The paper is a part of a research project aimed at improvement of geophysical (gravimetric) methods. In the project, gravimetric measurements above a cavity of a known size and depth (namely, Březno tunnel near Chomutov) were compared with the results of a gravimetric model.
The model was based on a geotechnical model of the deformation zone around the cavity. In the geotechnical model, the material behaviour is described by a hypoplastic constitutive model for clays.
The paper presents the calibration of this model based on laboratory testing of reconstituted and undisturbed clay samples.