3D FE Modelling of Gravity-driven Rock-deformations for the Estimation of Cavity Effect and Sensitivity

In this paper authors performed 3D finite element modellings in order to analyse gravity driven rock deformations, as well as the effect of the cavity system embodying the equipment, and the sensitivity of planned or existing equipment arrangements. The cavity effect is one of the most important factors influencing the absolute accuracy of geodynamic and gravity-driven (tidal) deformation measurements. Data sets compiled from different observatories should be improved by the estimation of this effect, in order to be conformed and processed together. Results of a method development are presented where the sensitivity and the cavity effect rate are qualitatively and quantitatively characterized by the proposed formulas (parameter fields), based on the output displacement matrix of the 3D FE modelling. As an application example finite element modellings were carried out in order to estimate the influence of the complicated cavity system surrounding the Matyashegy Gravity and Geodynamical Observatory of the MFGI, Budapest.