Fechingen Valley Bridge on the A6 near Saarbrücken
Together with DKFS Architects, London, Schüssler-Plan won the bidding competition for the new Fechingen valley bridge on the A6. The 424 m long steel composite bridge is of outstanding urban significance for the Saarland. It is situated in an exposed location and, as a defining element in the landscape, acts as the gateway to the Saarland and represents an image of the state capital of Saarbrücken. The alternating sequence of piers and open spaces resulting from the logic of engineering principles also harmoniously divides the valley when viewed from afar.
The span widths of the 6-span bridge are 55m – 74m – 83m – 83m – 74m – 55m. The locations of the piers, in addition to taking into account the specified boundary conditions of the roads running under the bridge, are chosen to preserve maximum transparency in the valley and achieve a statically balanced span ratio. The reinforced concrete piers of axes 20 to 60 are monolithically connected to the superstructure. The semi-integral design combines the following advantages in a synergetic effect:
- Maintenance-free, robust connection of the piers due to the absence of bearings
- Attractive bridge soffit design (no bearing joints)
- Slender columns
- Low servicing and maintenance costs
The monolithic attachment of the piers to the steel box girder is achieved by headed shear studs and by passing the reinforcement through openings and anchoring them in the in-situ concrete cross frame inside the steel box girder. Due to the sophisticated construction phases, the piers are attached integrally to the superstructure after the conventional insertion of the superstructure. The slender columns and unobtrusive superstructure allow the flow of cold air in the valley area. The structure has practically no collision effects on animals. The structure and the chosen method of erection meet all the requirements of the environmental impact study in the best possible way.
In addition to its economical construction method, the incremental launching method also provides an erection method that involves minimum disruption and land use in the valley during the construction period. No auxiliary supports or special auxiliary constructions are required. As the superstructure is fabricated in a nearby construction yard, the transport of materials and the logistics for the construction of the bridge can mainly take place along the A 6 autobahn.
In addition to the desired appearance, the innovative, semi-integral construction method also makes a decisive contribution to a durable and robust supporting structure.