Table 2 The measured points of failure at the stress space for the sandstone (recalculated values)24.

From: Brittle-ductile transition stress of different rock types and its relationship with uniaxial compressive strength and Hoek–Brown material constant (mi)

No. samples

Confining pressure (σ3 = σ2) (MPa)

Axial pressure (σ1) (MPa)

I

0

70

II

28

235

III

56

318

IV

157

491

V

251

Min. 717