Mono arch
Visual and structural highlight
![](https://www.ssf-ing.de/wp-content/uploads/2024/06/SSF-Monobogen-190822-01-0142-02-comp11-1-1920x1281.jpg)
108
metres of clear span
The mono arch spanning diagonally across the superstructure is truly spectacular.
Challenge: skewed crossing situation
- The arched structure crosses the motorway almost at right angles and the superstructure diagonally, thereby counteracting the skew of the flyover in terms of statics and design
- The regularly arranged cable suspensions enable an extremely slender bridge deck that unfolds its effect regardless of the viewing angle
- The superstructure, which was designed as an oblique-angled girder grid in composite construction, was realised with a clear span of 108.30 m and a slenderness of l/h = 82.0
Site
Between Aschaffenburg and the Biebelried motorway intersection, Germany
Building contractor/client
Free State of Bavaria, represented by the Motorway Directorate of Northern Bavaria
Planning period
2013–2018
Service areas
Object planning, structural engineering
Construction
2018
Construction length
108.30 m
Arch supporting width
53 m
Bridge area
1,256 m²
Flyover of the St2312 motorway over the A3
The gateway to the Spessart is a landmark entirely in the spirit of the competition initiated by the building contractor: the design was to be conceived without a central pillar in order to improve visibility. An arched supporting structure that spans the motorway almost vertically and the bridge deck diagonally over the shortest distance represents the optimal response to the static and design challenges.
![](https://www.ssf-ing.de/wp-content/uploads/2024/06/Monobogen_rohrbrunn_197-1091x727.jpg)
© Stefan Henkel