ABSTRACT
A great number of rock strength criteria have been proposed over the past three decades (Hoek & Brown, 1980; Yudhbir et al., 1983; Sheorey et al., 1989; Yoshida, 1990; Ramamurthy, 2001). Of these different strength criteria, the Hoek-Brown strength criterion has been the most well-known and most frequently used one, because: (a) it was developed specifically for rock materials and rock masses; (b) its input parameters can be determined from routine unconfined compression tests, mineralogical examination, and discontinuity characterization; and (c) it has been applied for over 20 years by practitioners in rock engineering, and has been applied successfully to a wide range of intact and fractured rock types.
