Site Investigation - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 389

Figure 13.28 Approximation of density functions of strike and dip from frequency distributions
(Wittke 1990)

The orientations of discontinuities whose poles are located in the yellow colored area
of the pole plot represented in Fig. 13.29 are thus to be described by

,
while those whose poles are located in the green colored area are to be described by
=

= α and = β

α - 180° and = - β .