Weißenbrunn am Forst valley bridge

Weißenbrunn am Forst valley bridge
	May 2018
Official name	Weißenbrunn aF viaduct
Convicted	; High- speed line from Nuremberg to Erfurt
construction	Prestressed concrete box ; girder bridge
overall length	614 m
width	14.30 m
Longest span	76 m
Construction height	4.0 m
height	40 m
start of building	2008
completion	2012
	location

50.198333333333 10.998888888889Coordinates: 50 ° 11 ′ 54 ″ N , 10 ° 59 ′ 56 ″ E

The Weißenbrunn am Forst valley bridge , also referred to in the literature as the "Weißenbrunn valley bridge", is a railway overpass on the new Ebensfeld – Erfurt line near Weißenbrunn am Forst in the Coburg district . With a length of 614 m, it spans the valley of the Weißenbrunn Bach between the route kilometers 98.263 and 98.877 at a height of around 40 m.

The in plan view with a radius of 3570 m has curved structure with range expansion on the western side of 2.0 m and 4.0 m high noise protection wall and a slab track obtained with 4.7 m of track pitch.

The bridge was tendered for a design speed of 300 km / h. A structure that can be driven on at 280 km / h (3570 m radius and 135 mm cant ) was built. To the north, the Niederfüllbach connecting curve connects the Coburg train station to the new line.

Building

The bridge construction consists of a chain of eight single-span girders , a frame bridge and two further single-span girders. The cross-sectional shape is a single-cell reinforced concrete hollow box, prestressed in the longitudinal direction, with inclined webs and a standard construction height of 4.0 m, in the area of the frame up to 5.0 m. The deck slab is also prestressed in the transverse direction.

The structure has 43 m, 7 × 44 m, (50 m, 76 m, 50 m), 44 m and 43 m spans, with a superstructure width of 14.30 m. The longest span over the Weißenbrunner Bach with 76 m is spanned by a frame structure, the stems of which are V-shaped (as with the Main Valley Bridge in Gemünden ). The superstructure is monolithically connected to the posts . This reduces the effective span to 50 m. The frame posts have a hollow cross-section with a foot dimension of 2.80 m × 5.30 m with a constant wall thickness of 0.4 m. They rest on concrete joints arranged below the site . The associated foundations are built up to 30 m deep with piles.

The ten reinforced concrete piers have a cross-section width of 6.0 m at the pier head and are 3.5 m thick there, as the arrangement of four bearings is necessary for the single-span girders . Rail extensions are not available, but there are compensation plates for the expansion joints above the pillars.

The structure was put out to tender across Europe at the end of January 2007 and awarded in August. Construction work began in April 2008. The structure should be completed on schedule in 2011. The rest of the work dragged on until 2012. The excavated earth and the required concrete were estimated at around 17,500 cubic meters, the investment costs at around € 11 million. At the end of October 2010, the last section of the superstructure was concreted on an advancing scaffold.

Concrete joint

encased concrete joint in the final state

Concrete joint

A special feature of the structure are the concrete joints under the two frame supports. The upper joint block has dimensions of 9.20 m and 4.40 m, the unreinforced joint neck below is 8.0 m long and 0.4 m wide, which corresponds to approximately one twelfth of the cross-sectional area of the subsequent joint heads.

Before these components were manufactured, a 1: 1 scale test specimen had to be reinforced and concreted in one pour in order to minimize the risk of inadequate quality of the joint neck, which is difficult to access due to the formwork, and the highly reinforced joint heads. The test specimen had a height of about 2.5 m, a width of 4.2 m and a length of 9.3 m. The test specimen was sawn to test the built-in concrete for defects.