Instandsetzung einer Geh- und Radwegbrücke durch Austausch der Hänger gegen Seile

Repair of a pedestrian bridge by replacing steel-bar hangers with ropes.

After just a few years of service a large number of cracks were detected on the lower hanger attachments of the pedestrian bridge presented below. The examination and observation of the structure (by long-time measurements and video-monitoring) ultimately led to the identification of the cause of damage, which was the quite regular and wilful excitation of the easily accessible hangers by pedestrians.
The subsequent repair works aimed at increasing the low eigenfrequencies of the hangers into levels, which no longer allowed excitations. To achieve this, the original steelbar hangers, with a diameter of 63 mm, were replaced by locked coil ropes with diameters of 21 and 26 mm. The course of the examinations and the execution of the repair works are described below.