Unloading Mechanics and Energy Characteristics of Sandstone under Different Intermediate Principal Stress Conditions

Table 2

Fitting parameters of sandstone under different stress paths.

Loading method	Mogi–Coulomb criterion
	a	b	c (MPa)	(°)
True triaxial loading	11.063	0.796	21.90	57.60	0.996
True triaxial lateral unloading	10.387	0.704	16.56	48.31	0.999