The mechanical properties of the rock masses are influenced by existence of joints and faults. Especially roughness of the discontinuous surfaces determine the strength-deformation characteristics of rock masses.
Barton indicated the influence of the JRC (Joints Roughness Coefficient) for the arbitrary shaped asperities upon the shear strength, shear stiffness and normal stiffness. However, the Barton's shear strength criteria is only applicable to a domain of comparatively small confining pressure where does not get the asperities sheared. off. Ladanyi & Archambault developed a shear strength criteria for the asperities under the shear off condition. This criteria can take account of progressive failure when the asperities leave the initial condition of complete interlocking. The criteria, however, can be only applicable to the case of regular shaped asperities. In order to apply this criteria to analysis of the shear strength of actual rock mass, it is necessary to convert the irregular shape into a regular one.
This study is based on a consideration of the applicability of the Barton's joint roughness as well as Ladanyi & Archambault's shear strength criteria and deals with a transformation of the irregular shaped asperities into a regular one in a discontinuous surfaces.
