Alviksbron ( Swedish for ''The Alvik Bridge'') is a

box girder bridge A box girder bridge, or box section bridge, is a bridge in which the main beam (structure), beams comprise girders in the shape of a hollow box. The box girder normally comprises prestressed concrete, structural steel, or a composite ma ...

in central

Stockholm Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

. Stretching over Oxhålssundet, it connects

Stora Essingen Stora Essingen is an island and a district in the Kungsholmen borough in Stockholm, Sweden. It is located adjacent to Lilla Essingen on Lake Mälaren. Both Essingen Islands are mainly residential areas. Stora Essingen is scattered with privat ...

island to the western suburb

Bromma Bromma () is a Boroughs of Stockholm, borough (''stadsdelsområde'') in the western part of Stockholm, Sweden, forming part of the Stockholm Municipality. Bromma is primarily made up of Bromma Parish and Västerled Parish. The fourth largest airpo ...

. Built 1996-1998 by the Nordic Construction Company at a cost of 180 million SEK, it has served the

Tvärbanan Tvärbanan () is a light-rail, light rail line in Stockholm, Sweden, which runs largely in a semicircle south, west and north around central Stockholm - crosswise to the otherwise radial Stockholm Metro, metro and Stockholm commuter rail, commut ...

light rail Light rail (or light rail transit, abbreviated to LRT) is a form of passenger urban rail transit that uses rolling stock derived from tram technology National Conference of the Transportation Research Board while also having some features from ...

line and pedestrians and bicyclists since its inauguration in August 2000. The name is derived from

Alvik Alvik is a residential district in western Stockholm municipality and part of the Bromma borough. See also * 08 Stockholm Human Rights *Alvik metro station Alvik metro station is a station on the Green line of the Stockholm metro, and on th ...

, originally a local

manor house A manor house was historically the main residence of the lord of the manor. The house formed the administrative centre of a manor in the European feudal system; within its great hall were usually held the lord's manorial courts, communal mea ...

built in 1819 and demolished in 1930. The bridge is 400 metres in length with a 140-metre central span and a horizontal clearance of 24 metres. The underside of the bridge tie forms an

arch An arch is a curved vertical structure spanning an open space underneath it. Arches may support the load above them, or they may perform a purely decorative role. As a decorative element, the arch dates back to the 4th millennium BC, but stru ...

intended to make the bridge as slender as possible. The two pillars standing in the water each consist of two thin concrete plates dressed in two-quarters

brick A brick is a type of construction material used to build walls, pavements and other elements in masonry construction. Properly, the term ''brick'' denotes a unit primarily composed of clay. But is now also used informally to denote building un ...

with a common concrete foundation. They are illuminated after dark. The construction is pre-tensioned longitudinally by cables, but non-tensioned across. The topside was stretched as the separate sections were added, while the underside was stretched after all the sections had been cast into a single compact unit. Three years after the inauguration crack formations were discovered in the bridge. The shear fissures in the

rib In vertebrate anatomy, ribs () are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the thoracic cavity, enabling the lungs to expand and thus facilitate breathing by expanding the ...

s had an angle of 25-30° and a length of 0.1-0.3 mm, and were found in greater number on the south side. This is thought to indicate that compressive stress from the longitudinal stressing in combination with heat from the sun caused the problem. The bridge was then reinforced, first temporarily using outside pre-stressing bars, and then permanently using

carbon fibre Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon comp ...

laminate Simulated flight (using image stack created by μCT scanning) through the length of a knitting needle that consists of laminated wooden layers: the layers can be differentiated by the change of direction of the wood's vessels Shattered windshi ...

s in sections with minor fissures, and tie struts in the worst affected sections.

References

External links

flickr - Photo of Alviksbron in winter
(January 2006) Bridges in Stockholm Bridges completed in 1998 Box girder bridges Rail infrastructure in Stockholm County 1998 establishments in Sweden 1990s establishments in Stockholm {{Sweden-bridge-struct-stub