Propagation des ondes dans les roches anisotropes sous contrainte évaluation de la qualité des schistes ardoisiers

The propagation velocity of longitudinal waves has been measured on slates with various fissilities. The cylindrical bars used for those measurements were cut along the characteristic lines of the fabric of those schists and were submitted to an axial stress. This method clearly points out the influence of the fabric (orientation of the minerals and discontinuities) and of the development of the stress cracking. It may be usefully applied for the evaluation of the quality of schists used for the production of roofing slates.