Experimental Investigation into the Bedding Plane Slip Effect on the Overlying Strata Behavior in Longwall Top Coal Caving of Soft Coal Seam

Table 2

Coal and rock parameters for physical similarity simulation experiment.

No.	Rock stratum	Thickness (m)	Model thickness (cm)	Compressive strength (MPa)	Simulated intensity (KPa)	Similar materials (kg)
						m1	m2	m3	m4
1	Siltstone	28.8	19.2	37	147.97	115.2	14.4	14.4	20.57
2	Medium-grained sandstone	11.7	7.8	54	215.96	46.8	3.51	8.19	8.36
3	Siltstone	26.3	17.5	34	135.97	104.9	13.13	13.13	18.75
4	Coarse-grained sandstone	16.6	11.1	58	231.95	66.6	5	11.66	11.89
5	Siltstone	16.8	11.2	32	127.97	63	14.7	6.3	12
6	Medium-grained sandstone	14.1	9.4	52	207.96	52.88	8.81	8.81	10.07
7	Siltstone	24.9	16.5	35	139.97	98.99	12.38	12.38	17.68
8	Fine sandstone	13.6	9.1	32	127.97	54.59	6.83	6.83	9.75
9	8# coal seam	3.8	2.5	7	28	16.41	1.64	0.7	2.68
10	Siltstone	12.6	8.4	32	127.97	47.24	11.03	4.73	9
11	Fine∼medium-grained sandstone	7.6	5.1	42	167.97	28.69	4.78	4.78	5.46
12	Siltstone	5.7	3.8	30	119.98	21.37	4.99	2.14	4.07
13	9# coal seam	2.4	1.6	7	28	10.5	1.05	0.45	1.71
14	Fine sandstone	10.6	7.1	25	99.98	42.59	7.46	3.2	7.61
15	Dark gray claystone	2.1	1.4	23	91.98	8.4	1.47	0.63	1.5
16	11# coal seam	4.2	2.8	11.2	44.8	18.38	1.83	0.79	3
17	Dark gray claystone	2.5	1.7	20	79.98	10.19	1.79	0.77	1.82
18	Coarse-grained sandstone	20.7	13.8	60	239.95	82.81	6.21	14.48	14.76

Note. m₁, weight of sand; m₂, weight of calcium carbonate; m₃, weight of gyp; m₄, weight of water.