Trimbacherbrücke Competition

The 82m-long Trimbach Bridge over the River Aare connects the town of Olten with the municipality of Trimbach. Recent inspections concluded that the existing reinforced concrete bridge, built in 1913, had reached the end of its service life. As a result, an international competition was launched in 2024 to design a standard-compliant, low-maintenance replacement for pedestrians, cyclists, and vehicles.

Committed to addressing the Climate and Biodiversity Emergency, our proposal focuses on preserving the existing structure and maximising sustainability. The design reuses the main concrete arch, along with its foundations and abutments, integrating it into the new bridge. This approach reduces material consumption, avoids demolition, and reduces construction time.

Using the load bearing capacity of the existing arch, two elegant and slender steel arches, mirroring its curvature, are added on either side. These three elements share a unified design language, giving the bridge its unique and graceful appearance. While the geometry of the new arches matches the original, their slenderness reflects technological advancements since the original arch was built. For pedestrians and cyclists, the new bridge deck prioritises high comfort and safety, while the overall structure is designed to exceed requirements for flood protection, allowing for effective water flow and debris passage.  

The creative re-use of the existing bridge allows for a seamless integration of the historic structure into the new design. By preserving the 1913 concrete arch, the project honours the region's architectural heritage while adapting to modern needs. The design not only showcases sustainable innovation but also maintains a meaningful connection to the past.