The use of recording drilling parameters in rock-mass classification

Limestone quality classification is attempted by means of digital recording of parameters during destructive percussion drilling. A new combined parameter, the Variability Index is proposed which is based on the percussion energy reflected from the drilling bit. The new parameter is shown to be well suited for the classification of the limestone quality, at least in the site studied. Furthermore, this parameter is shown to be very effective in the detection of inclusion cavities in carstic limestone.