Useful minerals with hydraulic mining with holes is under review here. New variational method of calculation of parameters of working out deposits on continent and under sea-bottom on the shelf is adduced. New design procedure for critical roof deflection of rock layers and tensile stress take into consideration their slipping and bending of cross sections in deformation of layers, which allow to determine functional safe parameters of working out technology.
Development of coal and ore mining in XXI century is bound up with application of new economic and ecologically good technologies, capable to apply mining without presence of people in stoping face instead of expensive underground method of mining, Method of hydraulic mining with holes (SGD) is one of such technologies, which may be successfully applied in mining of both coal deposits and ore deposits and placers, for example, titanium magnetite sands on the shelf under sea-bottom. At present business-plans for extraction of coal with hydraulic mining with holes in the mines of Partizansk and "Lipovetskoye" have been working out by officials of "DALVOSTNIIugol", "Geotechnology", Moscow and FESTU (Far Eastern State Technical University). Test mine "Vostotchniy-3" was established there. The very mlportant problem here is the choice of rational width of the chamber (or belt), excluding critical roof deflection. Caving of the roof may result in obstruction for hydraulic giant and put the hole out of action. The existing methods of calculation (Borisov and Kaidalov 1977; Kaidalov, and Labazin 1977) are complicated and it is difficult to use them by ordinary engineer in computer. The The simplified methods of calculation for critical settling of rock layer and tensile stress on lower surface of layer with The new ecologically good technology of extraction of solid consideration of bending of cross sections in deformation of rock layers is given below.