Foot- and cycle path bridge Gratwein

The new construction of a pedestrian and cycle bridge over the River Mur in the Austrian province of Styria connects the two towns of Gratwein and Gratkorn and will form part of the existing high-speed cycle path along the river. The 71.4 m long bridge structure will be accessible via three ramps. On the Gratwein side, an additional staircase provides a direct connection to the town center.

From a structural engineering perspective, the bridge structure consists of a continuous girder with a long span of approximately 47.4 m and a short span of approximately 24 m. The superstructure has a 5.28 m wide trough-shaped cross-section with varying heights of the outer girders. The superstructure reaches its maximum height of 3.90 m above the pier and tapers toward the abutments. The minimum girder height is 1.35 m. The superstructure is prestressed longitudinally by prestressing tendons arranged in the lateral main girders, with post-tensioning. The path of the prestressing cables is oriented according to the moment distribution and therefore runs below the deck in the spans and above the deck in the support areas. On the Gratkorn side, the superstructure is monolithically connected to the abutment, while on the opposite side it rests on bridge bearings, one of which is fixed in the longitudinal direction and the other is movable in all directions. The Gratweiner abutment houses a maintenance passageway for inspecting the bearings and connecting the bridge lighting. For drainage, the bridge is designed with a longitudinal superelevation; additionally, it features a transverse slope from the main girders toward the center. In the embankment area on the Gratkorn side, the superstructure is supported by a central pier. For flood protection purposes, the bridge was built higher than the adjacent riverside paths to ensure sufficient freeboard in the event of flooding. The ramp structures required for this were constructed as angled retaining walls using cast-in-place concrete.

The clear width of the bridge and ramps is 4.0 m. For maintenance purposes, the bridges can be driven over with a maintenance vehicle of up to 24 tons. The ramp structures, abutments and pier were completed in April 2019, concreting of the bridge superstructure began in May 2019. The bridge was completed in summer 2019.