Rock Mass Classification by Cluster Analysis of Seismic Attenuation Spectra

Abstract

Attenuation spectra of seismic signals obtained in a mine adit were examined using the cluster analysis method in order to correlate with the classification of rock masses.
The results are summarized as follows;
(1) Properties of discontinuity, which are important parameters in the conventional methods of rock mass classification, have a considerable influence on seismic attenuation. We can, therefore, use the character of seismic attenuation as assesments of the fractured state of rock masses.
(2) The results of cluster analysis of attenuation spectra agree with each other in spite of the definitions of dissimilarity between clusters.
(3) Good correspondence is recognized between the result of the conventional rock classification method and the result of classification by cluster analysis of seismic attenuation spectra. It is a feasible method of characterizing of rock masses.