Energy Damage Evolution Mechanism of Rock and Its Application to Brittleness Evaluation

Excerpt

The deformation and damage evolution processes in rock are accompanied by energy conversion, including the accumulation, dissipation, and release of energy (Chen et al. 2017; Huang and Li 2014; Xie et al. 2005). The accumulation of energy strengthens the rock, which manifests as an increase in the elastic modulus and a decreased crack volume strain. Meanwhile, the dissipation of energy can gradually damage the rock, resulting in an increase in acoustic emission events and internal cracks. Ultimately, the sudden release of energy represents the unstable failure of the rock (Ma et al. 2016). Therefore, the process of damage evolution in rock is closely linked to the mechanisms of energy conversion; the rock will have different energy conversion characteristics at different loading stages. In addition, the lithology, water content, mineral composition, stress path, and confining pressure of rock can influence its mechanical properties and have a significant effect on the energy damage evolution mechanism (Bagde and Petroš 2009; Hashiba and Fukui 2015; Munoz et al. 2016). …