Hochmosel bridge on the B50, Zeltingen-Rachtig

Separated by the Moselle valley for millions of years, the Eifel and Hunsrück mountains have been connected via the 1,704m long Hochmosel bridge since 2019. It is the centrepiece of the 25km long B50 national road that connects the Benelux countries with the Rhine-Main region as part of an international road axis and closes the gap between the A60 and A61 trunk roads. The Hochmosel crossing will lead to a significant reduction in traffic for many Moselle valley communities. The simple beam bridge stands at a height of up to 160m above the valley floor. The long spans of 105m to 210m and the slender, tapered piers also minimise any obstructions to the view of the idyllic Moselle valley.

Hochmosel bridge is a milestone in PORR’s company history
The Berlin branch was awarded the contract for this mega-project in a consortium with SEH Engineering. While SEH was responsible for the 32,000t steel beam construction, PORR erected the up to 150m high piers and the substructures and also carried out the specialist civil engineering for the construction pits and slope stabilisation. When construction started in 2011, the Hochmosel bridge was the largest bridge-building project in Europe.

Extremely high demands on design and construction
The Hochmosel bridge rests on a total of 10 reinforced concrete piers ranging in height from 150m to 20m, which are founded on more than 100 drilled piles up to 50m deep. The special geological conditions on the steep slope meant that these had to be additionally doweled. The reinforced concrete piers have a single-cell rectangular hollow cross-section and wall thicknesses ranging from 30cm to 60cm. When viewed lengthwise, they are conical in shape, and when viewed crosswise, they have a pronounced taper. The single-section superstructure was constructed over 11 spans as a steel beam bridge with an orthotropic deck. The construction varies in height depending on the spans and reaches its maximum height at 7.78m in axis 4.

The shape, height, foundation parameters and mass distribution of this project meant that PORR paid particular attention to the load case of vortex-excited transverse vibrations: Pier models were put through wind tunnel tests, studies were carried out to reduce these forces, measures were developed to avoid them, and the final results were successfully put into practice.