Inn Bridge Neuötting
The Inn Bridge Neuötting is a structure on the federal motorway 94 and is located north of Neuötting between the Neuötting and Neuötting-Ost junctions. The bridge spans the Inn and its foreland areas and consists of a superstructure for a one-way carriageway, each with two lanes and a hard shoulder.
In the course of the bridge, the highway route has a radius of 1200 m and a transverse gradient of 4.0%. In the elevation there is a rounded tip with a longitudinal inclination of a maximum of 1.1%. The bridge has a maximum height of 11 m above the site and crosses the Inn, which is 100 m wide here, at an angle of 56 gon with a span of 154 m.
The girder bridge is the steel composite road bridge in Germany with the largest span. It was built between 1997 and 2000 as part of the new construction of the federal motorway 94, Munich – Pocking. The construction costs amounted to around 22.2 million euros.
Superstructures
The spans of the five-span, 470 m long superstructures are 95 m - 154 m - 95 m - 68 m - 58 m. There is a box cross-section in the transverse direction. The superstructures are haunched in the longitudinal direction . The construction height above the two river pillars is a maximum of 7.0 m, in the middle of the river and at the bridge ends 3.3 m. The main girders of the two superstructures of the composite steel bridge consist of steel troughs with webs 7.5 m apart below the deck. The box webs have a constant slope of 1:10, which means that the base plate width varies between 7.0 m and 6.3 m due to the variable girder height. The webs are connected to the reinforced concrete deck using headed dowels . The 15 m wide carriageway slabs are not prestressed in the transverse direction and have a maximum thickness of 55 cm with a maximum cantilever length of 4.2 m and a variable cross-sectional height above the main girder webs. In the area of the river pillars, a reinforced concrete floor slab 0.4 m to 1.2 m thick is arranged in the composite over a length of 90 m. Fixed points of the superstructures are the right bank pillars.
Substructures and foundation
The superstructures are supported in each axis on pairs of round piers, with the bank piers being arranged parallel to the Inn, which results in an inclined position in relation to the bridge axis. The bank pillars have a diameter of 3.6 m, the others 2.4 m. All have a full cross-section made of reinforced concrete .
The pillars and abutments are founded on layers of gravel at a depth of 4 to 5 m . For the bank piers, this was done with the help of sheet piling boxes. For this purpose, 16 m long sheet piles were vibrated in. After excavation to the upper edge of the stable subsoil, an underwater concrete block with a thickness of up to 1.8 m was installed. Then the water was pumped out into the sheet pile wall boxes and the actual 2.8 m thick foundation concrete was installed.
Construction work
The steel troughs of each superstructure were delivered in 25 assembly stages with heavy haulage across the road. They had lengths of up to 21 m, heights of up to 3.0 m and weights of up to 65 t. The foreland bridge parts were placed on auxiliary supports by a truck crane and then welded together.
A special feature was the assembly of the 90 m long steel trough segments over the Inn. These had a mass of around 550 t and were first completely assembled on the bank and made floatable. This was followed by setting down in the river, swimming in and lifting in with strand jacks that were attached to the already assembled, cantilevered bridge sections. The reinforced concrete carriageway slab was produced in sections with a formwork carriage using the pilgrimage method.
literature
- Federal Ministry of Transport: bridges on federal roads 2002 . Verkehrblatt-Verlag Dortmund, ISBN 3-935064-15-2 , pp. 21-36.
- Thiemo Langen, Hans Pfisterer, Friedrich Skusa, Jürgen Weber: The largest double- composite road bridge in Germany - the Inn Bridge Neuötting . In: Stahlbau 69 , year 2000, issue 11, pp. 833–841.
Coordinates: 48 ° 15 ′ 16.2 " N , 12 ° 41 ′ 55.6" E