Viaduc d'Oléron
Coordinates: 45 ° 51 ′ 11 " N , 1 ° 10 ′ 48" W.
| Viaduc d'Oléron | ||
|---|---|---|
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| use | Road bridge | |
| Convicted | D 26 | |
| Crossing of | Coureau d'Oléron | |
| place | Île d'Oléron | |
| construction | Prestressed concrete - box girder bridge | |
| overall length | 2862 m | |
| width | 10.60 m | |
| Number of openings | 46 | |
| Longest span | 79 m | |
| start of building | 1964 | |
| completion | 1966 | |
| planner | Jean Muller | |
| location | ||
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The Viaduc d'Oléron (also Pont de l'île d'Oléron or just Pont d'Oléron ) connects the French mainland in the Charente-Maritime department with the Île d'Oléron , the second largest island in France (after Corsica ) and the largest island on its Atlantic coast. It was the longest bridge in France when it opened in 1966 until it was relegated to third place by the Pont de Saint-Nazaire in 1975 and the Pont de l'île de Ré in 1988 .
description
The Viaduc d'Oléron begins at Bourcefranc-le-Chapus and leads over a length of 2862 m (3027 m including the access ramps) on 45 pillars over the strait of the tidal Coureau d'Oléron and the oyster farming areas on both sides to one Headland of the Île d'Oléron. It runs partially parallel to one of the dams that lead to the former ferry docks on the edge of the fairway.
The bridge has a 10.60 m wide girder with two lanes for motor vehicles, lanes for bicycles separated by markings and narrow sidewalks on both sides. It is illuminated at night. The bridge also carries water, electricity, and telephone lines to the island.
From a technical point of view, it is a prestressed concrete bridge made up of 46 bridge fields of different lengths on rectangular concrete pillars, including 26 fields with a length of 79 m, the deck slabs of which are supported by single-cell, haunched hollow boxes . The individual field lengths are: 28.75 + 7x39.50 + 59.25 + 26x79.00 + 59.25 + 9x39.50 + 28.75 m.
History, construction process
Since 1875 various proposals have been made to connect the island to the mainland by bridges or tunnels. In 1932 Eugène Freyssinet proposed a prestressed concrete bridge with 28 bridge spans, each 100 m long. But it was not until 1962 that the Campenon Bernard company was commissioned to build the viaduct according to the plans of its chief engineer Jean Muller , which was carried out between May 1964 and June 1966.
The bridge, like Jean Muller's not yet fully completed Pont de Choisy at the time , was cantilevered from precast hollow box girder segments that were produced on land in a temporary precast plant. However, the process contained two major further developments: For the Pont de Choisy, a complete series of the segments required for the cantilever arms had been produced on a long production line using the contact method. This was impossible given the sheer length of the Viaduc d'Oléron. Therefore, only two segments were concreted against each other. After hardening, one was put in the storage area, while the face of the other served as a form of form for the next segment. In this way 860 individual segments were made. Because of the shallow water, the segments could not, as in the Pont de Choisy, with barges transported to the site and are collected using a floating crane. In addition, the constant interruptions caused by the ebb would have delayed the construction process too much. For this reason, a poutre de lancement (launching gantry ) was constructed that stood on a pillar and was long enough to accommodate the segments delivered over the already completed sections of the bridge and then attached to both sides of the pillar to make the cantilever arms To lift their place, where they were, as with the Pont de Choisy, glued with epoxy resin and anchored to the cantilever structure with tendons. If a bridge span was closed in this way and the cantilever arm on the other side of the pier was built in front of the middle of the next bridge opening, the front scaffolding could be moved to the next section. In this way it was possible to build the bridge in just 25 months. This process laid the foundation for a long development in the construction of prestressed concrete bridges in cantilevered construction with prefabricated segments.
Toll or no toll
The bridge was subject to tolls until 1992 . In order to limit the traffic volume, which has meanwhile increased especially due to tourists, an advisory assembly on the island voted in 2014 to introduce a toll or an environmental tax ( écotaxe ) for non-islanders, but this met with resistance. A planned referendum was finally canceled by the Conseil d'État in its function as the highest administrative court.
Web links
- En images: le pont de l'île d'Oléron a 50 ans. Article with numerous photos for the 50th birthday of the bridge, on Sudouest.fr
- Viaduc de l'île d'Oléron on bibi-bourcefranc.fr
Individual evidence
- ↑ a b Bernard Marrey: Les Ponts Modernes; 20 e siècle. Picard éditeur, Paris 1995, ISBN 2-7084-0484-9 , p. 191
- ↑ Oleron viaduct. In: Structurae
- ^ Daniel M. Tassin: Jean M. Muller: Bridge Engineer. In: PCI Journal , March-April 2006 (PDF; 2.1 MB)
- ^ Jean Muller: La conception des ponts. (PDF, 4.7 MB)
- ↑ Île d'Oléron: les élus ont voté pour un pont payant. Article dated December 18, 2014 on Sudouest.fr
- ^ Le projet de référendum sur la gratuité du pont de l'île d'Oléron enterré par le Conseil d'Etat. Article dated September 23, 2016 on Charente Libre.fr