Le Day Viaduct
The Viaduct of Le Day ( French viaduc du Day ) is a railway bridge in Vallorbe in the Jura-Nord vaudois district of the Swiss canton of Vaud . It stands near the hamlet of Le Day and crosses the Orbe , which has been dammed since 1955 by the dam Le barrage du Day, which is 450 m downstream .
The double-track bridge is used by the Paris - Lausanne line of the TGV Lyria , as well as the Lausanne - Vallorbe line of the RER Vaud (Réseau express régional vaudois) and the line from Vallorbe to Le Pont in the Vallée de Joux with the extension to Le Brassus .
Lattice girder bridge (1870)
The bridge, inaugurated in 1870, was originally a lattice girder construction made of wrought iron supported by two stone masonry pillars . Its three unequally wide openings had spans of 36.5 + 56.0 + 23.5 m. It was 5.0 m wide and 59 m above the valley floor. Because of the heavier locomotives and trains, it was strengthened in 1899 and 1900.
Further reinforcement was necessary in the 1920s due to electrification . Extensive investigations revealed a conversion to a massive vault bridge as the cheapest solution.
Conversion to a stone arch bridge (1925)
The Le Day viaduct was therefore rebuilt before the Grandfey Viaduct near Freiburg in the years 1923 to 1925 without interrupting operations and provided with a pedestrian walkway. After the renovation project worked out by the SBB under the direction of Adolf Bühler , the arches were first installed in the existing openings below the iron superstructure, with the apex of the arches reaching just below the lower chords of the lattice girders. The falsework was created by Richard Coray . Then the existing superstructure with the pillars of the future savings arches was supported on them. Finally, the iron structure was demolished in sections and the new superstructure was built.
The total of 161.25 m long bridge was given a main opening with a clear width of 44.00 m. On the large arch there are nine savings arches with a clear width of 4.50 m. The arches in the differently sized side openings naturally have smaller dimensions. The slightly overhanging superstructure is now a total of 8.4 m wide. The arches are made of natural stone, as concrete from the local gravel would not have been able to cope with the high demands and one wanted to avoid the contrast to the existing pillars. Only the parts of the pillars above the walkway, the saving arches and the rest of the superstructure were made of stamped concrete and then clad with natural stone. The walkway in the longitudinal axis of the bridge was made of reinforced concrete. The two large pillars originally stood above the stream bed. Since the Barrage du Day was built , its pedestals have been in the water.
literature
- Swiss railway bridges. Architectural and technical history of the railways in Switzerland, volume 5. Scheidegger & Spiess, Zurich 2013, pp. 34–41.
- Hans Fröhlich: The conversion of the “Viaduc du Day” on the Lausanne – Vallorbe line of the SBB In: Schweizerische Bauzeitung , Volume 89/90, 1927, pp. 227–229 ( doi : 10.5169 / seals-41683 ) and p. 240– 243 ( doi : 10.5169 / seals-41688 )
Web links
Coordinates: 46 ° 43 '20.5 " N , 6 ° 23' 45.5" E ; CH1903: 520289 / 175103