Mikko Räsänen (UEF) operating the EIT-measurement system in the St. Gallen field site.

UEF researchers, Associate Professor Aku Seppänen and PhD student Mikko Räsänen, visited St. Gallen field site on November 15th – 22nd 2019 and tested experimentally the novel structural health monitoring (SHM) techniques that UEF has developed in S4CE project. The visit was hosted by Thomas Bloch, project manager from municipal utilities and well operator, St. Galler Stadtwerke.

Thomas Bloch (St. Galler Stadtwerke) casting concrete

The research is conducted in collaboration with Associate Professor Mohammad Pour-Ghaz from North Carolina State University.

The new SHM techniques are based on electrical impedance tomography (EIT), which uses sets of current injections and potential measurement from the target’s surface to image the two- or three-dimensionally distributed electrical conductivity of the target. In the St. Gallen field site, the EIT-based SHM techniques are tested in the cellar of a temporarily shut-in geothermal well.

Fig 5. A sensing skin on the cellar wall.

The aim of the experiments is to demonstrate the feasibility of the techniques to detect damages in the well casing structures as well as in the walls of the well cellar.