Pont du Veurdre

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Coordinates: 46 ° 45 ′ 29 ″  N , 3 ° 2 ′ 57 ″  E

Pont du Veurdre
use Road bridge D 978A
Crossing of Allier
place Le Veurdre
construction Reinforced concrete arch bridge
overall length 227 m
Number of openings 3
Longest span 72 m
Arrow ratio 1/14 u. 1/15
start of building 1909
completion 1910
Status Blasted in 1944
New building 1946–1948
planner Eugène Freyssinet
location
Pont du Veurdre (France)
Pont du Veurdre

The Pont du Veurdre is a road bridge over the Allier in the town of Le Veurdre in Allier in the French region of Auvergne Rhône-Alpes .

history

First bridges

At the place halfway between Moulins and Nevers , the first bridge was probably built as early as the 15th century.

In 1834, Marc Seguin built a single-lane suspension bridge with three openings.

Pont du Veurdre by Freyssinet

Between 1909 and 1910 the bridge, known to experts as the Pont du Veurdre by Eugène Freyssinet , was built according to his plans by the company F. Mercier from Moulins.

In his first position as an engineer in the local road administration in Moulins, the young Freyssinet had built various small bridges since 1905 for the mayors of the municipalities of the Allier department, who had little money at their disposal and were happy about his support. Freyssinet did not have to present his plans to anyone for approval and was able to generously disregard building regulations that were hardly applicable to concrete bridges.

In the small, 26 m wide bridge of Prairéal-sur-Besbre (Allier) on Besbre ( ) he spent in 1907 for the first time often repeated later method in which falsework not be solved by lowering of the finished bridge arch, but rather the two sheet halves to be pushed apart by hydraulic presses attached to the vertex and thus lifted off the falsework ( French décintrement par vérins ). World icon

The construction of a new bridge with three openings over the Allier, on the other hand, was a large project that was announced by the Conseil départemental in 1907 as a stone arch bridge. A proposal by a young engineer that deviated from the tender would have been futile. By chance, François Mercier, a building contractor working in bridge construction, saw a design for the Pont Boutiron at Freyssinet , which he had made out of his own interest. Mercier was impressed by the design and offered the département council not only the Pont du Veurdre, but also the subsequent similar projects Pont Boutiron and Pont de Châtel-de-Neuvre based on the Freyssinet system at the estimated price of a stone arch bridge determined by the authorities to build. The council could not withstand this and gave Mercier and Freyssinet appropriate orders.

Before the actual start of construction, Freyssinet had a test arch constructed with a 50 m span , an arrow height of 2 m and a width of 2.50 m, which decreased to 1.50 m at the apex. In order to save costs, only small abutments were made, which were connected by a concrete rod with prestressed wires - the first forerunner of prestressed concrete .

The Pont du Veurdre had three openings with spans of 67 + 72 + 67 m, which were spanned by three-hinged arches with an arrow ratio of 1/14 or 1/15, which was extremely flat for concrete bridges at that time. The arch thickness was 50 cm at the abutment and 19 cm at the top. Truss-like triangular bracings on the arches served as stands for the also very thin deck.

With this bridge, too, Freyssinet used his method of relieving the falsework by pushing the arch halves apart before removing it. After the bridge was opened, in the spring of 1911, he found that the apex of the arches had sunk by up to 13 cm. At that time, the creeping and shrinking of concrete were still largely unknown processes. However, Freyssinet immediately recognized the effects of these processes on his bridge. In order to avert the impending collapse, he literally had the vertex joints removed in a nightly operation and the halves of the arch pressed apart again with hydraulic presses until they had reached the correct height again. The openings were filled with concrete. The bridge was saved - and Freyssinet began to deal extensively with the creep and shrinkage of concrete.

The Pont du Veurdre was blown up by the Resistance during World War II in September 1944 to stop the retreat of the German army.

New building (1948)

Between 1946 and 1948 the destroyed bridge was replaced by a Gerber girder bridge with haunched hollow boxes made of concrete with three openings.

literature

  • David Fernández-Ordóñez: Eugène Freyssinet: “I was born a builder” . In: Manfred Curbach (Ed.): 28th Dresden Bridge Construction Symposium ; 12./13. March 2018 . Technical University of Dresden, Dresden 2018, ISBN 978-3-86780-544-5 , p. 101–126 (In PDF: pp. 103–128) ( tu-dresden.de [PDF; 23.6 MB ]). (English)

Web links

Individual evidence

  1. ↑ Pont sur l'Allier à Le Veurdre - 1834 on Art-et-Histoire.com
  2. ↑ a b Pont du Veurdre on geodazner.blogspot.de (French)
  3. ↑ a b c Yves Guyon: l'homme et son œuvre. In: L'Ingénieur – Constructeur, Revue technique mensuelle n ° 134, March – April 1969; Special edition on Freyssinet and Prestressed Concrete ( digitalisat PDF; 17.6 MB), p. 89 (94 in PDF), in particular p. 94 (99)
  4. ↑ Freyssinet later described the first French rules on reinforced concrete from 1906 as completely unusable (cf. la leçon de Freyssinet - Un coup de griffe In: L'Ingénieur-Constructeur, Revue technique mensuelle n ° 134, March-April 1969; special edition about Freyssinet and Prestressed Concrete ( digitalisat PDF; 17.6 MB), p. 4 (7 in PDF))
    This refers to the Circulaire du 20 octobre 1906, concernant les instructions relatives à l'emploi du béton armé . In: La Houille Blanche , 1907, p. 148; on www.shf-lhb.org
  5. ↑ P. Lebelle: Ouvrages d'art, Ouvrages maritimes. In: L'Ingénieur-Constructeur, Revue technique mensuelle n ° 134, March-April 1969; Special edition on Freyssinet and prestressed concrete ( digitalisat PDF; 17.6 MB), p. 19 (22 in PDF)
  6. ↑ Les principales inventions d'Eugène Freyssinet on the website of the Association Eugène Freyssinet
  7. ↑ a b Bernard Marrey: Les Ponts Modernes; 20 e siècle. Picard éditeur, Paris 1995, ISBN 2-7084-0484-9 , p. 49
  8. ↑ Bernard Marrey: Les Ponts Modern; 20 e siècle. Picard éditeur, Paris 1995, ISBN 2-7084-0484-9 , p. 50
  9. ↑ Bernard Marrey: Les Ponts Modern; 20 e siècle. Picard éditeur, Paris 1995, ISBN 2-7084-0484-9 , p. 51
  10. ↑ Le Veurdre - Acceuil ( Memento of the original dated August 16, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. on the municipality's website @1@ 2Template: Webachiv / IABot / www.leveurdre.fr
  11. ↑ Allier Bridge Le Veurdre. In: Structurae