Saale bridge (A 72)
Coordinates: 50 ° 21 ′ 19 ″ N , 11 ° 52 ′ 5 ″ E
 Saale bridge
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| use | Highway bridge | |
| Convicted | Federal motorway 72 | |
| Subjugated | Saale | |
| place | Saalenstein | |
| Building number | B-72 B6a | |
| construction | Arch bridge | |
| overall length | 268 m | |
| width | 28 m | |
| Number of openings | 3 | |
| Longest span | 40 m | |
| Pillar spacing | 58 m to 74 m | |
| Clear width | 45 m to 54 m | |
| height | 39 m | |
| start of building | 1937/1990 | |
| completion | 1940/1993 | |
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| Above sea level | 498 m above sea level NN | |
The Saale bridge spans the Saxon Saale at Hof and crosses the federal highway 72 . It stands at the motorway kilometer 6.5 between the junctions Hof-Nord and Hof / Töpen near the medieval castle "Altes Schloß" - also known as Saalenstein Castle - and was built during the construction of the Vogtland motorway . The foundation stone for the 377 m long structure was laid in 1937, completion and handover followed in 1940. In 1945 the structure was damaged by an explosion. In the following decades, the bridge crossed two lanes of the autobahn, which was interrupted at the inner-German border . As part of closing the gap at the Elstertal Bridge and expanding the motorway, the Saale Bridge was completely rebuilt from October 1990 to May 1993, as the deck had to be widened from 18.3 m to 28 m. Since then, the listed bridge has crossed two lanes and one hard shoulder for each lane. The construction costs amounted to 30 million DM.
construction
Bridge from 1940
As with most of the large bridges on the Vogtland motorway, an arched structure made of natural stone masonry was chosen. The maximum 39 m high bridge has three large arches with pillar spacing of 58 m, 74 m and 62 m and clear widths of 45 m to 54 m. The mean arch width over the Saale is the largest opening in comparison with the other four arched bridges on the BAB 72. The pillars are divided by arched openings. Brick granite blocks of different dimensions were used as the material , which were embedded in backfill concrete inside, which was built in layers as tamped concrete . The granite stones used are Flossenbürger Granite , Mauthausen Granite and Lusatian Granite . The stone blocks were broken in the quarries of the Flossenbürg and Mauthausen concentration camps by concentration camp prisoners. At the western end of the bridge, bastion-like extensions were created on semicircular towers, which were intended to serve as resting places and viewing platforms over the Saale valley.
Bridge from 1993
The renovation in the early 1990s was intended to change the appearance of the bridge as little as possible. A prestressed concrete bridge with nine fields was built into the old structure between the granite side walls. As a superstructure for each directional carriageway, it has a single-cell, constant 2.5 m high pre- stressed concrete box girder, which has a far cantilevered carriageway slab on one side. The construction was carried out with spans of 2 × 17 m, 18 m, 5 × 40 m and 16 m using the incremental launching method . Concrete supports or panes were installed as substructures in the end areas, which either weigh on the existing structure or have their own flat foundations. In addition, new injection piles in the two main pillars support prestressed balance beams with heights of up to 5 m, on which the superstructure is in turn supported. For the installation of the new bridge construction, the old backfill concrete was milled out as far as necessary and statically possible.
literature
- Jürgen Stritzke: Stone bridges . In: Gerhard Mehlhorn (Ed.): Handbook bridges. P. 311, Springer-Verlag, Berlin Heidelberg 2007. ISBN 978-3-540-29659-1
Web links
- Bechert und Partner: Project description (PDF; 228 kB)