Revva V. Advanced fundamentals of rocks deformation and fracture under true triaxial compression

The work is devoted to solution of an important scientific and practical problem of advanced theoretical fundamentals of rocks deformation and fracture under bulk compression with a special attention to true triaxial stress state and structure faults, with the aim to develop methods of rock massif condition prediction and control. Rocks deformation and fracture features under true triaxial compression were defined based on experimental and theoretical investigations depending on stress or strain state modes, straining history, water and/or gas saturation extent, physical or chemical impacts, depth of occurrence, temperature variations, and other influencing factors in a rock mass. Experimental techniques were developed and approved for determination of rock fracture toughness at true triaxial compression and stiffness degree of a loose excavation roof. The prediction method of sandstone outburst hazard based on the effective surface energy has been advanced taking into consideration synchronism in variations of fracture toughness and elastic modulus.