THE BLOCK FAILURE LIKELIHOOD - A CONTRIBUTION TO ROCK ENGINEERING IN BLOCKY ROCK MASSES

This paper summarizes some results of an applied block theory research conducted at Berkeley over the last three years. The validity of the critical-key-block concept is tested here using block mould statistics sampled from side walls of two tunnels, the raw data of which are shown. The predictive capabilities of the three block-failure-likelihood parameters are tested by correlation with the block mould sample population, and a modification is introduced. A possible method to integrate a block motion criteria in empirical rock mass classification systems is proposed.