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

Table 1

Initial stress level.

Type	Initial stress (MPa)			Unloading point (MPa)	Unloading rate of (MPa·s^−1)
	Loading test	20	5, 11, 17, 20	5	–	–
Lateral unloading test	20	5, 11, 17, 20	5		0.05