Thermal shock weakening of granite rock under dynamic loading: 3D numerical modeling based on embedded discontinuity finite elements

Abstract

This paper presents a numerical study of thermal shock weakening of granite rock under dynamic loading. A fully 3D numerical scheme based on a com- bined continuum viscodamage-embedded discontinuity model and an explicit scheme to solve the underlying thermomechanical problem was developed and validated through numerical examples. First, the dynamic Brazilian disc test is simulated on intact numerical rock. Then, thermal shock-induced crack- ing due to a moving external heat flux boundary condition, mimicking experi- ments based on plasma jet treatment, is numerically predicted. Finally, numerical Brazilian disc test is conducted on the thermal shocked numerical samples. The predicted and experimental weakening effects are in good agree- ment demonstrating that the present modeling approach has good predictive capabilities. The practical significance of the results is that heat shock pre- treatment can substantially enhance rock gravel and rubble crushing.