A statistical approach for determining practical rock strength and deformability values from laboratory tests

The present paper focuses on a rigorous procedure using statistical inference leading to the determination of practical laboratory strength and deformability parameters obtained on rock specimens. Using statistical inference, upper or lower bounds of deformability properties can be obtained following a methodology involving chosen confidence interval and precision index along with statistical parameters of laboratory test results. A similar approach gives strength property bounds, which insure failure or nonfailure with a given probability. These property values can then be used with appropriate extrapolation models to estimate the rock mass strength.