Movement Law and Discriminant Method of Key Strata Breakage Based on Microseismic Monitoring

Table 2

Identification of the KS in working face 11203.

Number	Thickness (m)	Depth (m)	Name	Hard rock	KS
38	7.00	7.00	Silty-fine sand
37	28.72	35.72	Fine-silty sand
36	13.69	49.41	Sandy loam
35	15.24	64.65	Medium-grained feldspar sandstone	Yes	Main KS (composite KS, combined two hard rock strata)
34	5.50	70.15	Mudstone
33	26.67	96.82	Fine feldspar sandstone	Yes
32	6.87	103.69	Sandstone
31	14.87	118.56	Siltstone
30	8.49	127.05	Silty mudstone
29	7.89	134.94	Fine feldspar sandstone
28	6.43	141.37	Mudstone
27	29.67	171.04	Fine feldspar sandstone	Yes	Inferior KS 4
26	9.54	180.58	Siltstone
25	10.87	191.45	Mudstone
24	6.77	198.22	Fine feldspar sandstone
23	3.99	202.21	Mudstone
22	3.33	205.54	Fine feldspar sandstone
21	3.30	208.84	Mudstone
20	6.89	215.73	Fine feldspar sandstone
19	7.29	223.02	Silty mudstone
18	3.44	226.46	Mudstone
17	8.90	235.36	Silty mudstone
16	9.49	244.85	Fine feldspar sandstone	Yes	Inferior KS 3 (composite KS, combined two hard rock strata)
15	6.68	251.53	Silty mudstone
14	9.39	260.92	Pelitic siltstone
13	10.05	270.97	Fine feldspar sandstone	Yes
12	5.30	276.27	Mudstone
11	7.63	283.90	Silty mudstone
10	11.29	295.19	Mudstone
9	11.53	306.72	Medium-grained feldspar sandstone	Yes	Inferior KS 2
8	11.80	318.52	Silty mudstone
7	6.20	324.72	Coarse feldspar sandstone
6	3.99	328.71	Silty mudstone
5	1.64	330.35	Fine feldspar sandstone
4	7.17	337.52	Silty mudstone
3	7.51	345.03	Fine feldspar sandstone	Yes	Inferior KS 1
2	3.99	349.02	Silty mudstone
1	2.95	351.97	Coal stratum 2^#