Influence of Upper Seam Extraction on Abutment Pressure Distribution during Lower Seam Extraction in Deep Mining

Table 1

Coefficients of influence of the key strata on advanced abutment pressure of panel Y485.

No.	Distance to No. 9 seam (m)	Thickness (m)	Coefficient of influence (δ)
Key stratum 1	8.49	14.57	0.37
Key stratum 2	47.26	5.39	0.22
Key stratum 3	96.64	15.09	0.10
Key stratum 4	121.74	34.72	0.10
Key stratum 5	253.65	15.85	−0.35
Primary key stratum	388.85	61.99	−0.59