A study of acoustic emission from stressed rock

Abstract

Acoustic emission is generated in stressed materials as a result of internal deformation and may, therefore, be used to examine the failure mechanisms of materials within the laboratory and in situ. The literature relating to acoustic emission is reviewed, particular attention being given to experimental systems for the detection, recording and analysis of such emissions, the interpretation of the acoustic record and the practical application of acoustic techniques in rock mechanics. An experimental acoustic system, developed for use both in the laboratory and the field, and the ancillary loading equipment are described. The methods of processing and analysing the acoustic record are illustrated by reference to a series of laboratory tests on a variety of rock samples. Various parameters are described, including pulse rate, signal energy content and amplitude distribution; the variation of these parameters during uniaxial loading of rock specimens is described. © 1968.