Viaur viaduct
Coordinates: 44 ° 7 ′ 25 ″ N , 2 ° 19 ′ 53 ″ E
| Viaur viaduct | ||
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| Official name | Viaduc du Viaur | |
| use | railroad | |
| Crossing of | Gorges du Viaur | |
| place | Tauriac-de-Naucelle , Tanus | |
| construction | Combination of three-hinged arch bridge in the middle section with cantilever bridge with suspension girders at the beginning and end of the truss bridge |
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| overall length | 460 m | |
| Longest span | 220 m | |
| height | 116 m | |
| building-costs | 275,000 gold francs | |
| start of building | 1895 | |
| completion | 1902 | |
| opening | October 5, 1902 | |
| planner | Paul-Joseph Bodin | |
| location | ||
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| Structure | ||
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The Viaur Viaduct ( French Viaduc du Viaur ) is a single-lane steel railway bridge that spans the Viaur valley near Tanus in France . The viaduct was designed by Paul-Joseph Bodin towards the end of the 19th century and built under his direction. The bridge is part of the Rodez - Carmaux railway line .
location
The Viaur viaduct is located on the territory of the municipalities of Tauriac-de-Naucelle and Tanus. Since the Viaur is also the departmental border here, the viaduct also bridges the gap between the Aveyron and Tarn departments .
history
The first railway line in this region was a connection from Carmaux to Albi, which the owners of the coal mines in Carmaux, the de Solages family, had built. It went into operation in 1857.
Even at the beginning of the Second Empire , state plans existed to build a railway line from Toulouse via Albi and Carmaux to Rodez. However, the undertaking failed because of the impassable gorge of the Viaur. It was not until the end of the 19th century that metal construction in bridge construction had developed to such an extent that the realization of structures such as the Viaur Viaduct could be considered.
The project was put out to tender in 1887. At this point in time, the planning still corresponded to a conventional masonry design . Only in the course of the project planning phase did the resulting steel structures influence the engineers' designs . In addition to five other engineers, Gustave Eiffel and Paul-Joseph Bodin took part in the tender. Amazingly, Eiffel did not win the contract, although it had extensive experience with the Ponte Maria Pia in Portugal, the Garabit Viaduct and the Eiffel Tower , which is currently under construction . Bodin's proposal was chosen because of its technical innovation. The bridge was built by the Société de construction des Batignolles (today Spie Batignolles ), for which Bodin worked.
Construction work began with the laying of the foundation stone on May 9, 1895 and lasted seven years. On October 5, 1902, the Viaur Viaduct was inaugurated by the civil engineering minister Émile Maruéjouls .
The opening of this railway connection led to an economic boom in the entire region thanks to the cheap transport options for heavy goods.
The French painter Henri-Marcel Magne was most likely inspired by the Viaur viaduct for his painting Construction d'un viaduc .
In 1984 the Viaur Viaduct was added to the inventory of the Monuments historiques .
technical description
The bridge includes the following features:
- It is a riveted steel bridge .
- The middle field is a three-hinged arch with an attached framework , the top belt of which carries the roadway.
- The framework over each half of the three-hinged arch continues to the outside as a cantilever . At the respective end of the beam and on the abutment that follows further out , a relatively short suspension beam is articulated. The bridge is therefore partly a cantilever bridge with a Gerber beam .
In the literature, the bridge is referred to as both a cantilever bridge and a three-hinged arch bridge .
Of the total length of 460 m, 410 m are accounted for by the steel structure and 50 m by the two brick abutments (short multi-arched stone bridges). The three-hinged arch has a span of 220 m. In the direction of the abutments, the supporting structure protrudes 69.6 m each, the suspension beams are each 25.4 m long. The apex of the arch is 116 m above the Viaur and has an arrow height of 54.7 m. The bridge is 5.9 m wide at the top. It widens sharply downwards and reaches a width of 33.4 m at the bearings.
The vertex joint is loaded by vertical and horizontal forces. Depending on the load, the radial force in the 200 mm thick hinge pin is 1500 to 4200 kN.
The approximately 3,500 tons of steel parts are held together by a million hand-set rivets. These rivets alone weigh 160 tons. With 80 tons of paint, the bridge is protected against rust . The masonry of the upward and the abutment consists of approximately 4000 cubic meters of stones.
The outer arch fields were mounted on a falsework. From there, the middle arch parts were made using cantilever arches .
Meaning today
The Viaur viaduct is still the largest steel bridge in France and has lost none of its fascination with its filigree construction.
The Rodez-Albi rail connection is now of minor importance. However, several trains still run daily on this route (2015).
The northern end of the bridge can be reached from Saint-Martial and Malphettes via the D 574, the southern end can be reached via Tanus or Laval. The old road N 2088, which crosses the Viaur in the valley floor, offers a very good view; the light is particularly good in the evening.
In this region too, traffic has shifted significantly to the road. The old road layout was no longer able to cope with this volume of traffic. For this reason, the road bridge Pont de Tanus was opened in 1998 , which spans the gorge 1.7 kilometers west of the railway viaduct. This new road bridge is also called the Viaur Viaduct, which can lead to confusion. It was built almost a century after the railway viaduct through the Spie Batignolles .
photos
Road sign
Paul-Joseph Bodin
Memorial plaque
Northern support
Viaur viaduct
evening atmosphere
Early morning mist
Structure in the fog
literature
- Richard J. Dietrich: Fascination Bridges . 2nd Edition. Callwey, Munich 2001, ISBN 3-7667-1511-9 , pp. 186-193 .
- Antoine Picon (sous la direction d '): L'art de l'ingénieur - constructeur, entrepreneur, inventeur . 1st edition. Éditions du Center national d'Art et de Culture Georges Pompidou, Paris 1997, ISBN 2-85850-911-5 , p. 85,537 .
Remarks
- ↑ In different sources amounts between 275,000 and 3,026,994 gold francs are mentioned.
- ↑ Memorial plaque on the northern support
- ↑ If one looks at the two parts of the truss structures that protrude inwards and towards the slope and that are articulated on the foundations in the slope, appearing like thickened T- pillars as reciprocal cantilevers, the bridge can also be understood as a cantilever bridge as a whole.
Individual evidence
- ↑ Engraving after the painting by Henri-Marcel Magne
- ↑ Klaus Stiglat: bridges on the way . John Wiley & Sons, 1997, ISBN 3-433-01299-7 , pp. 108–110 ( Chapter 3.17 in Google Book Search). The author uses both terms and an additional cantilever arch bridge next to each other.
- ↑ a b c Klaus Stiglat
Web links
- Viaur viaduct. In: Structurae
- Viaur Railway Bridge on HighestBridges.com (English)
- Beginning of industrialization in the Carmaux area ( Memento from February 13, 2013 in the web archive archive.today ) (French)