Correlations between punch test results and rock physical properties

A series of punch indentation tests were run in the late 1970's to determine if any correlations exist between the results of that test and other physical properties of rock. The tests were run on eight rocks from a standard suite provided by the USBM. The results of the study show that the strongest correlations exist between unconfined compressive strength and many of the punch test parameters. They also show that;significant correlations occur between Shore Hardness and these parameters. Based on this and on the similarity between the way in which rock samples fail in the punch test and rock fails beneath button and disk cutters, it is concluded that both physical properties could be used as a basis for estimating the instantaneous penetration rates of raise and tunnel boring machines.