Field Tests - Rock Mechanics Based on an Anisotropic Jointed Rock Model - page 482

where are calculated from

the differential measured displacements. Correspondingly, the second loading stage en-
ables E 2 , G 2 and

β is the dip angle of the isotropic plane and Δ , Δ , Δ

ν 2 from Δ p z , Δ , Δ and Δ to be determined as follows (Fig.

15.18, lower):

(15.34)

(15.35)

(15.36)

The special case β = 0 yields:

(15.32)

(15.33a)

(15.34a)

(15.36a)

If = 90, both loading stages are identical. Therefore in this special case, instead of a

pressure increment

β

Δ p z , a pressure increment Δ p x is required to determine E 2 and ν 2

(Kiehl & Wittke 1983):

(15.32)