PROBLEM STATEMENT
The problem thus posed in this work is that of dimensioning,
of the design of the cross sectional profile of a roadway in urban area and of
its impact on the output, on the functioning of the section road to
consider.
It is therefore question of proposing a dimensioning which
depend on the frequency of use, on function of an urban road way and
neighboring social activity; of knowing how to organize, to set out
distribution of a roadway (numbers of ways, installations to be brought) in
order to make it practical according to the zone of localization and the time
period considered, especially when it is known that the urban environment in
Cameroon is characterized by a remarkable disorder.
In fact, for any road study:
· The alignment is a sight in plan of the highway design
(the center line of highway, various widths) in its environment support. It is
composed of a succession of segment of right-hand side (general alignments)
connected by curves which are either of the clothoïdes or of the circles
or a combination of both (clothoïdes and circles)
· The longitudinal section is a cut carried out
longitudinally along the axis of the road (defined by the alignment) and
perpendicular to the original ground. It consists of a succession of slopes and
slopes connected by circular or parabolic elements and is conceived after the
final choice of the alignment
· The cross sectionof a road is represented by the layout
of the roadway and the original ground on an orthogonal vertical plan with the
center line of highway. In other words, it is a cut perpendicular to the center
line of highway and original ground (on the longitudinalprofile). It gives as
other information, the various dimensions of original ground, projects, the
gauge (width of the road), etc.
Thus, talking of cross sectional profile for a road project
mean to integrate these three defined terms because the study of the cross
sectional profile of a road could not be isolated from the
longitudinalprofilewhich itself is dependent on alignmentof this road.
But, the problem as posed up will treat mainly dimensioning of
the gauge, of the width of the roadway. In fact, throughout our document, we
will speak about cross sectional profile with regard to the distribution, the
number of ways and dimensions which comprise the roadway itself and various
installations which can be annexed there in order to improve its
effectiveness.
JUSTIFICATION OF THE CHOICE
OF THE TOPIC
Our study isinfluenced by a contextin which Cameroon fixed
itself as objective to be an emergent country at horizon 2035. The reaching of
this major goal will be done by the achievement of multiple secondary or
specific objectives as presented in the DSCE, in particular those having link
with the urban development such:
· The development of the urban infrastructures
(construction of 150 km roadway system and construction of 17000 social
housing),
· The maintenance and the rehabilitation of the urban
infrastructures,
· Improvement of the access to the basic urban
services,
· Control of the occupation of the ground,
· The protection of the vulnerable social groups and,
Thus, the urban development being made mainly by creation,
equipment and the maintenance of the road infrastructure, it is therefore in
this spirit that the DSCE envisages a number of km of urban roadway systems
built since 2010 which will pass to 63 km in 2015 to 150 km in 2020.This urban
growth will inevitably be done by the means of an increase in urban population
(estimates making state of a rate of urbanization of 57,3% in 2020 according to
the DSCE), and thus, of important urban displacements.
However, in this policy of the improvement of the frame of
life on the national territory in general and in the various urban centers in
particular, how to boost or how to improve the output of our cities which are
not very productive with the sight of the multiple problems to which they face
such as difficulties of installation of effective and durable transport system,
the problems of traffic jam, etc.? In order to bring a solution to these
problems, we propose to focus throughout this work on the installation of the
roadway system which ascertains to be the structure carrying the urban
development. How to improve the characteristics of the roads in our cities in
order to improve their productivity? Which is the impact of the profile across
a road in urban environment?
Such are the various questions which found the
justification of the choice of the present thesis.
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