The Hoek–Brown Failure Criterion

List of Symbols r1 Major principal stress r3 Minor principal stress Co Uniaxial compressive strength mi Hoek–Brown material constant (intact rock) mb Hoek–Brown material constant (rock mass) s Hoek–Brown material constant a Hoek–Brown material constant GSI Geological Strength Index D Disturbance factor To Uniaxial tensile strength r3max Upper limit of confining stress r Coefficient of...