Melan Arch Bridge

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The Melanbogenbrücke (also Siegbrücke ) is a road bridge over the Sieg between Sankt Augustin-Menden and Troisdorf-Friedrich-Wilhelms-Hütte in the Rhein-Sieg district in North Rhine-Westphalia. The L 143, here called Siegstrasse , runs over it . The historical bridge construction, which also includes approach bridges , connects the neighboring towns and industrial areas with each other as well as with the national transport network. The bridge is an important monument of German engineering. Due to stability deficiencies, a demolition and the new building at the same location are planned.

West side, 2011
The structure with the river bridge and the foreland bridge on the Sankt Augustinian side

history

The concrete arch bridge was built using the Melan construction method, which goes back to a patent from the Austrian civil engineer Josef Melan . This quick construction method was chosen in order to avoid obstructions caused by autumn and winter floods. The bridge was built in the course of planning to bypass the through traffic for Siegburg. Until then, a ferry operated on the spot. Construction began in 1928. The concrete work was carried out by the construction company Hüser & Cie. carried out in Oberkassel ; the steel structure gave the work Sterkrade the Gutehoffnungshütte .

Inaccuracies in drawing, failure to take into account the weight of the formwork and the uneven filling of the concrete in the formwork led to the construction collapsing during the concrete work on December 8, 1928. A construction worker was killed.

The bridge construction, started again in 1929, was successfully completed in the same year. The bridge was partially destroyed in World War II. In 1949 it was re-inaugurated after it had been rebuilt true to the original.

In 2007 it was placed under monument protection. In the same year, overuse defects were found on the hangers of the arch. Provisional reinforcements (additional steel brackets, known as "suspenders") were installed to ensure that the bridge could continue to be used temporarily by cars and limited heavy traffic. It was closed to heavy traffic over 14 tons. Until the closure, around 700 trucks to and from the industrial areas Josef-Kitz-Straße and Mendener Straße in Troisdorf crossed the Sieg every day. Suppliers to the Klöckner-Mannstaedt works and the adjacent waste disposal companies RSAG, Remondis and Suez were particularly affected .

construction

The bridge spans the approximately 60 meter wide river bed of the Sieg and the flood areas adjoining it on both sides . The bridge structure has a total length of 265 meters and a width of 10.8 meters. It consists of three sections: six flood or foreland arches in the high water area on the Menden side with spans of 20 to 25 meters, the river bridge over the Sieg with the Melan arch with 60 meters span, and a flood arch on the Troisdorf side with 20 meters Span. The arch of the river bridge is stretched above the roadway, a steel-concrete composite structure reinforced with profiled steel, which is connected to it with concrete hangers. Only a few melan arch bridges were built according to this principle, another is located in the former Arnau on the Upper Elbe . The flood arches are designed as three-hinged arches with a deck slab.

New building

Due to technical difficulties in renovating the melan arch construction, authorities and politicians decided to replace the old bridge with a new building, presumably in the form of a tied arch bridge , i.e. with a visually similar construction. Despite being a listed building, a demolition permit was granted in 2012. An alternative that provided for preservation as a pedestrian and bicycle bridge with the simultaneous construction of a road bridge was discarded for reasons of cost. The start of new construction was initially planned for 2019 [out of date] , but this turned out to be too optimistic and ultimately untenable. Currently (as of April 2020) it is assumed that the demolition of the old bridge can begin at the end of 2021 / beginning of 2022 at the earliest. The demolition alone will most likely take four to six months. During the construction period of around two years, the crossing will be completely closed and traffic will be directed over the Siegbrücke of the B 56 .

See also

Web links

Commons : Melanbogenbrücke  - collection of images, videos and audio files

Individual evidence

  1. ↑ Hikes and bike tours in the countryside C Tour 2: “Kleine Ostrunde” on sankt-augustin.de
  2. ↑ Martina world: ailing bridge over the victory. A memorial is waiting to be demolished. In: Bonner General-Anzeiger of March 21, 2017
  3. ↑ Michael Lehnberg: Melanbogenbrücke over the Sieg is to be rebuilt. In: Bonner General-Anzeiger from January 21, 2013
  4. ↑ http://www.klu-und-du.de/fileadmin/redaktion/bilder/troisdorf/huette/fahrradrallye/81_eisenbahnbruecke_ueber_die_sieg.jpg
  5. ↑ http://www.rheinische-industriekultur.de/objekte/Menden/Siegbruecke/siegbruecke.html
  6. ^ Rhein-Sieg-Kreis (Ed.): Yearbook of the Rhein-Sieg-Kreis. Rheinland-Verlag, Cologne 2008.
  7. ↑ Claus Goralski, Holger Eggemann: Reinforcement of the Melan bridge over the victory near St. Augustin. In: Concrete and reinforced concrete construction , issue 1/2008, p. 49 f.
  8. ^ Regional news archive 2006 , neunkirchen-seelscheid.info
  9. ↑ The Melanbogenbrücke will not be demolished before the end of 2021 in General-Anzeiger Bonn on April 13, 2020, accessed on April 13, 2020
  10. ↑ Andreas Helfer: Ailing building. New bridge at Menden over the Sieg in sight. In: Rhein-Sieg Rundschau from December 13, 2016
  11. ^ Dieter Krantz: Menden / Troisdorf. Two years detour for cars and cyclists due to the construction of the new Melanbogen Bridge. In: Rhein-Sieg Rundschau from April 7, 2017

Coordinates: 50 ° 47 '54.3 "  N , 7 ° 9' 59.5"  E