Investigation on the Ground Pressure Induced by Hard Roof Fracturing at Different Layers during Extra Thick Coal Seam Mining

Table 3

Parameters of the coal and rock.

No.	Lithology	Depth (m)	Thickness (m)	Simulated thickness (cm)	Compression strength (MPa)	Simulated strength (KPa)	Matching number	Weight (kg)	Sand (kg)	Calcium carbonate (kg)	Gypsum (kg)	Water (kg)
1	Gritstone	267.01	4.9	3.3	28.34	113.36	373	29.4	22.05	5.15	1.65	4.20
2	Packsand	271.91	12.1	8.1	90.53	362.12	437	72.6	58.08	4.36	8.13	8.07
3	Siltite	284.01	3.7	2.5	33.6	134.4	737	22.2	19.43	0.83	1.70	2.47
4	Gritstone	287.71	2.8	1.9	23.1	92.4	473	16.8	13.44	2.35	0.81	1.87
5	Pebblestone	290.51	4.5	3.0	35.6	142.4	555	27	22.50	2.25	1.88	3.00
6	Gritstone	295.01	5	3.3	25.9	103.6	755	30	26.25	1.88	1.64	3.33
7	Conglomerate	300.01	5	3.3	37.74	150.96	455	30	24.00	3.00	2.40	3.33
8	Siltite	305.01	5	3.3	24.1	96.4	473	30	24.00	4.20	1.44	3.33
9	Packsand	310.01	12.9	8.6	80.21	320.84	337	77.4	58.05	5.81	10.16	11.06
10	Gritstone	322.91	5	3.3	26.6	106.4	755	30	26.25	1.88	1.64	3.33
11	Medium sandstone	327.91	4.8	3.2	30.3	121.2	655	28.8	24.69	2.06	1.76	3.20
12	Siltite	332.71	3	2.0	35.87	143.48	555	18	15.00	1.50	1.25	2.00
13	Conglomerate	335.71	5.2	3.5	25.6	102.4	755	31.2	27.30	1.95	1.71	3.47
14	Pebblestone	340.91	5.4	3.6	32.3	129.2	737	32.4	28.35	1.22	2.48	3.60
15	Siltite	346.31	4	2.7	23.57	94.28	473	24	19.20	3.36	1.15	2.67
16	Packsand	350.31	12.2	8.1	80.27	321.08	337	73.2	54.90	5.49	9.61	10.46
17	Gritstone	362.51	5.7	3.8	32.87	131.48	737	34.2	29.93	1.28	2.62	3.80
18	Conglomerate	368.21	3.3	2.2	22.9	91.6	473	19.8	15.84	2.77	0.95	2.20
19	Siltite	371.51	3	2.0	33.85	135.4	737	18	15.75	0.68	1.38	2.00
20	Medium sandstone	374.51	4.83	3.2	30.24	120.96	655	28.98	24.84	2.07	1.77	3.22
21	Siltite	379.34	5	3.3	23.23	92.92	473	30	24.00	4.20	1.44	3.33
22	Packsand	384.34	10.12	6.7	65.53	262.12	337	60.72	45.54	4.55	7.97	8.67
23	Pebblestone	394.46	5.6	3.7	30.23	120.92	373	33.6	25.20	5.88	1.89	4.80
24	Mudstone	400.06	5.8	3.9	25.3	101.2	755	34.8	30.45	2.18	1.90	3.87
25	Conglomerate	405.86	3.8	2.5	29.13	116.52	373	22.8	17.10	3.99	1.28	3.26
26	Siltite	409.66	5.25	3.5	36.56	146.24	555	31.5	26.25	2.63	2.19	3.50
27	Packsand	414.91	9.1	6.1	55	220	437	54.6	43.68	3.28	6.12	6.07
28	Siltite	424.01	6.4	4.3	30.73	122.92	655	38.4	32.91	2.74	2.35	4.27
29	Conglomerate	430.41	3.2	2.1	23.6	94.4	473	19.2	15.36	2.69	0.92	2.13
30	Medium sandstone	433.61	4	2.7	30.43	121.72	655	24	20.57	1.71	1.47	2.67
31	Gritstone	437.61	5.05	3.4	38.6	154.4	455	30.3	24.24	3.03	2.42	3.37
32	Packsand	442.66	9.44	6.3	55.53	222.12	437	56.64	45.31	3.40	6.34	6.29
33	Sandy mudstone	452.1	5.65	3.8	33.3	133.2	737	33.9	29.66	1.27	2.60	3.77
34	Conglomerate	457.75	3.2	2.1	23.34	93.36	473	19.2	15.36	2.69	0.92	2.13
35	Siltstone	460.95	4.5	2.9	21.07	84.28	573	26.4	22.00	3.08	1.10	2.93
36	Mudstone	465.35	4.3	2.9	17.36	69.44	773	25.8	22.58	2.26	0.85	2.87
37	#3-5 coal seam	469.65	20	13.3	15.94	63.76	773	120	105.00	10.50	3.94	13.33
38	Gritstone	489.65	3	2.0	43.87	175.48	637	18	15.43	0.77	1.54	2.00