Lech bridge A 8
Coordinates: 48 ° 24 ′ 51 ″ N , 10 ° 53 ′ 20 ″ E
| Lech bridge A 8 | ||
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| use | Highway bridge | |
| Crossing of | Lech | |
| place | Augsburg - Gersthofen | |
| construction | Tied arch bridge | |
| overall length | 109 m | |
| width | 41 m | |
| Number of openings | a | |
| Longest span | 109 m | |
| Arrow height | 17.55 m | |
| Construction height | 1.82 m | |
| start of building | 2004 | |
| completion | 2008 | |
| planner | Grassl | |
| location | ||
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The Lechbrücke A 8 is a motorway bridge that leads the six-lane BAB 8 and a footpath and bike path on its south side between Augsburg and Gersthofen over the Lech .
description
On the flat-based abutments , separate superstructures in the form of a tied arch bridge were built for each directional lane . Each superstructure consists of a steel girder grating with a span of 109 m in connection with a reinforced concrete slab and two steel, free-standing arches welded to the girder grid made of airtight welded hollow boxes without wind bracing. The support grid is suspended from the arches with vertical steel bars. The construction height of the deck girder is 1.82 m, the arches have an arrow height of 17.55 m.
The 3 m wide footbridge for the walkway and bike path is mounted on cantilever arms that protrude from the southern girder. On the inside of the two outermost arches, 4 m high, transparent noise barriers were placed. Between the two inner arches there is a 5 m high, opaque and highly absorbent noise barrier. The directional lanes are separated from the bridge structure by concrete protective walls .
A footpath and cycle path leads under the bridge on both sides. At the southern corner of the western abutment, a level was attached from which it can be read that the Lech would reach the lower edge of the girder grid at a water level of 6 m.
Construction process
From November 2004, the steel structure of the southern bridge was first built on the left bank south and parallel to the existing bridge. Then she was pushed across the river on auxiliary piers. Then the superstructure should be completed, i.e. the in-situ concrete slab, the seal, the caps and the road surface should be installed and all other services should be carried out. The bridge was to be connected to the autobahn via provisionally constructed dams and lanes in such a way that all traffic on all four lanes could have passed over the new southern superstructure.
The flood of August 2005 initially thwarted these plans. The provisional eastern foundation was undermined, so that the steel structure, which had already been pushed over the river, sagged by approx. 30 cm on August 23 and threatened to fall into the Lech. As a precaution, therefore, the traffic on the old motorway bridge behind it was blocked, which led to traffic chaos in the region. The foundation was stabilized and the traffic blockage was lifted the following day, but the final repair was not completed until December 2005.
After the traffic could be diverted to the new bridge, the old bridge and its abutments were demolished in the second phase and the new abutments were built for both superstructures. The steel structure of the new northern superstructure was meanwhile installed on the left bank in such a way that it could be brought into its final position over the river by longitudinal displacement and completed there. In addition, the final road connections for both bridges had to be prepared.
In the third phase, the traffic with its four lanes was led over the new northern bridge, the southern bridge was pushed 23 m to the north next to the northern bridge and completed with all connection details. Finally, the final traffic routing was set up and the temporary arrangements were dismantled. The new bridge was opened to traffic in mid-December 2007. Remaining work was done in early 2008.
Until the complete six-lane expansion of the motorway section in 2010, it had only four lanes - like the motorway.
history
The first bridge at this point was built in 1935/1936 as part of the construction of the Munich – Ulm motorway. At first it only had a superstructure for two-lane traffic, which was blown up on April 26, 1945. When it was rebuilt, it also received the second, southern superstructure. In 1982 the reinforced concrete slab was demolished and renewed along with the sealing and covering. It was not wide enough for the six-lane expansion of the autobahn and it was also in such poor condition that it had to be completely rebuilt.
Web links
Individual evidence
- ↑ a b Motorway Directorate South Bavaria: Federal Motorway A 8 West Munich - Ulm, new construction of the Lech Bridge Gersthofen (PDF, 621 kB)
- ^ Grassl Consulting Engineers Construction: BAB A8 West, Lechbrücke Gersthofen
- ↑ Eva Maria Knab: Presses should raise the bridge. In: Augsburger Allgemeine from September 6, 2005
- ↑ New Lech bridge ready for the festival. In: Augsburger Allgemeine from December 13, 2007