Out-of-service underground water reservoir with masonry walls.
Objective: condition assessment and geometry confirmation before renovations.
The underground water reservoir from the 19th century was decommissioned at the end of the 1970s and is to be converted into a public meeting place in the future. Bridgology was assigned with the non-destructive condition survey of all load-bearing walls as part of the feasibility study for the conversion. The following information was obtained to allow the responsible engineering firm to perform a qualitative condition assessment of the structure:
- Confirmation of the solid construction of the masonry partition walls, as well as of the peripheric gravity walls (no infills within the walls).
- Verification of the integrity of the walls by finding local weak points like leaching of the grout, larger internal cracks, honeycoming or similar.
- Determining the thickness and confirming the construction method of the gravity walls.
The measurement grid was defined in close cooperation with the engineering office. Despite difficult measurement conditions (darkness, high humidity and temperature), the entire reservoir could be measured in one day.
In addition, the investigated area was recorded with a 3D LiDAR scan. This provides an overall view of the reservoir and allows a subsequent “virtual tour”
In addition to the desired information, the 3D scan allowed to obtain an overall view of the moisture penetration from above into the masonry walls: