BW 67a of the BAB 73
Coordinates: 50 ° 9 ′ 3 ″ N , 11 ° 1 ′ 45 ″ E
| BW 67a | ||
|---|---|---|
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| Official name | BW 67a 5832760 | |
| use | Road bridge | |
| Convicted | District road LIF 2 | |
| Subjugated | Federal motorway 73 | |
| place | Lichtenfels (Upper Franconia) | |
| construction | Steel composite truss frame bridge |
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| overall length | 101.77 m | |
| width | 11.0 m | |
| Longest span | 90.82 m | |
| Construction height | 2.75 - 6.22 m | |
| height | 19 m | |
| start of building | Fall 2006 | |
| opening | December 2008 | |
| location | ||
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The BW 67a structure of the BAB 73 is a road bridge in Upper Franconia , which leads the district road LIF 2 over the federal motorway 73 and connects the Lichtenfels district of Kösten with the Banz monastery . The bridge structure is in an exposed position above a 19 m deep incision in the slope of the autobahn route, which here leaves the Upper Main Valley, the so-called God's Garden with the landmarks Vierzehnheiligen and Banz Monastery, and is illuminated at night. The motorway axis is crossed at a distance of 67.0 km at an angle of 75.7 gon . The overpass has a 7.0 m wide carriageway for two lanes and 1.0 m wide footpaths on both sides.
construction
The column-free bridge construction consists of a steel tube framework with a composite reinforced concrete deck . The framework is clamped into the massive reinforced concrete abutments. The construction height is 6.22 m at the abutment and 2.75 m in the middle of the bridge.
The lower chord of the framework consists of two tubular profiles, each with an outer diameter of 813 mm, and the upper chord has two round hollow profiles, each with a diameter of 508 mm. The upper chords are connected by horizontal cross struts with a diameter of 244.5 mm, the diagonals between the upper chord and the lower chord vary in their dimensions between 457 mm and 324 mm. The sheet thicknesses are up to 50 mm, the total tonnage of the structural steel is around 310 t. The tubular truss nodes were welded for the first time in German bridge construction without the use of cast steel parts.
The top chords are connected to the reinforced concrete deck using headed bolt dowels . The carriageway slab is 10.35 m wide and with a variable cross-section height above the upper chords a maximum of 55 cm thick, on the cantilever outer sides 23 cm.
The two massive abutments, around 16 m long, are each founded on six bored piles with a diameter of 1.2 m and lengths of up to 18 m.
The structural engineer of the building, SSF Ingenieure GmbH from Munich, was awarded the 3rd prize in the category “Steel components and systems for building” at the steel innovation award in 2009.
Construction work
The construction project was put out to tender in October 2005, and the contract was to be carried out between March and October 2006. The manufacture of the foundation and abutment began in autumn 2006; In the spring of 2007, the work on site was discontinued, as additional complex static calculations and tests with regard to the fatigue strength of the welded pipe framework nodes were deemed necessary. The steel structure could only be delivered in spring 2008. On April 8, 2008, a 40.5 m long middle section of the steel structure with a weight of over 108 t was first lifted onto two pairs of auxiliary supports by a truck crane. After assembly of the edge segments, the entire structure was welded over the auxiliary supports. Then the upper and lower chord tubes were concreted in the abutment. Starting from the middle of the bridge, the reinforced concrete deck was made with a semi- prefabricated slab between the upper chords and with the help of a formwork carriage. The structure was completed in November 2008.
Pictures of the bridge construction site
Reinforcement of the eastern abutment, December 2006
Reinforcement of the eastern abutment, April 2008
Reinforcement of the deck slab and formwork carriage, July 2008
Road slab soffit, July 2008
literature
- Hans-Joachim Casper, Markus Karpa: Wide-span road bridge over the A 73 motorway - construction and static calculation of the tubular framework with welded nodes . In: Proceedings of the 18th Dresden Bridge Construction Symposium, pp. 181–190.
Web links
Individual evidence
- ^ Steel Information Center: Steel Innovation Award 2009 ( Memento from October 1, 2010 in the Internet Archive )