Introduction
The most of 3 failure criterias of rock were application as follow
1. The Mohr-Coulomb criterion expresses the relation between the shear stress and the normal stress at failure.
2. The plane Griffith criterion expresses the uniaxial tensile strength in terms of the strain energy required to propagate microcracks, and expresses the uniaxial compressive strength in terms of the tensile strength.
3. The Hoek-Brown criterion is an empirical criterion derived from a ‘best- fit’ to strength data plotted in space.