Symphony bridge
Encyclopedia
A symphony bridge or bridge symphony is a bridge
which combines the structural support systems of a suspension bridge
, a cable-stayed bridge
and a cantilever bridge
. No such bridges have been built, nor are there any specific plans, although the method has been considered for several bridges in Norway. It was developed collaboratively by the Norwegian Public Roads Administration
and the civil engineering consulting company Aas-Jakobsen
as a means of building bridges with spans between 1000 metre.
The design is based on two separate roadways which are connected by crossbeams. A symphony bridge would have two pylons, which would be circular in hollow cross-section. The center of the bridge would be supported by a central cable (unlike the conventional two side cables of a suspension bridge) connected to the deck via hangers connected to the crossbeams. The cross-beams and hangers are triangular in form. On both sides of the suspension section, the bridge would be built as a cable-stayed bridge with cables from the pylon. The areas closest to the pylons would be constructed with cantilever support. The designers have stated that the bridge would allow for greater wind stability, more drag, faster construction time, lower cost, and increased access for inspections and maintenance.
For the Hålogaland Bridge
, which is proposed to have a 1345 metres (4,412.7 ft) long main span, a symphony bridge was considered but was discarded after it was deemed too expensive at a projected cost of 2,380 million Norwegian krone
r (NOK), compared to NOK 1,860 for a suspension bridge. The proposed Storfjord Bridge
could be built as a symphony bridge.
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
which combines the structural support systems of a suspension bridge
Suspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century...
, a cable-stayed bridge
Cable-stayed bridge
A cable-stayed bridge is a bridge that consists of one or more columns , with cables supporting the bridge deck....
and a cantilever bridge
Cantilever bridge
A cantilever bridge is a bridge built using cantilevers, structures that project horizontally into space, supported on only one end. For small footbridges, the cantilevers may be simple beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built from...
. No such bridges have been built, nor are there any specific plans, although the method has been considered for several bridges in Norway. It was developed collaboratively by the Norwegian Public Roads Administration
Norwegian Public Roads Administration
The Norwegian Public Roads Administration is a Norwegian government agency responsible for the state and county public roads in the country. This includes planning, construction and operation of the state and county road networks, driver training and licensing, vehicle inspection and subsidies to...
and the civil engineering consulting company Aas-Jakobsen
Aas-Jakobsen
Dr. ing. A. Aas-Jakobsen AS, trading as Aas-Jakobsen, is a civil engineering consultant company specializing in structural engineering. The company is based in Oslo, Norway, and primarily works with bridges, roads, railways, offshore oil and buildings. The company has 250 employees. The company was...
as a means of building bridges with spans between 1000 metre.
The design is based on two separate roadways which are connected by crossbeams. A symphony bridge would have two pylons, which would be circular in hollow cross-section. The center of the bridge would be supported by a central cable (unlike the conventional two side cables of a suspension bridge) connected to the deck via hangers connected to the crossbeams. The cross-beams and hangers are triangular in form. On both sides of the suspension section, the bridge would be built as a cable-stayed bridge with cables from the pylon. The areas closest to the pylons would be constructed with cantilever support. The designers have stated that the bridge would allow for greater wind stability, more drag, faster construction time, lower cost, and increased access for inspections and maintenance.
For the Hålogaland Bridge
Hålogaland Bridge
Hålogaland Bridge is a proposed suspension bridge which would cross Rombaksfjorden in Narvik, Norway. It would be part of European Route E6 and shorten the section from Narvik to Bjerkvik by and from Narvik to Bjørnfjell, along European Route E10 by . The bridge is estimated to cost 2.2 billion...
, which is proposed to have a 1345 metres (4,412.7 ft) long main span, a symphony bridge was considered but was discarded after it was deemed too expensive at a projected cost of 2,380 million Norwegian krone
Norwegian krone
The krone is the currency of Norway and its dependent territories. The plural form is kroner . It is subdivided into 100 øre. The ISO 4217 code is NOK, although the common local abbreviation is kr. The name translates into English as "crown"...
r (NOK), compared to NOK 1,860 for a suspension bridge. The proposed Storfjord Bridge
Storfjord Bridge
The Storfjord Bridge is a proposed suspension bridge that would span Storfjorden in Sunnmøre, Norway. If built, it would be long and have a main span of . This would make it the longest spanned bridge in the world, easily surpassing the Akashi-Kaikyō Bridge, which has a main span of...
could be built as a symphony bridge.