Experimental Investigations on Rheological Properties of Mudstone in Kilometer-Deep Mine

Table 4

Unloading confining pressures with axial compression triaxial test scheme.

Load classification	I	II	III	IV	V	VI	VII
σ1 (MPa)	30	40	50	55	60	65	65
σ3 (MPa)	20	15	10	8	5	3	2
σ1−σ3 (MPa)	10	25	40	47	55	62	63