G-tec undertook a microgravimetry survey in the future medical center CHC in Liège. The aim of this survey was to provide important information on the presence of mine shafts.

The density contrasts of soil, rocks and voids cause variations in the gravity field of the earth. Using microgravity the presence of cavities like mine shafts can be detected and mapped.

As the area has been intensively mined in previous centuries many forgotten mine shafts and tunnels are present in the shallow and deep underground, which might cause immediate instabilities or longer term settlements of the medical buildings.

A density map of the underground has been provided to the Client, clearly indicating the locations of the shafts and mine galleries, enabling a more efficient building management and risk assessment of the prestigious project.