Town hall bridge Lauffen

Lauffen am Neckar

bridge construction Services

Birk Heilmeyer und Frenzel, knippershelbig Architect

Circular hybrid material rib arch bridge with granite segments

Project

The bridge design was developed as part of the competition for the new Rathausbrücke in Lauffen am Neckar. The concept draws inspiration from the arches of the city of Lauffen, reinterpreting them in a modern, hybrid-material rib arch bridge. With only minimal interventions and additions, the existing foundation of the old bridge is retained. The circular bridge structure consists of two prestressed arches made of granite segments, supporting a superstructure of steel and a deck slab of reinforced concrete. This modern natural stone bridge provides a durable construction and blends seamlessly into the historic surroundings between the Rathausinsel and the old town.

The material-hybrid structure combines natural stone, steel, and concrete, each utilized according to its advantageous properties.

bridge construction

The bridge superstructure is designed as a Lohse (Langer) beam: under uniformly distributed loads along the longitudinal axis of the deck, the granite arch functions as a form-active structural system, transferring the vertical loads from the suspended bridge deck. The horizontal components of the arch thrust are closed via the steel deck, which acts as a tension tie. Each arch consists of 20 granite blocks precisely aligned with planar contact surfaces. The heavily loaded carriageway slab and kerbs are constructed as cast-in-place and precast reinforced concrete elements, using stainless steel reinforcement. The choice of materials corresponds to the specific structural demands, ensuring appropriate robustness and durability of each component.