability of the soil, the rate with which water flow through saturated soil sample and the value of cohesion and the value of angle of internal friction of the soil. From notable sources in Enugu. Sample of the soil were obtained from jamboree, new site, chest unit unth and bunker, all in coal camp area , enugu state. These samples were tested; compared against each other and with standard specifications – BS and ASSHTO. The analysis revealed that the soil from the four different sources are good in carrying any load.
TABLE OF CONTENTS
Title page i
Approval page ii
Table of contents vi
1.0 Introduction 1
1.1 Back ground of study 2
1.2 Background of study 3
1.3 Aims and objectives 4
1.4 Statement of problems 5
1.5 Significance of study 5
1.6 Scope and limitations 6
1.7 Collection of samples and laboratory testing program 6
2.0 Literature review 8
2.1 Soil 8
2.1.1 Soil survey 8
2.1.2 Historical soil survey 9
2.1.3 Soil structure 13
2.1.4 Soil texture 14
2.1.5 Properties of soil particles 15
2.1.6 Water holding capacity 15
2.1.7 Permeability 15
2.2 Soil compaction 15
2.2.1 Soil pH 17
2.3 Soil organic matter 17
2.3.1 Soil sampling, 18
2.3 Soil formation 20
2.3.1 Fine – grainsed soils 21
2.4 Soil classification 22
3.0 Methodology 23
3.1 Equipments 23
3.2 Boring operations 24
3.3 Sampling 25
3.4 Description of the site 25
3.4.1 Location and description of sample collected 26
3.4.2 Extent and depth of boring 29
3.4.3 Laboratory test or investigations 29
3.5 Sieve analysis 30
3.6 Natural moisture content determination test 32
3.7 Specific gravity test 35
3.8 Atterberg limits tests 39
3.8.1 Procedure for liquid limit 41
3.8.2 Procedure for determination of the plastic limit 44
3.8.3 Plasticity index 46
3.9 Compaction test 48
3.9.1 Optimum moisture content (OME) 49
3.9.2 Maximum dry density 50
3.9.3 Procedure using British standard test 51
3.9.4 CBR test 53
3.10 Permeability test 54
3.11 Triaxial test 63
4.0 Analysis of results 70
5.0 Discussion of results 71
5.1 The Atterberg limits 71
5.2 Specific gravity 72
5.3 Natural moisture content 72
5.4 Compaction 73
5.5 Sieve analysis 74
5.6 Permeability test 74
5.7 Consolidation test 76
6.0 Conclusion and summary 78
6.1 Recommendation 76
Civil engineering profession encounter soil in diverse ways uses soil as a foundation to support structures and embarkments. Utilises soil as a construction material and must design structures that retain soils from excavation and underground openings.
The answer to a problem in soil engineering is normally obtained by first determining the properties of soil in question and employing these properties to work out a solution. It ies necessary that the soil should be capable of sustaining the applied load without serious deformation and damage, and should retain its strength and stability indefinitely, therefore to meet this requirements an answer to a problem in soil engineering is sought. Hence in planning design and construction of any engineering structure, the engineering should consider supremely important, a satisfactory design with respect to safety and function. To this end, extra care should be taken in any design so as not to defeat the purpose for which the structure was constructed.
Since the soil in every site is different, the soil involve in each different problem must be evaluated. Often, this evaluation can be approximated from a knowledge of the geology of the site or from experience with similar soils. This gave rise to soil surveying and these properties being determined by laboratory tests. More so, and because of the great variety of subsoil condition that may have an adverse effect on the stability of the structures, the design of such structures constitutes a problem. This makes it all the more important to know the soil properties and hence the justification of the project whose purpose is to determine by field and laboratory experiments.
The exercise is therefore designed to provide the necessary data that may be required in the course of some engineering works. This is necessary because of the need to introduce and erect modern structure which is bound to involve some soil problems.
“The practical purpose of soil survey is to enable more numerous, more accurate and more useful predictions [of land performance] to be made for specific purposes than could have been madeotherwise [i.e., in the absence of location-specific information about soils].
Lastly this project deals with the soil survey and laboratory testing of soils in Enugu state urban area, a case study of Coal Camp sub urban area using only four boreholes at different locations.
1.2 BACKGROUND OF STUDY
Soil survey is a vast area of study or analysis. It depends on one area of discipline. This survey is used to develop some engineering properties that is used to establish some parameters that is used for geometrical design and this establishment depends on the type of soil one is dealing with.
This survey was done a group of three(3) persons, using coal camp sub-urban area as a case study. Samples for the survey was collected from four different locations establishing four boreholes at different depth.
: New site, coal camp --------- borehole 1 : jamboree behind coal camp maternity-----borehole 2 : Chest unit, UNTH, Enugu ------------------- borehole 3
: Bunker hill, coal camp ------------------ borehole 4
The test carried out on the samples are sieve analysis, specific gravity, moisture content, compaction, permeability, consolidation, atterberg limit and triaxial test.
In a situation where the area is water logged , other test that can be carried out are soil pH test, sodium chloride test and sulphate test..
1.3 AIMS AND OBJECTIVES
The main aim of our test is to have a comprehensive soil engineering map in enugu state urban metropolis. A case study of coal camp. The project aims at providing a well constructed soil survey for coal camp sub-urban which geotechnical engineers can relly on and carry out their engineering projects
To provide good parameter s for geotechnical designs.
To help reduce constant case of failure in construction works.
1.4 STATEMENT OF PROBLEMS
In construction works , structural or geotechnical engineers have neglected the vital need for soil test or soil survey. The neglect has lead to constant cases of building collapse, failure of newly constructed roads, bridges, culverts etc.
1.5 SIGNIFICANCE OF STUDY
Having seen the problems of neglect of soil survey, i feel like contributing to this vital study of geotechnical engineering by collecting the samples, identifying and describing them and carrying out necessary laboratory test to help engineers design to safety.
1.6 SCOPE AND LIMITATIONS
The project aims at determining the soil engineering properties, identifying and classifying them.
Due to the vast area to cover, it intends to surveying of soil only in this particular area of enugu state using only four (4) boreholes.
1.7 COLLECTION OF SAMPLES AND LABORATORY TESTING PROGRAM
The test carried out in this project was on distributed soil sample.
This implies collecting soil samples that are disfigured their natural shape.
Soil samples were collected on three (4) trial pit at different locations within the coal camp Enugu. A total of three (6) samples were collected from the trial pits using pick are and spade. The samples were taken at 1.0m depth intervals. The samples were put in sack bags and labelled 1,2A,2B,3A,3B and 4. The samples were spread on the floor of the soil laboratory and stones removed for seven (7) days to allow for air drying.
The laboratory testing program comprises seive analysis, compaction test, specific gravity, atterberg limit tests, moisture content test, permeability, consolidation test.
The objectives of the laboratory testing program were
1. To obtain a general information regarding the nature of the soil and their variation with depth.
2. To obtain information regarding the strength characteristics of the soil.
To obtain information which will enable engineers to group soils according to their appearances of the purposes of complying different soils.