::k is the ratio of the average horizontal stress to the vertical stress.
::k is the ratio of the average horizontal stress to the vertical stress.
−
The ratio (k) can be determined using the simplified equation provided by Sheorey (1994):
+
The ratio (k) can be determined using the simplified equation provided by Sheorey<ref>Sheorey, P. R., 1994, A theory for in situ stresses in isotropic and transverseley isotropic rock: International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, vol. 31, no. 1, p. 23-34</ref>