Experimental investigation of fracturing processes under compression of granite specimens containing combined defects using DIC and AE techniques

Cracks and other discontinuities may significantly influence the stability and integrity of the rock mass surrounding underground openings, especially in deep emplacements located in brittle rocks with sparse fractures. Although significant advances in the numerical modeling of such systems have been reported in the past years, there still exists a significant necessity of experimental data providing relevant case studies to verify the applicability and limits of these models. In this work, we present a complete series of unconfined compression experiments in a two-dimensional arrangement using prismatic granite specimens including a central circular hole (representing an underground opening in a brittle rock massif) and a paired arrangement of flaws (accounting for spread discontinuities within the massif) with multiple (up to 7) inclination angles. The experiments include the assessment of stress/strain relationships …