Experimental study on crushing dissipated energy of deep granite under triaxial geostress condition
The dynamic impact test is one of the most effective as well as reliable scientific approaches to obtain dynamic strength parameters and crushing dissipated energy factors under different strain rates. Currently, most such SHPB tests are limited to being uniaxial or conducted at lower confining pressures (smaller than 20 MPa). Thus they do not meet the practical demands of deep underground design-analyses under desirable high geostresses. In this paper, adopting self-developed high triaxial pressure device, a serious of modified SHPB impact tests on deep granite from Sanshandao gold mine were conducted under considerably high triaxial confining pressure conditions. Considering real geostresses in deep granite within −2000 m depth, different confining pressures (10 MPa, 20 MPa, 30 MPa and 40 MPa) and stress ratios (1:1, 1:1.5 and 1:2) were chosen as analytical factors. Therefore, dynamic strength parameters and crushing dissipated energy of deep granite considering the in-situ stress environment were captured. These indeed provide design guidance for the establishment of deep rock energy system and prediction of deep dynamic disasters.