This study concerned the masonry vault of the stream culvert as well as two overlying retaining walls including a cantilevered walkway. Due to the lack of construction plans, the geometry, in particular the thickness of the retaining walls, was to be determined.
The non-destructive measurements showed that the retaining walls have a variable wall thickness. It was also confirmed that the northern wall is unreinforced, while the southern wall has a light reinforcement on the earth side. Regularly occurring cavities behind the wall heads also indicated that the walls were tilting. Finally, apart from the cracks visible to the naked eye, no significant damage could be detected in the masonry of the stream culvert.