Blasbach valley bridge
Coordinates: 50 ° 35 ′ 42 " N , 8 ° 29 ′ 57" E
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Convicted | BAB 45 Sauerland line | |
Crossing of | Blasbach | |
place | near Wetzlar | |
construction | Prestressed concrete - box girder bridge | |
overall length | 405.5 m | |
width | 40.35 m | |
Number of openings | nine | |
Longest span | 46.5 m | |
start of building | 1969 | |
completion | 1971 | |
location | ||
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The Blasbachtalbrücke is one of the numerous viaducts on the Sauerland line - Bundesautobahn 45 . It stands immediately east of the Wetzlarer Kreuz .
In the professional world, the bridge caused a national sensation through a court ruling on cracks in concrete.
description
The bridge crosses the Blasbach and the L3053. The bridge is slightly curved in plan and is 405.5 m long. It has separate structures for each direction of travel, which together are 40.35 m wide. Its nine fields have spans of up to 46.5 m. Its largest pillar is approx. 41 m high. Built between May 1969 to February 1971 bridge is a prestressed concrete - box-girder bridge with two separate superstructures.
It was the first example of an extra-wide motorway bridge in which a feed scaffolding with five support girders was used.
It was strengthened externally in 1999.
As for most of the valley bridges in the Hessian section of the Sauerland line, a replacement with a new six-lane line is planned.
Legal proceedings
Soon after completion, cracks appeared in the concrete of the superstructures, which were the subject of legal proceedings. According to the judicial expert opinion, the course of the cracks had hardly changed between 1972 and 1977. The crack widths were 0.2 mm and rarely exceeded 0.3 mm. Cracks occurred particularly in the area of the coupling joints. The state of the art at that time did not require proof of the fatigue strength of coupling joints.
The LG Wiesbaden dismissed the action. The construction and execution of the bridge would correspond to the agreements made, in particular the official draft and the description of services. It was built in accordance with the recognized rules of technology applicable at the time.
In contrast, the Higher Regional Court Frankfurt am Main, without hearing the expert again, took the view that all cracks were defects, including those less than 0.2 mm wide. The entrepreneur is responsible for ensuring that the work is free of defects and complies with the recognized rules of technology. It does not matter whether the entrepreneur could have recognized the mistake and avoided it. He bears the risk that his work is free of defects, even if the recognized rules of technology have not yet contained any rules relevant to the specific defect.
The judgment caused a sensation in the professional world, on the one hand because it emphasized that a work carried out in accordance with the recognized rules of technology can also be defective, but especially because it represented a legal definition of the defect without going into the technical context or to deal with the judicial expert opinion and its representation of the different types of cracks and their influence on the durability of the bridge.
The discussion about the judgment was only brought to a provisional conclusion in 1982, when the Federal Ministry of Transport in general circular road construction no. 19/1982 on reinforced concrete caps on road bridges only regarded cracks over 0.2 mm wide as a defect. But as recently as 1995, Der Spiegel was able to go into detail on the problem of cracks in an article on prestressed concrete bridges.
Individual evidence
- ↑ a b BAB A 45, replacement construction of a valley bridge, object and structural planning on competitionline.com
- ↑ Hans Wittfoth: Passionate about bridge builders: mosaic stones from the life of an entrepreneur . Verlag Bau und Technik, Düsseldorf 2005, ISBN 3-7640-0457-6 , p. 65, Illus. 48 ( limited preview in Google Book search).
- ↑ A 45 valley bridges - planning sections on Hessen Mobil - road and traffic management
- ^ Gert König, Reinhard Maurer, Tilman Zichner: Prestressed concrete: Probability in bridge construction; Analysis of building data, damage and maintenance costs . Springer-Verlag, Berlin etc. 1986, ISBN 978-3-642-82888-1 , p. 126 ( limited preview in Google Book search).
- ↑ OLG Frankfurt, May 27, 1981 - 17 U 82/80, Blasbachtalbrücken judgment ; NJW 1983, 456; VersR 1983, 545; BauR 1983, 156; the appeal was not accepted by the BGH
- ^ "A certain trust in God." Article of August 21, 1995 in Der Spiegel 34/1995