Study of Cracking Process in Granite

Behavior of intact brittle rocks during loading is characterized by a micro-cracking process, which occurs due the presence of flaws in their microscopic structure, propagating through the intact rock leading to shear fracture. This fracturing process is of fundamental importance as it affects the mechanical properties of the rock. The purpose of the present study is to investigate the fracture mechanism and specifically detect the crack initiation and crack damage stresses in a granite rock. For this purpose, stress-strain data were recorded and the acoustic emission method was used in uniaxial compression tests. The results from both methods correlate well and show that the crack initiation and crack damage thresholds are about 46% and 78% of the uniaxial compressive strength of the intact rock respectively, slightly higher than the results reported in literature from previous studies in granite.