Quantitative characterization of granite failure intensity under dynamic disturbance from energy standpoint

Abstract

Quantitative evaluation of rock dynamic disaster intensity is a challenging and difficult task in the field of earth science. In this article, the dynamic compression tests of granite under different impact velocities are carried out, and the energy evolution characteristics of the dynamic failure process of granite are analyzed. The dynamic fracture characteristics of granite were studied by using computed tomography and section scanning equipment. The results show that the energy dissipation and energy accumulation mechanism of granite under dynamic loading are fundamentally changed with the increase of impact disturbance strength, which leads to the transformation of the failure mode from the tension-type sheet crack under low-speed impact to the complex network crack coupled by tension and shear under high-speed impact. At the same time, the greater the impact velocity, the larger the macroscopic crack density, the more uneven the particle distribution on the fracture section, the greater the roughness, and the higher the rock mass fracture degree. In accordance with the results, the energy distribution ratio is proposed to quantitatively characterize the coupling effect of energy dissipation and energy accumulation in the dynamic failure process of granite and to reflect its dynamic failure intensity. The higher the energy distribution ratio, the stronger the energy coupling effect and the more intense the dynamic failure of the rock mass.

Keywords

• rock dynamic hazards
• granite
• energy evolution characteristics
• fracture characteristics
• energy coupling index
• failure intensity