Dynamic Mechanics and Energy Dissipation of Saturated Layered Phyllite

Abstract

This paper is a study of the dynamic mechanics and energy dissipation of saturated layered phyllite. Using the Split-Hopkinson pressure bar system, the mechanical properties and energy dissipation law of the sample during dynamic loading in the test were analyzed. The results show that the weakening effect of water on the phyllite rock body will have a great impact on its mechanical properties, strain rate sensitivity damage mode, and fracture energy dissipation. The values of mechanical parameters such as the modulus of elasticity and compressive strength of the specimens in the test varied with the dip angle of the layer with 0° > 90° > 30° > 60°, and the mechanical parameters of the specimens in the saturated state were smaller than those of the dry specimens. The damage of the sample is mainly in the form of crushing damage at 0° dip angle, shear damage along the laminar surface at 30° and 60°, and destabilization damage of the compression bar at 90° dip angle, with higher fragmentation of the sample in the saturated state. The energy dissipation densities of different inclination samples in the saturated state of schist are greater than those in the dry state, with the highest energy dissipation density in the 0° inclination sample and the lowest in the 90° inclination sample. Both the mean strain rate and compressive strength of the samples showed a multiplicative power relationship with the crushing energy dissipation density of the samples, showing a strong strain rate correlation. These results indicate that the use of rock crushing energy dissipation density can better reflect the strength characteristics of phyllite samples under dynamic loading.