Numerical Study on Anisotropy of the Representative Elementary Volume of Strength and Deformability of Jointed Rock Masses

Representative elementary volume (REV) is a significant parameter in analyzing the size effect and the continuous media theory of natural jointed rock masses. Generalized RVEs, which include the REV of jointed rock masses (RREV) and the REV of mechanical parameters of jointed rock masses ( PREV), were introduced and investigated based on the anisotropy of natural jointed rock masses. A two-dimensional model was developed based on the available geology, material heterogeneity and Monte Carlo simulation of joint network. The size effect and anisotropy of the elastic modulus and the uniaxial compressive strength (UCS) of jointed rock masses were investigated, and then, the PREV was determined. Numerical results showed that the PREVs for both the elastic modulus and UCS exhibited strong anisotropy. The RREV dimension was determined as 14 x 14 m based on the PREV of different rotational directions. The equivalent mechanical parameters of the elastic modulus and UCS were determined for different rotational directions. It is suggested that the anisotropy of the PREV should be considered when the RREV and corresponding equivalent mechanical parameters are assessed.