CHAPTER ONE
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)