Sophisticated mathematical models as well as solid experimental data are required to assess the safety of
ancient vaults, e.g. in churches. At the University of Wismar an experimental vault (figure 1) was built. Increasingly higher
loads were applied until structural collapse (figure 2). In addition to strain gauges and displacement transducers photogrammetry
was used to measure displacements.
Several hundred affordable printed photogrammetric targets were attached to the vault. Up to 400 photographs
in about 45 minutes were taken form various perspectives using a movable platform. The camera positions are shown as gray
dots in figure 3. For each load level a 3D point cloud was created. Using the advanced analysis algorithms of the Linearis3D
Photogrammetry system the point clouds were matched and visualized in two (figure 4) and three (figure 3) dimensions.
Results and benefits
made it possible to measure the three dimensional displacement of an arbitrary number of points at very low cost and installation
effort. Optical measuring technology contributed substantially to the overall success of the project.
We would like to thank
Prof. Dr.-Ing. Bernd Guericke
and Dr. Rabe as well as the students from Wismar University. More information on the project is available