Relationships between Strength and Strain Quantities under Brittle Compression Process of Hard Rocks

The aim of this paper is to examine the relationships between strength properties and strain quantities associated with the brittle compression process of hard brittle rocks. From literature searches no experimental result has been published, which describe the relationship between strength properties (uniaxial compression strength, UCS, elastic modulus, E, and v) and strain quantities (critical volumetric strain at strength failure, maximum total volumetric strain,) under failure-deformation process of hard rocks. Most of the published research works have been focused on crack damage stress (σ_cd) and uniaxial compressive strength (σ_c) of characteristic stress levels during compression. The strength properties and the strain quantities were coordinated such that each of the strain quantities or their ratios is compared individually with the strength properties of the rocks to see if there exists a relationship. The relationships between the strength properties and strains quantities as determined in this paper point to the fact that the stability of any engineering structure or excavations depends on the interaction(s) between the strength properties and strains quantities. In addition, the relationships can improve our knowledge to evaluate correctly the stability of excavations, designing of stable structures such as tunneling and excavations for mining and civil engineering applications. The results and finding are presented in this work.