Rock Strength Evaluation during Progressive Failure Process Based on Fractural Characterization

A series of laboratory tests was performed to study the decrease of the rock strength during its progressive failure process. Hoek–Brown criterion was adopted as the means to estimate rock strength. The parameters m and s of the criterion for different stages of progressive failure process were derived from the results of triaxial tests. To better evaluate the strength changes over a very wide range of length scales, fractals were introduced to...