CHAPTER
ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
The development of soil erosion began when man
settled down and started turning pasture land into farmland. The intensive
exploitation of the land disturbed the natural soil vegetative cover and
exposed its, surface to the effect of erosive agents and to introduce such
forms of agriculture that did not destroy the land the devastation of land by
erosion often led to the down fall of civilization e.g in Mesopotamia Syria,
China and else where.
According
to Robert. M. (1984), Erosion is manifested by the determination of soil
surface effected by exogenous forces, especially water. Ice wind and, man as
the significant anthropogenic factor. The disturbance of soil surface is
accompanied by the removal of the detached soil particles by the force of kinetic
energy of some of the erosion agents, namely water and wind and the deposition
of this matter with a decrease in this energy. Erosion is caused by surface num
off and result complex natural process. Water erosion is caused by precipitation.
Areas with a low precipitation usually have a small surface num off because
precipitation water infiltrates into the soil is consumed by vegetation erosion
which may also be broadly cause by a natural factor organ.
It
can also be carried by improper channeling neglect of natural sewage systems
and obstruction of naturally sewage by buildings. Form land and other unplanned
structure causes a great deal of damage.
Although
the nature of soil within the area under consideration is mostly sandy with a
very low water storage capabilities. Practical observation orchestrated form
visit to those site prone to erosion have shown that their may be possibility
of erosion if the nun off water is not properly channel e.g the nature of the
soil. In sandy soil they can form a very good soil material but danger exist if
the water table is near or surface nun off is not adequately channeled. The
sandy easily eroded a way from it position their by causing or may lead to
fully erosion.
Furthermore,
erosion is seen as one of the most serious defects in contemporary residential buildings,
it is observed here that apart form it causing rapid destruction of structure /
buildings, it also result to severe damage to the soil and in severe case it
adversely affect the health of the occupants.
1.2 STATEMENT
OF PROBLEM
A
certain condition or factor can make a soil or structure / building to loose
their Sharpe effectively or ineffectively attain their maximum structural physical
and economic life span. It has been seen that a number of fact observed to be
responsible for the in-adequate or in-appropriate functioning channeling of
sewage surface nun off water at the due time. These in turn expose the building
site to the danger of erosion which accelerate their dilapidation. Among the
factors or improper channeling / neglect of natural sewage system and
obstruction of natural sewage by building without following the local
authorities rules dropping of refuse in the drainage ways. Erosion plays a critical
role in dilapidation of building and visible in construction industry as one of
the most serious defect in contemporary residential buildings. All soils can
suffer erosion but some are more vulnerable than others. Soils with dispersible
subsoils, for example, are subject to serious erosion by funneling and gully
formation.
1.3 RESEARCH AIMS AND OBJECTIVE
The major purpose of
this study is to determine. The effective way of controlling erosion in a
construction site prone to erosion problem.
1) Identity
the various causes of erosion in building sites.
2) Examine
the appropriate materials and (new and old) used in controlling the erosion.
3) Determine
the most appropriate materials and techniques required for the controlling it.
4) To
recommend measure if implemented will lead to effective control of erosion in a
construction
1.4 RESEARCH QUESTIONS
The
study sought to answer the following research questions
1) What
are nature and various causes of erosion in building sites
2) What
are the process to be applied in erosion control.
3) What are the various types of materials to be used in
controlling erosion
4) If
implemented will lead to effective control of erosion in an erosion prone site
1.5 SIGNIFICANT
OF THE STUDY
The significance of this study shall include the
follow:
1) Contractors
and engineers shall know how to control erosion in an erosion prone site.
2) The
engineers and the general public will because more aware on the importance of
erosion control in a site.
3) Lecturers,
students consultants and other stakeholders in the construction industry will
be theoretically & technically equipped on how to control erosion in an
erosion prone construction site.
1.6 STUDY
OF AREA
This
study was delimited to the problem of erosion in a site prone to erosion. It
focused on the type and magnitude of erosion at site in Anambra state and also
looked at the specific remedial techniques to that building site will function
effectively and efficiently. Attempt should be made to look into laboratory
experimentation of the material used for effective control of erosion in building
site prone to erosion. Ekwulobia erosion is gully erosion-gully erosion is of
concern due to periodically intense rainfall and a large average of erodible
soils. Effective design of gully control system must consider the gully network
as a whole and be based on geomorphologic indicators such as type of network,
order and stage of development.
1.7 DEFINITION
OF TERMS
According
to Grolie (1990). Erosion is the wearing away of the earth surface by the
action of water.
According
to Milos Holy (1987). Building is permanent or temporary structure enclosed
within exterior walls and a roof and including all attached apparatus.
Equipment and fixtures that cannot be removed without cutting into ceiling
floors or walls. In the year 1960 Bernard Huss define soil as the top layer of
the earths surface in which plants an grow consisting of rock and mineral
particles mixed with decayed organic matter and having the capability of
retaining water.