Abstract:
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The aim of this thesis is to respond to a need every day more emerging which is to create links
connecting to open trade and social routes. The challenge is to avoid a distance of about 2.000
meters by constructing a hybrid bridge, a fact that has not happened so far because of the
limitations that the different types of bridges present.
Nowadays it is being built the 3rd Bosphorus Bridge and it is the most significant example of a
hybrid bridge. The difficulty resides in becoming a motorway/railway bridge rising a total length
of 2.164 m and being then the longest one in this category. The objective here will be to
reproduce similar conditions of this superstructure but for this we will have to take into account
some considerations.
Broadly speaking, this study will be divided into different parts: a first part that will present the
different characteristics of both a suspension bridge and a cable-stayed bridge, a second part
where we will present the two models that we will study (2D and 3D), a third part with the
construction phases of the bridge and a final part where both static and dynamic equilibrium
will be verified. Most of the parts will be interrelated between them so we will see that there is
not a strict order in this thesis.
Anyway, for the first part we will be able to use all the existing information and we will just
expose all the different variables in order to choose between them in the second part. In this
second part we will use the Finite Element Method for the 3D Model and we will adapt this to a
2D Model choosing the final different cross – sections we will adopt, the required geometry for
the different parts and the existing elements in SAP2000 to model the whole structure. The third
part will be divided in two parts: one focused on the theoretical explanation about how to carry
out the construction process and another one focused on the necessary calculations to reach
consistent results. Finally it will be verified firstly the static equilibrium of the main parts of the
structure accomplishing the Service Limit State (S.L.S) and the Ultimate Limit State (U.L.S), and
secondly it will be carried out the dynamic analysis introducing the concept of aero - elasticity
and studying this phenomena for three different models (2D Model, Fish-Bone Beam Model and
3D Model).
However, we will be more focused on guarantee the static equilibrium designing and studying
the different possibilities we can have in the different components of the bridge. |