Identification of critical displacements and deformations at subsoil assets based on GNSS observation time series

The article examines approaches to identifying critical displacements and deformations at mining assets using the GNSS observation time series. It is shown that assessing the stability of mining-engineering facilities should not be limited to analyzing absolute displacements of individual stations only, since displacements of the same magnitude may correspond to different stages of the deformation process. Existing approaches to interpretation of the displacement rates, allowable deformations, and hazard levels are reviewed based on an analysis of Russian and international publications, as well as regulatory and methodological documents. Particular attention is given to transition from assessing the kinematics of individual points to analyzing the spatial deformation field. The principal strain axes, dilatation, and maximum shear strain are proposed as informative parameters, which combined analysis makes it possible to identify zones of extension, compression, loosening, compaction, and shear strain concentration. It is shown that universal threshold criteria cannot be directly transferred to all the mining assets and should be refined with regard to the specific engineering-geological conditions, mining regime, characteristics of the monitoring network, and measurement accuracy. It is also noted that reliability of the time-series interpretation largely depends on the quality of data processing, which highlights the relevance of developing domestic high-precision GNSS data processing tools for geomechanical and geodynamic monitoring tasks.