... equivalent materials, with a in- fluence radius of output unit in mining chamber of 10 m and depth of 625 m from surface. The model- ing has shown (see Fig. 4) that primary extraction of ore causes formation of a short-term stable cavity but with continuously collapsing walls and roof. The collapsing rock...

..., and in examining methods of excavating deep boreholes and constructing habitable cavities at depth. 1 INTRODUCTION Cosmology, the study of the origins of the universe, is undergoing a golden age of discovery. The basic features of the universe are now apparent (Turner 2007): the universe is 13.7 billion years...