Two-part superstructure
made entirely of steel
Svinesund, link
SUPERSTRUCTURE
One bridge - looks like two
The superstructure of the bridge consists of two box beams
made of steel. The two halves of the superstructures will
be joined by a cross-member at each bridge support.
Bridge sections 24 metres long and five metres wide
will be delivered from the workshop. They will be made
of steel plate, which is 12-40 mm thick and has been reinforced with longitudinal profiles.
Two sections will be welded together to produce a 10metre-wide deck. Over each bridge support, two decks
will be joined together via a cross-member to produce a
section 28 metres wide and 24 metres long.
The cross-members are steel boxes, eight metres wide
and three metres high. They will be anchored in place by
powerful cables that will be fixed to clamping struts inside
the bridge supports – and thereby unite the superstructure with the supports.
In the arch section, the decks will be assembled on
either side of the arch. The two halves of the superstructure will be tight sidewise to the arch with cables without
an additional cross-girder, so that the arch will rise between the carriageways without visible disturbances.
Large and strong but looks light
To reinforce the impression of lightness, the superstructure narrows “aslant” towards the outer edge.
The wide intermediate space between the decks lets
through sun, light and precipitation and makes the bridge
less dominant from the underside.
Slightly curved to the west
Each deck will have its own connection to the ground and
the abutments will act as the transition between the bridge and the ground. The decks on the southern side are
about 360 metres. On the northern side, their length varies, 68 metres and 75 metres, and the abutment is split.
The arch section of the superstructure is 188 m. The
road and the bridge on the Swedish side curve, so motorists from the south will have a wonderful view of the
entire bridge.
Inspection points
Interior lighting and the opportunity to walk along the
whole of the bridge beam and transverse bulkheads will
make inspections easy in the future.
Correct relative humidity simplifies maintenance
The interior will not be painted. A dehumidifying system
will keep the relative humidity at a level that prevents
corrosion.
Substructure made of reinforced concrete
The intermediate supports are simple, rectangular concrete columns. As a result of the ground conditions, their
width and height vary, but their dimensions increase towards the base. The abutments take over the outer shape
of the superstructure to continue its slender impression.
The abutments and intermediate supports will be
equipped with doors, interior stairs, lighting and so on to
enable future inspections.
Vägverket Region Väst
SE 405 33 Göteborg, Sweden
+46 31 63 50 00 www.vv.se
Statens Vegvesen Region Øst
Postboks 1010 Skurva, NO 2605 Lillehammer, Norway
+47 69 24 35 00 www.vegvesen.no
Norwegian Public
Roads Administration
Decks launched over supports in Sweden...
Stepwise launch on southern side
On the southern side, the decks will be launched; in other
words, they will be pushed out in stages over the bridge
supports. A launching station with auxiliary supports,
hydraulic installations and so on will be build behind the
abutment.
This station is about 100 metres long so that three
sections can be assembled and launched simultaneously
to reduce the number of launching stages. The bridge
piers will be reinforced with auxiliary steel structures
which will brace the superstructure. Hydraulic jacks will
push out the decks, 0.5 metres at a time. They will move
easily on sliding bearings made of teflon on the auxiliary
supports.
At the very front, there is what is
known as a launching nose. This is a 35-metre
steel structure that compensates for the deflection of
the deck. After each launching stage, the bridge will be
fixed in place provisionally.
The launching level is about 0.50 metres above the final
superstructure level. When the entire structure is in its
final position, it will be lowered and fixed in place. The
decks will be launched to a point behind support 5.
Launching is expected to be completed in the spring of
2004.
... and lifted into place by a crane in Norway
The individual sections of the superstructure will be
transported by truck to the assembly point on the Norwegian side. They will be placed on a fixed scaffold and
welded together directly in their final position. This will
require far more auxiliary supports to brace the decks
during assembly than will be needed on the Swedish
side. Accessibility in parts of the site is very poor and sites
will therefore be constructed for the 500-tonne cranes
that will be needed for handling and assembly of all segments.
Temporary harbour at the site
The superstructure will be constructed in Germany in
sections measuring 24 x 5 metres and weighing around
80 tonnes. They will be transported by sea from Rostock
to a provisional harbour in a small bay on the Swedish
side.
They will then be unloaded using a gigantic trailer,
which will drive out on a barge to the ship via a gangway
on pontoons. The barge measures 60 x 15 metres and
will be anchored to the rocks and pontoons.
Arch section hoisted into place in the arch
Assembling the arch section
The superstructure that will be suspended in the arch
will be installed last. Five sections will be welded into one
section, measuring 127 x 28 m, in Halden harbour. From
there, the welded section will be transported by sea to
the bridge site.
Using temporary lifting devices inside the arch, this
section will be hoisted up and connected to the cables
in the arch. These cables follow the shape of the arch
and the distance between them increases towards the
attachment points in the cross-member. At supports 6
and 7, the beginning and end of the arch section, the
last sections will be braced and attached to the arch
using prestressing cables.
The cable entries in the arch will be extra large in
order to accommodate both the permanent bridge cables
and the wires that will lift the arch section. When the
assembly work is completed, these wires will be cut.
When the wires are spun, a spinning agent (zinc paste)
is added and, in combination with the profiled wires,
this makes the structure completely watertight. So no
extra sheath is needed around the cable. This is advantageous from an inspection angle and important in
terms of aesthetics and the desire to keep the dimensions as small as possible.
Detailed work
Once the superstructure has been completed, work will
begin on insulation, surfacing and final painting, together with the assembly of balustrades and transparent
noise-reduction screens.
FACTS SUPERSTRUCTURE
Bridge cables with minimal dimensions
The cables have a diameter of 90 mm and are of what is
known as the locked coil type. The coil has a core made
up of a number of 5 mm seamless steel wires. Around
the core, there are several layers of wires with profiled
cross-sections that lock into one another. Both types of
wire are galvanised.
Total length of bridge
704 m
Steel
7,430 tonnes
Cables in arch section 6x2 cables 14.5 m-27 m long
Width of bridge, total
28.2 m
Vertical clearance, approx.
55 m
SPAN 247 m
TOTAL LENGTH OF BRIDGE 704 M
SUPPORT WALL
ABUTMENT
BRIDGE SUPPORTS
SUPERSTRUCTURE
CROSS-MEMBERS
ACCESS BRIDGE SWEDEN, 363 m
ABUTMENT
ARCH SECTION, 188 m
SUPPORT WALL
ACCESS BRIDGE NORWAY,
128 M/142 M
The superstructure consists of two separate decks which will be joined at the bridge supports and cables
in the arch section. There is a space of eight metres between the bridges.