Concrete Railway Bridges
ES-Consult has for several years designed concrete railway bridges for
The Danish Railway Authorities (earlier The Danish State Railways, DSB).
Most of the bridges built by The Danish Railway Authorities must be made
such that the construction causes the fewest possible inconveniences to
the traffic before, during and after construction of the bridge.
When the Great Belt Link between Funen and Sealand was finished, a higher
maximum speed of trains was introduced on the line between Copenhagen and
Århus. Therefore all level crossings on Funen have been abandoned
or replaced by bridges.
ES-Consult has assisted The Danish Railway Authorities in the design
of longitudinally pre-stressed concrete railway bridges on the line in
question. In order that the traffic on the line could proceed without serious
restrictions in the construction phase, a construction method was chosen
where the bridges were pushed sideways under the railway tracks. On the
railway section affected, the train speed was reduced for 11/2 month at
each construction site.
The work was carried out by building the bridge next to the permanent
way and support the railway track on a provisional steel structure on steel
piles. When the bridge was ready, the bridge was pushed sideways in under
the railway track. Then the steel piles were successively cut off, so that
the bridge deck gradually took over more and more of the load from the
track. The remaining steel structure was then replaced by ballast and the
speed restrictions were removed.
ES-Consult has furthermore designed 3- and 4- span concrete railway
bridges for The Danish Railway Authorities built in a more conventional
manner since they were constructed on the new permanent way in connection
with a future re-alignment of the railway over a shorter section.
On the railway line between the cities Skive and Viborg in Jutland,
ES-Consult has designed a 3-span concrete railway bridge with a length
of approximately 70 m. This bridge was built next to the permanent way,
and when the railway was closed during a weekend, the bridge, which weighed
approximately 1800 tons, was pushed into place. Then the track was re-established
and the railway reopened.
In order to perform the complicated working operations for building a bridge
under a railway in operation, a careful description of all working operations,
time schedules, and speed restrictions for the railway traffic was worked
out for each of the affected projects.