References

Equations

Maximum value of UCS (MPa)

D’Andrea et al. (1964) [1]

UCS = 15.3 PLS + 16.3

350

Broch and Franklin (1972) [2]

UCS = 23.7 PLS

250

Bieniawski (1974; 1975) [3] [4]

UCS = 23 PLS

350

Brook (1977; 1980) [5] [6]

UCS = 12.5 PLS

300

Hassani et al. (1980) [7]

UCS = 29 PLS

200

ISRM Commission (1985) [8] ; Brook (1985) [9]

UCS = 20∙∙∙25 PLS

250

Hikita and Kikuchi (1988) [10]

UCS = 12.3∙∙∙15.0 PLS

200

Kahraman (2001) [11]

UCS = 23.62 PLS − 2.69

150

Kahraman (2001) [11]

UCS = 8.41 PLS + 9.51

150