Identification of Natural and Man-Made Decompacted Zones in an Undermined Massif Based on High-Precision Gravimetric Observations

Abstract

This paper presents the results of gravimetric studies carried out at a potash deposit to obtain the information on negative engineering–geological processes in rocks caused by subsoil development. The developed high-precision monitoring gravimetric observation method makes it possible to determine field variations over time. The created physicogeological gravimetric monitoring model is a homogeneous geological medium with an isolated area with a variable rock density. The dynamic gravity anomaly processing and interpreting based on the synthesis of qualitative and quantitative methods for obtaining the geological information from the gravimetric data have been adapted for the gravimetric monitoring purposes. The interpretation resulted in a distribution area and a probable depth interval of rock decompaction, as well as rock density variations, which characterize the decompaction rate. Examples are given in relation to testing the developed technology for dividing the decompressed zones into natural and man-made zones at the Verkhnekamskoe potash deposit in order to improve its operation safety. The monitoring gravimetric observation results can be used to predict the dangerous geological process areas and to control the subsidence of the earth’s surface.