In recent years, in the development of valuable ores of non-ferrous and ferrous metals, development systems with concrete and solidifying backfill are becoming more and more widespread. These systems make it possible in some cases to conduct simultaneous mining of deposits by open-pit and underground methods, to preserve the surface from shearing and collapse, in other cases - to produce advanced excavation of rich ores, to extract the previously left pillars and to work fire-hazardous deposits with relatively small losses and dilution...