EVALUATION OF ULTRASOUND EMISSION FOCI IN LOADING ROCK SAMPLES

Abstract

Laboratory experiments proved that during loading of rock samples the migration of ultrasound signals (US) foci occurred in the volume of sample. There is distribution of US foci analysed in this paper. On the base of ultrasonic signals location the segments of higher concentration were determined. For the purpose of the assessment of detailed future part of total rupture the whole volume of the rock sample was divided in eight segments. The experiments were carried out for various loading rate. Detailed analysis, based on the cross-correlation of the foci number in the separate segments, proved that the occurrence of US in the individual segments are mutually influenced. The results indicate that the used correlation method allowed to assess the future part of the total sample fracture.