|dc.description.abstract||During the project Ferry-free coastal route E39, directed by National Public Road
Administration, NPRA, seven ferry-crossings are intended to be replaced by straight
crossing. One of these is Bjrnafjorden, where a proposed crossing is a multi-span
suspension bridge, supported by two tension leg platforms, TLPs. A simplied
model of this proposed crossing was created in Abaqus/CAE. Further, three additional
models were created to study how the number of supports and alteration
of cross-section aect the responses.
The rst two horizontal eigenfrequencies were compared to available eigenfrequencies
from NPRA. All models had higher eigenfrequencies, which indicates that the
models are stier, or that the mass and added mass are smaller, or a combination.
For the static analysis, three loads were applied. These were current at the
and trac and wind along the bridge. The environmental loads were determined
for 1-year, 50-year and 100-year return periods. The longitudinal and vertical displacement
along the bridge, in addition to bending moment, were determined for
every model. When the number of supports were increased, the vertical displacement
was signicantly reduced, while the largest vertical displacement occurred
for the model with reduced thickness of the horizontal beams in the cross-section.
This was also true for the longitudinal displacement when only the environmental
loads were applied.
For the dynamic analysis, an incoming harmonic wave was applied in horizontal
and vertical direction at the
oater. Two wave periods were utilized; the rst is a
feasible period and the second is the rst obtained eigenperiod. Resonance caused
signicantly larger motions for the
oaters. Generally, a reduction of the crosssection's
thickness on horizontal beams resulted in an increased sway response,
while the largest response in heave occurred for a reduced cross-section height.||