Features of secondary stress field formation under anthropogenic change in subsoil during underground mineral mining

Abstract

This article reports the studies of the secondary stress field induced by conventional and unconventional mining with nature-like technologies, including honeycomb and frame mine structures. The authors propose a new coefficient of influence for the quantitative assessment of the natural stress field distortion due to mineral mining. Using the data of mine tests, numerical modeling, physical simulation, and calibration of the developed numerical models, the diagrams of influence exerted by the parameters of a mining system on the structure of the secondary stress field are plotted. The highest effect on extension of tensile strain zones belongs to the systems of mining with caving. The weakest impact on enclosing rock mass is exercised by mining with backfilling as compared with the same or similar systems without backfill. The best index Tv = 1 is obtained in case of the new frame mine system recommended for thick and medium-thickness ore bodies in difficult geological conditions. For the honeycomb mine structure designed for extraction of rock salt and polyhalite, the resultant characteristics of the mine stability and mining impact on enclosing rock mass are also positive.