Improving the Stability of Subsurface Structures in Deep Metal Mines by Stress and Energy Adjustment: A Case Study

Table 2

Designed mining schemes of test stope.

Mining method	Simulated mining scheme	Stress boundary
Scheme 1: the upward horizontal backfill method	Step 1: excavating an undercut roadway of 4 m × 4.5 m in the middle of a stope	Initial Szz −26.6 MPa
	Step 2: excavating north of stope	Initial Sxx −43.6 MPa
	Step 3: excavating south of stope	Initial Syy −26 MPa
	Step 4: backfilling height of 3 m with the roof uncontacted
Scheme 2: the approaching backfill method	Step 1: excavating 4 approaching roads in the stope from the middle to the north	Initial Szz −26.6 MPa
	Step 2: excavating 3 approaching roads in the south of stope	Initial Sxx −43.6 MPa
	Step 3: backfilling the 7 roads with the roof contacted	Initial Syy −26 MPa
	Step 4: excavating the remained 8 roads
	Step5: backfilling the 8 roads with the roof contacted