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