Understanding the Distribution Laws of In Situ Stress in Mines Based on Global Positioning System Data and Numerical Simulation Analysis

Table 1

Borehole B22 key layer discrimination results.

Number	Strata	Lithology	Thickness (m)	Distance to coal seam (m)	Discriminatory results
1		Wind-accumulated sand	130.38	500.41
2		Siltstone	65.91	434.5	Key layer
3		Fine-grained sandstone	29.75	404.75
4		Medium sandstone	15.98	388.77
5		Fine-grained sandstone	8.84	379.93
6		Silty mudstone	14.05	365.88
7		Fine-grained sandstone	3.3	362.58
8		Coarse-grained sandstone	30.34	332.24	Key layer
9		Mudstone	5.5	326.74
10		Fine-grained sandstone	16.31	310.43
11		Coarse-grained sandstone	45.03	265.4
12		Silty mudstone	40.05	225.35
13		Medium sandstone	7.2	218.15
14		Silty mudstone	57.94	160.21
15		Medium sandstone	6.63	153.58
16		Mudstone	1.4	152.18
17		Medium sandstone	12.17	140.01
18		Silty mudstone	41.12	98.89
19		Coarse-grained sandstone	61.57	37.32	Key layer
20		Fine-grained sandstone	1.7	35.62
21		Mudstone	0.4	35.22
22		Coal	1.3	33.92
23		Fine-grained sandstone	20.76	13.16	Key layer
24		Medium sandstone	1.3	11.86
25		Fine-grained sandstone	11.86	0
26		Coal	5.3
27		Silty mudstone	8.88