In this paper, the velocity values of shear and compressional elastic waves of Phyllite limestone samples obtained both theoretically and
practically are compared. These rock samples were performed in cubic shape.
At the room pressure and temperature, the velocity values for these
samples were measured using the first arrival times of elastic waves along
the mentioned samples. The frequency of compressional waves was 63kHz and that for shear waves was 33 kHz. The velocity values of compressional
and shear waves for different incident angles such as 0, 30, 45, 60 and 90 degress between the receiver and the transducer were measured. In the
theoretical stage, the crack density and dynamically Lame's constants were computed using Budiansky and O'Connel (1974) theory. Then, the
theoretical velocity values of the same samples were calculated based on Hudson (1980) theory.
The obtained results showed that a good correlation exists between the calculated and the measured data for the samples with low crack density.
While for the samples with a high crack density the correlation is poor when the incident angles were at 30, 45 and 60 degrees. This difference
between theory and measurements might be attributed to the presence of inclusions and inhomogeneity in the rock samples.