Pont d'Aquitaine

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Coordinates: 44 ° 52 ′ 47 "  N , 0 ° 32 ′ 12"  W.

Pont d'Aquitaine
Pont d'Aquitaine
View from the eastern high bank to the west
use Highway bridge
Crossing of Garonne
place Bordeaux
construction Suspension bridge
Longest span 394 m
Clear height 53 m
start of building 1960
completion 1967
location
Pont d'Aquitaine (Nouvelle-Aquitaine)
Pont d'Aquitaine

The Aquitaine Bridge is a road bridge (highway and bike path) on the Garonne in Bordeaux in the region Nouvelle-Aquitaine in France . It is the second longest suspension bridge in France after the Pont de Tancarville . It is shorter than the Emmerich Rhine Bridge , but longer than the Cologne-Rodenkirchen Rhine Bridge , the second longest German suspension bridge.

location

The six-lane bridge is part of the Bordeaux ring road, which, as the A 630 , guides traffic on the A 10 or E 05 from Paris to Spain around the city. It is located in the northeast of the city a little more than a kilometer behind the junction of the A 10 into the A 630 and the N 230.

description

Pont-d'Aquitaine.svg

The suspension bridge has a span of 393.75 m in the main opening and 143 m in the two secondary openings. Their length from anchor block to anchor block is 679.75 m. She uses the hills on the steep right bank of the Garonne to cross the river with a clear height of 53 m. On the flat western bank, a 1014 m long ramp bridge made of prestressed concrete with a gradient of 4.66% was required to overcome the difference in height between the low ground level and the bridge. Together with the 35.40 m or 38 m long anchor blocks, the bridge structure is 1767.15 m long.

In the anchor block on the right bank, the suspension cables are anchored deep in the rock of the high bank. On the left bank, the 35.40 m long, around 20 m wide and more than 50 m high concrete block holds the tensile force of the suspension cables mainly through its weight.

The deck girder consists of a truss construction . It is 20 m wide. There are 2 x 3 lanes on it ; narrow guard rails separate the two directional lanes. There is a subsequently built bike path on both sides.

The 103 m high pylons have pillars made of a reinforced concrete box construction, which taper from 5.3 m in width to 3.3 m in the side view, while from the point of view of the bridge user they are consistently 4 m thick. They are only connected and stiffened by crossbars under the deck girder and below the peaks.

Since they were renewed between 2000 and 2005, the suspension cables have consisted of 61 laid wire ropes , which were pressed together and wrapped airtight with a wire. The individual wires are galvanized to protect against corrosion. The suspension cables are also equipped with a dehumidification system with which dry air is blown into the ropes at the pylon tips, which can then escape in a controlled manner at the lowest points of the ropes. Sensors determine the humidity of the exiting air and control the blowing in.

history

Opened in 1822, the Pont de Pierre was for a long time the only bridge across the Garonne . Due to the increasing traffic, discussions about a second bridge soon began. In 1909 it was finally decided to use a transporter ferry , which was often built at the time. The foundation stone was laid in 1910, and the pillars were built in 1914 when the First World War ended further work. After the war, the suspension ferries were out of fashion. Long discussions in 1939 led to the suggestion that the easiest way would be to demolish the old stone bridge and replace it with a larger one. However, a ministerial decree of 1941 put an end to this idea. After the Second World War , it was soon agreed on the need for another bridge, but not yet on its location. In the meantime, at least the old stone bridge was expanded from two to four lanes in 1953–1954.

In 1954, Jacques Chaban-Delmas , Lord Mayor of Bordeaux, also became Minister for Public Works and shortly afterwards made the decision to build a suspension bridge. The foundation stone was laid on May 20, 1960; on May 6, 1967, the bridge was officially opened.

At that time it was a four-lane bridge with a 1.50 m wide bike path and a 1.10 m wide sidewalk on both sides. The suspension cables each consisted of 37 wire ropes which, in accordance with the doctrine prevailing in France at the time, were not galvanized and were pressed together in hexagonal profiles. From 1979 it became apparent that the corrosion protection used could not prevent individual wire breaks. Over the years, these wire breaks occurred more and more frequently, so that in 1998 it was decided to completely replace the suspension cables and hangers with stronger cables made of galvanized wires. On this occasion, the roadway was also widened to 2 x 3 lanes. To do this, the top crossbar of the pylons and the roadway girders had to be expanded and the new suspension cables completely re-hung further outside. This work was carried out between 2000 and 2005 with ongoing traffic.

See also

literature

  • Marcel Prade: Les grands ponts du monde, première partie. Ponts remarquables d'Europe . Brissaud, Poitiers 1990, ISBN 2-902170-65-3 , p. 230

Web links

Commons : Pont d'Aquitaine  - Collection of images, videos and audio files