Three-hinged arch
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The three- hinged arch is a structure in structural engineering that consists of two partial girders that are hinged to each other at the apex. The joint does not have to be in the middle. The structure is also articulated on the two supports . Such an arrangement is a special case of the frame , which is statically supported.
Frames are used where they not only span a span, but also form a height, enclose a clearance profile. The need to absorb the horizontal thrust normally makes the carrier statically indeterminate. This indeterminacy (restraint) is canceled by a further joint. The carrier between the supports or joints can be different z. B. have polygonal shapes. With three-hinged arches, the supports can be quarter circles, circular pieces or elliptical pieces. The points of articulation are then called fighter and arch vertex . In the quarter points, the beams must have the greatest thickness in order to absorb the bending moments . If the two girders consist of angled straight pieces, a three-hinged frame is created .
With a three-hinged arch as a static system, bridges can be built, but also roofs or halls and the like.
bridges
The Unterspreebrücke in Berlin was built in Germany in 1865 as the first bridge with a three-hinged arch . Only six months after commissioning, there was serious damage because the pillars pushed the too weak abutments away to the side and the apex of the wrought-iron arched construction sank.
The first solid bridges to be erected as three-hinge arch bridges were the Munderking Danube Bridge built by Karl von Leibbrand in 1893 , his Danube Bridge Inzigkofen built in 1895 and the Pont de la Coulouvrenière in Geneva , which opened in 1896, and the King George Bridge over the Zwickau, completed in 1904 Mulde in Wechselburg-Göhren .
The Blue Wonder in Dresden, completed in 1893, is an inverted three-hinged arch bridge .
The Salginatobel Bridge , built in 1929/30 by Robert Maillart in Schiers (Switzerland), is a highlight of the bridge building art of the 20th century. It is an arch bridge with an arch made of box girders under the roadway with three joints and a laid-on, but load-bearing roadway slab.
Postbahnhof Cologne
In the years 1912 to 1914, the Cologne Postbahnhof was built in Cologne-Deutz on an area of 50,000 m² as the third station of this type in Germany with the structure of an articulated arch hall. The deformation energy was alternately distributed in the first hall to a joint at the top of the ridge and in the next hall to two joints on its abutment. The achtschiffige Postverladehalle was still supplemented by a signal box, roundhouse, boiler house and farm buildings. After it was shut down in 2005, it was converted into a "Design Post". The building is included as an important industrial monument in Via Industrialis in Cologne, which was established in 2015 .
literature
- Walther Mann: Lectures on statics and strength theory. Teubner, Stuttgart 1986, ISBN 3-519-05238-5 , pp. 92-93.
- Werner Lorenz : The development of the three-joint system in the 19th century. In: Stahlbau 59th Jg. (1990), H. 1, pp. 1-10.
Remarks
- ↑ A photographic view of this from the online picture book Cologne from 1998 can be found on the Internet at www.bilderbuch-koeln.de
Individual evidence
- ↑ Table in: Concrete Bridges. In: Viktor von Röll (ed.): Encyclopedia of the Railway System . 2nd Edition. Volume 2: Building Design - Brazil . Urban & Schwarzenberg, Berlin / Vienna 1912, p. 271 ff.
- ↑ The “uncomfortable” monuments along Deutz-Mülheimer Strasse. (PDF; approx. 16.6 MB) Archived from the original on February 3, 2014 ; accessed on February 28, 2014 .
- ↑ Modern architecture meets industrial monument. Retrieved February 28, 2014 .