Abstract
A measurement of sound velocities is one of the useful methods for evaluating elastic moduli of anisotropic rocks. Shear wave velocities have been almost always used in the determination of the elastic constants of rock specimens. However, the identification of direct shear waves in rockmass should often be difficult, due to mode conversion at boundaries and shear wave splitting. The present study discusses how to evaluate elastic moduli of anisotropic rockmass without any observation of shear wave velocity. The simulation study showed that the elastic moduli were very difficult to be determined exclusively by using the sound velocites of quasi-dilatational waves in a practical condition that the velocities in every 15 degree interval in three orthogonal planes with an accuracy of better than 2%. When the gradients of the error-functions with respect to the calculated shear wave velocities were combined with the information of observed dilatational waves, all of the elastic moduli could be effectively determined.
