CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Some aspects of Civil Engineering is devoted to the planning and construction of facilities to drain the high ways or streets and carry run-offs. Removal of surface water from the road or street is known as surface drainage; drainage as distinct from plumbing is a system which collects waste products from baths. Wash – basins, water closets and sinks together with rain and discharges into public sewers, septic tanks, soakaways or cesspools.
The construction of drain is therefore principally concerned of the Manson. It is accomplished by constructing the road so that it has a crown and by sloping the shoulders and adjacent areas so as to control the flow of water either towards existing natural drainage, such as open ditches, or into a storm drainage system of catch basin and underground pipes. If a storm drainage system is used as it would be with city streets, the design Engineer must give consideration to the total area drainage unto the street, the maximum rate of run-off expected, the duration of the design storm, the amount of ponding allowable at each catchments area and the proposed spacing of catch basin along the street. From this information the desired capacity of the individual catch basin and the size of the underground piping network are calculated.
In designing facilities to carry run-offs from pavements, the Engineers must determine the area to be drained, the maximum probable precipitation over the drainage basin, the highest expected run-off rate, and then using this information must calculate the required capacity of the drainage structure.
Generally designs are made adequate to accommodate not only the largest flow ever recorded for that may be expected under the most adverse conditions for a given number of years. Factors considered in calculating the expected flow through a culvert opening include the size, length and shape of the entrance and down stream end of the conduit, the maximum allowable height of water at the entrance, and the water level at the outlet.
There is a trend to use designs that permit drainage structure yard. Such procedures permit better control of the work. For example with recast concrete pipe section, it is often possible to avoid building small box culverts in the field. Circular culverts of large diameter are now also constructed in the same way.
IMPORTANCE OF WATER DRAINAGE
Water drainage as an elemental part of Civil Engineering Construction plays an importance role which makes it very significant when it comes to the act of practicing maintenance culture.
To this end in every construction process, drainage should be given due consideration. In residential buildings, water drainage system is very importance so as to get rid of waste water and storm water from the building and thereby preventing the building from excessive dampness and by so doing providing good maintenance for the building.
Aside the fact that drainage system in residential building prevents excessive dampness, it also prevents excessive flooding. Another area in construction where drainage system can highly be appreciated is road and embankment construction. In road construction, water drainage are primarily designed to prevent excessive flooding of the paved surface thereby preventing wearing away of the surface and also make it more accessible during and after storm.
In the light of all these significant roles played by water drainage system, necessity has made it mandatory for any existing structure or proposed structure to have a water drainage system.
Resolving a water drainage system involves a lot of activities especially where the water drainage is to control excessive flooding or where it is to be designed for water logged area. The designing water drainage system there is need to anticipate the position of future structure erections so as not to hinder the aesthetic nature of future construction process.
Another importance fact is that for good effective water drainage system to be developed, there is need to construct a filter along the drainage channels because of the retention capacity of the soil within the campus area. The soil consist mostly later tic clay which has the ability to retain water for a long period of time. As this will be detrimental to the life span of the water drainage channel to be constructed, it is that masonry lining for the water drainage channels be constructed also.
1.2 OBJECTIVE OF THE STUDY
The objectives of the study work shall cover all the vital aspect of the drainage problems system. The first stage of this project work shall include the reconnaissance survey of the area covered by the campus, nothing the land scope and modal points ways, the effects of flood and erosion more prevalent, the catchments area and tributaries of the storms water that constitute the major part of the erosion and flood because it is quite noticeable that during the raining seasons that most of the road leading to campus and within the campus becomes in-accessible for motorists and part of the building, lecture rooms are highly flooded.
The next is to found out which type of the drainage system exists and the orientation, direction of the drainage channel.
Another objective where the study is going to lover is the type of hydraulic drainage design, the study shall also highlight the serviceability and cost effectiveness of the method adopted that is to say whether the design is made of press-stressed concrete or in-site concrete.
On the reasonable part of it, this study shall highlight more on the solution to this water drainage problems.