Wooden bridge
The wooden bridge is the oldest type of bridge construction in the history of bridge construction . Starting with the tree trunk that was laid over a ravine or a body of water , the art of wood construction was refined up to the yoke bridges or truss bridges . Since wood has a very low specific weight , it is particularly suitable for building bridges. A distinction is made between covered and uncovered wooden bridges.
history
The Gauls were already familiar with wooden bridges. They had cantilever girders , which consisted of tree trunks piled at right angles on top of each other, backfilled with stones and connected to one another with a wooden superstructure. The design is said to have been used in Savoy until the 18th century . Bridges made of stones and logs are still used to this day in Pakistan , Afghanistan , India and China to cross rivers - mainly in the Himalayas and the adjacent mountains. For this purpose, round timbers are fixed on both banks with piled stones so that their ends protrude towards the middle of the river, which are then connected with laid trunks.
The oldest wooden bridge built by the Romans was the Pons Sublicius . They built both pure wooden bridges as well as bridges with stone pillars and wooden superstructures , which are called stone pillar bridges . See list of Roman wooden and stone pier bridges . The pure wooden bridges were each designed as yoke bridges .
A proposal for a wooden cantilever bridge from the builder Villard de Honnecourt has come down to us from the late Middle Ages . This type of construction does not seem to have spread and was not taken up again until the middle of the 19th century by Gerber and used for iron constructions. During this time, the construction of covered wooden bridges began , in which the supporting structure is protected from the effects of the weather by side walls and roof. Early examples are the Chapel Bridge in Lucerne , built in 1365, or the Ponte Vecchio , built by Andrea Palladio in 1569 - a covered yoke bridge over the Brenta in Bassano del Grappa .
In 1500 a bridge over the Vistula was built in Toruń (Poland) . At that time it was the longest wooden bridge in Poland and one of the longest in Europe.
During the 18th century, Hans Ulrich and Johannes Grubenmann developed some innovations in the construction of covered bridges . In an empirical way, rod polygons were first combined , later arched structures with truss and hanging structures , so that spans of up to sixty meters were achieved. This technique was then also used by the Grubenmann brothers in the construction of wide-span church roofs. The most famous example of their bridge structures is the Schaffhausen Rhine Bridge , which was 120 m long and had only one intermediate pillar. The Neckar Bridge Plochingen , built by Johann Christian Adam Etzel (1743–1801; uncle of Gottlieb Christian Eberhard von Etzel ) in 1778 with a cantilever span of 70 meters, which in 1905 had to give way to the expansion of the station facilities , became known in Europe . The covered wooden bridge Forbach (Northern Black Forest) over the Murg, originally rebuilt in 1955 , originally planned and built by Otto Lindemann from 1778, with its 38 meter span is regionally referred to as the "longest cantilevered, covered and, due to its stability, drivable wooden bridge in Europe".
The railway bridges, which were built in North America in the first half of the 19th century, represent another milestone, especially the wooden trestle bridges , which consist of simple girder bridges with a fine-meshed arrangement of round timber. Ithiel Town , William Howe and Isambard Kingdom Brunel made a name for themselves with wooden railway bridges .
Today, wood is often used in pedestrian bridges, footbridges or other subordinate bridges such as goods way bridges or house driveways, whereas wood is hardly used for larger bridges.
Records
The Vihantasalmi Bridge , opened in 1999, is the longest wooden bridge built for road traffic near Mäntyharju in Finland . It is 168 m long and has a maximum span of 42 m.
The longest covered wooden bridge in Europe is the Bad Säckingen wooden bridge in southern Germany. The Chapel Bridge in Lucerne is one of the most famous . The longest covered wooden bridge in the world is the Hartland Bridge in New Brunswick , Canada , at 390 m .
The longest wooden bridge in Europe is the 225 m long dragon tail bridge, designed as a tensioning ribbon bridge , on the grounds of the New Landscape Ronneburg . The second longest wooden tension band bridge is the 193 m long wooden bridge near Essing over the Main-Danube Canal . In the case of the latter, glulam was unusually used as a tensioning strap.
Examples of wooden bridges
Gallic wooden bridge made of tree trunks
Proposal for a cantilever bridge to Villard de Honnecourt from the 13th century
Carvedras Viaduct , Brunel's wooden bridge
König-Ludwig-Brücke , the only surviving wooden railway bridge in Germany
Vihantasalmi Bridge , the longest road bridge with a wooden suspension frame
Dragon's Tail , longest tension ribbon bridge in Europe
Bridge over the Mill Burn Orkney
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Covered bridges
Chapel Bridge, the second longest covered bridge in Europe
Longest covered bridge in the world
Ströhberne Bruck'n in Styria
Web links
- Jürgen Brunner: The construction of wooden bridges in Switzerland . Supplement to Discussion Report No. 5 of the Eidgenössische Materialprüfungsanstalt at the ETH in Zurich: "SIA-Norms für Holzbauten", Zurich 1925.
- Swiss Timber Bridges - Werner Minder's Swiss timber bridges
literature
- Erwin Fuchs: Bridge Construction: Wooden Bridges , Volume 7, 1957
- Thomas Jahn: Holzbrücken , in: Gerhard Mehlhorn (Ed.), Handbook Bridges: Designing, Constructing, Calculating, Building and Maintaining , (2) 2010, pp. 281–289
- Diethard Steinbrecher: History of timber construction using the example of timber bridge construction in America and Europe ; in: Wolfgang Rug (Hrsg.): Timber construction in the inventory - Historic wooden structures: Berlin, Vienna, Zurich 2018
Individual evidence
- ↑ B. Nebel: Cantilever bridges. Retrieved February 13, 2013 (with picture of a bridge in Nepal).
- ↑ Josef Killer: The works of master builders Grubenmann , doctoral thesis ETHZ , Zurich 1942 - available as PDF (27 MB) on [1] , last accessed on June 30, 2019
- ↑ A. Müller, H. Kolb: Grubenmanns bridges. (PDF; 346 kB) Tec21 , 2009, accessed on February 2, 2013 (The statement in the article that only two Grubenmann bridges still exist is incorrect.).
- ↑ General Encyclopedia of Sciences and Arts ; ed. by SG Verl and JG Gruber, Volume 13, Leipzig 1824, p. 160 (article "Bridges # Wooden Bridges": "Of all peoples, however, the Germans have advanced the building of wooden bridges the most" - The following is a list of outstanding bridge structures in Europe with builder names and details)
- ↑ Figure from 1905 available on [2] , last accessed on June 30, 2019
- ↑ see [3] , last accessed on June 30, 2019
- ↑ Picture gallery ( Memento of the original from March 2, 2009 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. , Fukuoka University
- ↑ "Timber bridge made of half-timbered structure that amazes the world" ( Memento of the original dated December 11, 2007 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. , holzland.de
