Mining Institute, Ural Branch, Russian Academy of Sciences, Perm, Russia:

S. G. Bychkov, Head of Laboratory, Professor, Doctor of Geologo–Mineralogical Sciences, bsg@mi-perm.ru
A. V. Michurin, Rese archer, Candidate of Engineering Sciences
A. A. Simanov, Researcher, Candidate of Engineering Sciences
V. V. Khokhlova, Junior Researcher, Post-Graduate Student

Long-term exposure to anthropogenic loads associated with the exploitation of mineral deposits has a powerful influence on the natural geological environment. In order to obtain information on the development of negative geotechnical processes caused in rock masses by subsoil exploration, the technique has been developed for high-precision monitoring gravimetric observations, which makes it possible to determine the variation of the field in time. The result of the monitoring observations is the dynamic gravity anomaly defined as the difference between the subsequent and previous values of gravity. Dynamic anomalies are not distorted by the influence of the terrain and do not reflect the non-changing density heterogeneities of the geological section. Since all the invariable components of the gravitational field are present in any pair of observations, the dynamic anomaly reflects only a specific geological or mining process. A geological model of gravimetric monitoring is created, which is a homogeneous geological environment with an isolated area in which changes in rock density occurred. The possible values of gravitational effects are determined depending on the depth of the decompaction zone and its dimensions. The main noiseproducing factors of gravimetric monitoring are considered. The technique for processing and interpreting dynamic gravity anomalies is developed, based on the synthesis of qualitative and quantitative methods of extracting geological information from gravimetric data. The result of the interpretation is the area of propagation and the likely interval of rock decomposition depths. Practical implementation of the technique of high-precision gravimetric monitoring in emergency areas of the Verkhnekamskoye potassium salt deposit has proved its high efficiency. The developed technology allows moving to the next qualitative level of obtaining information on distribution and development of density inhomogeneities in the geological section over time, which significantly increases safety of mining operations.
The study was supported by the Russian Foundation for Basic Research, Projects Nos. 19–45–590011 r_a, 17–45–590302 r_a, 18–35–00299 mol_a).

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