Volume 21, Issue 3 (September 1998)
Methods for Predicting Shale Durability in the Field
Durability of shales and other weak rock is an important parameter describing the material's susceptibility to breakdown upon exposure to water or during construction work. While laboratory methods have been developed to measure durability, no correlations between laboratory results and simple field tests have been determined.
The results of this study show that certain field parameters can predict slake durability with acceptable accuracy. The recommended field tests, in order of desirability, are slake index, jar slake, hammer rebound, and NGI “Q” value. Single variable and multiple variable linear regression equations are given, including equations conservatively modified so that 95% of the slake durability values are underpredicted.