Undermined Rock Failure in Apatite Mines in Khibiny: Topical Problems

The article highlights the urgency of studying processes of deformation, displacement and collapse of undermined strata at rockburst-hazardous deposits of the Khibiny Massif with regard to geomechanical and geodynamic risks. The authors analyze failure specifics in undermined strata under the action of tectonic stresses, which consists in impeding of fracturing due to subhorizontal compression. It is found that as the thickness of ore bodies decreases and their dip angle grows at great depths, the pitch of failure increases. The problems to be solved to continue extraction of apatite–nepheline ore at minimized induced risks and at the preserved economic efficiency are listed.