The purpose of this project is to obtain knowledge about construction of ortotropical bridges. In
this project a specific ramp in Hirtshals needs to be built, and thus two different designs will be
compared.
Both ramps measures 27 × 19 m, with a 5° bend in the last 5 m. The first design consist of two
main girders in each side of the ramp, and three cross girders at the dock, bend and ending of
the ramp. On the inside of the ramp trapezoidal ribs are placed to make the construction more
rigid. The second design consists of the same frame, though a bit smaller. The main difference
here is that inside the frame there will also be crossmembers with holes for smaller trapezoidal
ribs.
The simple ramp is controlled with classic analytical calculations with regards to the Eurocode,
specifically 1 and 3. It is controlled against deflection, static failure and failure caused by fatigue.
This ramp is also controlled by using the finite element method. The analysis is made using the
software Inventor, and meshing will be done using 3D solid elements. The FEM analysis will be
controlled against the same parameters as the analytical model was.
The other ramp is only checked by using the FEM, due to the higher complexity of the
construction. The same settings and control parameters as the simple ramp is used. It is then
confirmed that both ramps will be safe, in terms of the required demands.
To compare the two ramps the production is explained, and the different welding methods is
accounted for. All the steel and welding material needed for the two ramps is summarized and
compared, which reveal that the complex ramp uses slightly less material, but ultimately needs
more welding work. Thus is it concluded that the complex ramp is deemed optimal, though more
specifications of the welding work is needed to make the conclusion fully clear.