Calculate the Hoek and Brown criterion based on the data, not the Griffith criterion:

Internal friction angle - 54.59

Uniaxial compressive strength-8850psi

Cohesion -900psi

 

Class 1 2 23 3 4 5 6 S1 (psi) 0 8850 14925 20900 30900 62887 S2 (psi) 890 0 1000 2000 3000 6000