DAMAGE AND PERMEABILITY EVOLUTION OF GRANITE UNDER IM-PACT LOADS
Blasting vibration is one of the major factors affecting the stability and permeability characteristics of rock structures.Combined with SHPB tests and rock triaxial seepage tests,this paper systematically studies the per-meability evolution of granite under impact loads.Through typical granite samples obtained in the research area,SHPB tests were conducted to study the damage evolution of granite under various impact velocities and times.Then,triaxial seepage tests were conducted to study the permeability evolution of damaged granite under different damage variables and water head differences.Research showed that the damage variable increased with an increase in impact velocity or times.As the damage variable increased,the destruction form of granite underwent three stages in turn:no obvious failure(0＜D≤0.1),edge collapse(0.1＜D≤0.16),and crack penetration failure(D＞0.16).When the water head difference was 0.8 MPa or 1 MPa and the damage variable was less than 0.16,the equivalent permeability coefficient of granite was less than 1.4×10-9 cm·s-1 and increased exponentially and slowly with the increase of the damage variable.When the damage variable was greater than 0.16,the granite was significantly bro-ken and even presented penetrating cracks.The equivalent permeability coefficient increased sharply by orders of magnitude with the increase of the damage variable.This research illustrates the influence of damage and groundwa-ter level on the permeability of granite under blasting vibration and develops the theory of water sealing reliability of underground water-sealed oil storage.
万方数据
维普
