Research on Energy and Instability Criterion of Sandstone Hydraulic Fracturing in the Three Gorges Reservoir Area, Chongqing, China

Table 2

The Mechanical parameters of conventional uniaxial (triaxial) compression failure.

Test classification	Failure characteristics	Fracture angle	Internal friction angle	Adhesive force	P/C
		, °	, °	C/MPa
Conventional uniaxial	Single bevel shearing	76	62	6.36	1.92
Conventional triaxial	Single bevel shearing	67	44	8.24	2.28