The potential of sonic wave propagation in engineering rock classification

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Virginia Polytechnic Institute and State University


Sonic wave methods can be used to provide information on the engineering properties of rocks. The advantages of such techniques include minimal sample preparation, fast site preparation for field tests, reproducible and nondestructive tests, and capability for large scale testing.

During this research an extensive review of the most widely accepted engineering rock classification systems was undertaken and their principles, advantages and disadvantages are presented in detail.

The mathematical equations describing wave propagation through elastic and viscoelastic media are analyzed in order to determine the dynamic parameters most likely related to static properties.

A detailed description of the instrumentation and experimental procedures used for sonic testing is presented. Based on the experimental data, a correlation between the most characteristic static and dynamic properties was established. These relationships can be used to modify existing engineering rock classification systems, by appropriately substituting static properties by the much easier to measure, in the field and in the laboratory, sonic wave parameters. Furthermore, a classification scheme was developed, incorporating information pertaining to the static modulus of elasticity and frequency of joints from sonic wave information.