Dynamic mechanical properties and fracture damage of non-persistent jointed rock mass with hole

There are a large number of irregular distributed joints in rock mass, which usually show high energy accumulation characteristics, so it is very important to study the crack propagation behaviour of non-persistent joined rock mass containing a hole and to evaluate the strain failure of rock samples caused by stress concentration under different impact loads, which is very important for specifying effective prevention and control measures. In this paper, through laboratory experiments and theoretical derivation, based on DIC digital image correlation technology, the dynamic mechanical properties, damage evolution law and fracture failure characteristics of non-interpenetrated jointed rock mass with hole are studied. The test results show that the existence of the structural plane significantly changes the dynamic mechanical properties of the specimen with different hole. And the dynamic strength and elastic modulus of the specimens increase with the increase of impact load. Peak strain and energy dissipation density show an obvious strain-rate dependence. With the increase of strain rate, the damage degree of the specimens increase continuously. Under the same strain rate, the relationship between the damage degree of the specimens is D-shaped hole specimen>rectangular hole specimen>circular hole specimen. The damage evolution of rock with composite cracks takes into account the energy dissipation and dynamic load effect, and the damage curve increases in an L-shaped manner during the loading process. The structural plane in the sample has obvious strain localization and blocking effect. The stress concentration and plastic zone are mainly located at both ends of the structural plane and the rock bridge area. The tensile strain occurs after the shear strain, and the final failure mode of the rock changes from main shear to mixed tensile shear failure. Considering the maximum hoop stress criterion, the effects of impact load and different hole on the initiation and propagation of