OBSERVATIONS ON THE VARIATION IN ACOUSTIC EMISSIONS WITH CHANGES IN ROCK CUTTING CONDITIONS

ABSTRACT: The emission of acoustic signals or micro seismic activity in rock subjected to stress is a well established phenomenon that has been exploited in geomechanics for example to understand changes in stress levels around excavations in active mine areas. Another potential application is in the area of rock cutting. The finding of a study to investigate whether changes in rock cutting conditions are reflected in the nature of acoustic signals generated in rock is presented. A test facility was established comprising a linear rock cutting machine, acoustic transducer and data acquisition system. The study examined changes between a new and worn cutter pick and in depth of cut as well as the effect of attenuation of the acoustic signal with distance. The results show that there were measurable changes in the acoustic signal. Further work is suggested to expand on the range of variables considered, for example changes in rock mass type and structure