Estimation of the Poisson’s Rate of the Intact Rock in the Function of the Rigidity

Although Poisson’s ratio is one of the basic rock mechanical parameters, it is less investigated than the other parameters. It can be assumed, that this material constant depends on the rigidity of the rock, among the others. The goal of this research is to find a theoretical relationship between the rigidity of the intact rock and Poisson’s ratio. It was assumed that there is a connection between the internal friction angle (or cohesion) and rigidity of the isotropic, linear elastic material, using the Mohr-Coulomb theory. Based on these equations from different published limit equilibrium, six different equations were compared. It is published that the rigidity value is equal (within the experimental error) to the Hoek-Brown material constant (mi) which value is well-known for many different rock types. Plotting the published Poisson’s ratio in the function of the rigidity of the intact rock the optimal connection was chosen.