EFFECTIVE STRATEGIES OF CONTROLLING EROSION IN A CONSTRUCTION SITE

1.1 Introduction

Construction site soil erosion is a natural process in which particles of soil are moved by wind and water, and displaced to another location. When erosion occurs naturally, soil is relocated at about the same rate it is created, so no harm is done to the environment. Erosion is one of the biggest concerns of earth's land surface. It has many impacts on agricultural production and also in all engineering and construction industries. Erosion can be caused by multiple reasons, and every situation has a specific solution depending on the severity of the problem. Soil erosion is a naturally occurring process that affects all landforms. The causes and effects should be studied in order to control soil erosion.

As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitations of the Study and Definition of technical terms.

1.2 Background of 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 elsewhere.

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.

Erosion, whether it is by water, wind or tillage, involves three distinct actions – soil detachment, movement and deposition. Erosion takes place all the time naturally. The erosion potential of any surface is determined by four basic factors: soil characteristics, vegetative cover, topography, and climate. 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 there 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 away 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 from 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.

Any changes made in the characteristics of the soil itself, are detrimental to infiltration, runoff patterns, and stream flow characteristics. The most effective form of erosion control is to minimize the area of disturbance, retaining as much existing vegetation as possible. This is especially important on steep slopes or in the vicinity of water bodies, where no single measure will adequately control erosion and where receiving environments may be highly sensitive. Match land development to land sensitivity. Watch out for and avoid areas that are wet (streams, wetlands, springs), have steep or fragile soils.

Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Effective Strategies of Controlling Erosion in a Construction Site.

1.3 Statement of Problems

Investigation revealed that 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 accelerates 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.

1.4 Aim and Objectives of Study

The aim of the study is to examine the Effective Strategies of Controlling Erosion in a Construction Site. In achieving this aim, the following specific objectives were laid out as follows:

1. To determine the most appropriate materials and techniques required for the controlling it;
2. To examine the appropriate materials and (new and old) used in controlling the erosion;
3. To identity the various causes of erosion in building sites; and
4. To recommend measure if implemented will lead to effective control of erosion in a construction.

1.5 Research Questions

The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:

• What are nature and various causes of erosion in building sites?
• What is the process to be applied in erosion control?
• What are the various types of materials to be used in controlling erosion?
• If implemented will lead to effective control of erosion in an erosion prone site?

1.6 Research Hypothesis

In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.

Hypothesis One

• H0: There is no significant factor inhibiting the effective control of erosion in a building site
• H1: There is a significant factor inhibiting the effective control of erosion in a building site

1.7 Significance of 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, student’s consultants and other stakeholders in the construction industry will be theoretically & technically equipped on how to control erosion in an erosion prone construction site.

This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.

1.8 Scope of Study

The scope of the research is focused on the Effective Ways of Controlling Erosion in Nigerian Building Site. This study was delimited to the problem of erosion in a site prone to erosion. It concentrates 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.

1.9 Limitations of the Study

During the course of this study, many things militated against its completion, some of which are:

1. Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
2. Research material: availability of research material is a major setback to the scope of the study.
3. Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
4. Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).

1.10 Definition of Terms

Erosion: It is the wearing away of the earth surface by the action of water.

Building: It is permanent or temporary structure enclosed within exterior walls and a roof and including all attached apparatus.