RESEARCH ON MICRO-MESO CHARACTERISTICS OF GRANITE FRACTURE UNDER UNIAXIAL COMPRESSION AT LOW AND INTERMEDIATE STRAIN RATES
LIANG Changyu1，2，WU Shuren1，2，LI Xiao3
(1. Key Laboratory of Neotectonics Movement and Geohazards，Ministry of Land and Resources，Institute of Geomechanics，Chinese Academy of Geological Sciences，Beijing 100081，China；2. Institute of Geomechanics，Chinese Academy of Geological Sciences，Beijing 100081，China；3. Key Laboratory of Engineering Geomechanics，Institute of Geology and Geophysics，Chinese Academy of Sciences，Beijing 100029，China)
Abstract：The macroscopic fracture modes and the micro-meso morphology are the important characteristics to represent rock failure mechanism. The shear failure mode is the main macro fracture mode of the granite under low and intermediate strain rates. The mesoscopic morphology was studied using scanning electron microscope(SEM) and 3D laser scanner，and the roughness of the fractured surface was quantitatively studied based on fractal theory. The research results show that with increasing strain rates，the main fracture modes change from intergranular fracture，intergranular fracture and cleavage fracture，transgranular with curved path to transgranular with straight path. Based on the research results of micro-meso fracture modes，it has been concluded that the difference of strain rates leads to the difference of energy absorption and the differences of the fracture morphology of rock，which finally leads to the rate sensitivity of rock strength.
LI H，ZHAO J，LI J，et al. Experimental studies on the strength of different rock types under dynamic compression[J]. International Journal of Rock Mechanics and Mining Sciences，2004，41(1)：68-73.
2015, Vol. 34 
