Stress-Strain Behavior of Jointed Rock - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 68

If the shape of the open discontinuity sections deviates from that of Griffith cracks the
normal and shear stress distributions along the discontinuity's plane can be qualita-
tively described by the red and orange lines in Fig. 3.16; that is, finite stress values

σ n,IR

and τ res,IR arise at the edges of the discontinuity sections. Also, the distributions of the

local stresses

τ res,IR may be different and Equation (3.61) does not apply any-
more. Equations (3.67) and (3.68), however, are still valid. The failure criterion (3.72)
is therefore also valid for one-dimensional, non-persistent discontinuities with irregular
ordered open sections of differing lengths.

σ n,IR and

Figure 3.16 Qualitative stress distribution along the rock bridges of a one-dimensional
non-persistent discontinuity with open discontinuity sections