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The old bridge across Storstrmmen

was completed in 1937. However,

due to heavy increases in road trafc

on highway E4, which connects

Scandinavia with continental Europe,

a new four-lane motorway bridge

connection has been built.

With a total length of 3322 m, this

bridge complex is one of the longest

in Europe. It consists of two bridges,

a northern bridge from Zealand to the

small island of Far and a southern

bridge from Far to Falster. The north-

ern bridge has twenty 80 m spans

and a total length of 1596 m. The

southern bridge has a total length of

1726 m which includes a cable-

stayed bridge with a navigation span

of 290 m, side spans of 120 m and

80 m spans for the approaches.

The Far Bridges, Denmark

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33-1702-006e-00a

Superstructure

The highway carried by the bridge is

designed as a 4-lane motorway with

emergency footways on either side

supported on cantilevered brackets.

The effective width between the crash

barriers is 9 m in each direction.

Basically, the cross-sections of the

two bridges are identical, except that

the central reserve on the Far-Falster

bridge is 1 m wider than on the Zea-

land-Far bridge to allow for the ca-

bles of the cable stayed bridge.

The cross-section of the bridge

girders consists of a single-cell box

composed of a few main elements

which, with few variations, are used

over the entire length of the bridge,

thereby allowing industrialized fabrica-

tion.

Project period: 1980-1985

Client: Ministry of Public Works,The Road Directorate

Services:

Bid design

Detailed design and

construction supervision of

steel superstructures

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The main elements include:

orthotropic deck panels with trape-

zoidal stiffeners at intervals of about

0.6 m bottom and side panels with trape-

zoidal stiffeners at intervals of 1.0 m

uniform transverse bulkheads at in-

tervals of 4 m throughout the bridge

and special heavy bulkheads at the

piers.

Special attention has been paid to the

development of suitable connections

between exterior panels and bulk-

heads in order to simplify mass pro-

duction and industrialized assembly

techniques.

Corrosion Protection

The exposed surface of the box gird-

ers is only 15% greater than the area

of the bridge deck and the smooth

painted outer sides are easy to in-

spect and maintain.

The inside surface which, with a to-

tal area of more than 300,000 m,

represents 80% of the total area of

the steel (excluding road surfacingarea) is not painted. Dehumidication

plants maintain the mean humidity

below about 40% RH, ensuring that

corrosion does not occur.

This method of corrosion protection

results in a net reduction in paint

costs corresponding to about 8-10%

of the construction cost of the super-

structure and also results in very low

maintenance costs.

Cable-stayed Bridge

The girder is suspended in accord-

ance with the multi-stay principle with

the individual cables closely spaced.

The small cable forces of this system

eliminate the need for large compli-

cated transverse girder structures,

which do not normally permit rational

fabrication.

The 18 stays (per half-bridge) are

arranged symmetrically about the py-

lon and are anchored in the bridge

girder at intervals of 16 m.

Aerodynamic stability of the bridge

has been tested using models in a

wind tunnel with several different

crash barrier types. Furthermore, criti-

cal erection phases have been tested.

The stays are parallel wire strands

(PWS) consisting of a number of 7

mm dia. wires, the ends of which are

anchored in special fatigue-resistant

Hi-Am anchor heads. The cable-stays

are protected by cement mortar

grouted UV resistant PE-ducts.

At the top of the pylons, the stays

are anchored in a steel anchoring ele-

ment which is post-tensioned to the

concrete legs of the pylons.

Box Fabrication

The girder structure is fabricated at a

shipyard in 80 m full span sections

and 16 m sections for the navigationspan of the cable-stayed bridge. A to-

tal of thirty-nine 80 m sections, twelve

16 m section, and two nal 10 m sec-

tions have been constructed.

Erection

The bridge girders are oated by

barge to the bridge site approximately

80 km from the shipyard in Nakskov.

After positioning of the barge be-

tween the piers - with the 600 t girder

segment positioned at a high level -

the girder is lowered onto temporary

supports by hydraulic jacks.

In the cable-stayed bridge, two 80

m segments are used for each 120 m

side span with 40 m cantilevered into

the main span from the pylon. The re-

maining 210 m of the main span are

erected by alternate erection and

welding of 16 m long bridge seg-

ments to each cantilever and erection

of cable-stays, until continuity isachieved at midspan.