Study on the Migration Law of Overlying Rock in the Upward Layered Continuous Mining Face of Thick Coal Seam with Paste Backfill Mining

Table 1

Mechanical parameters of coal and rock mass.

No.	Lithology	Thickness (m)	Density (kg/m^3)	Young’s modulus (GPa)	Poisson’s ratio	Internal friction angle (°)	Cohesion (MPa)	Tensile strength (MPa)
1	Topsoil	17.5	1210	0.55	0.44	32.3	0.07	0.15
2	Siltstone	53.5	2570	17.0	0.22	36.5	3.9	2.9
3	Coarse sandstone	20.4	2480	21.5	0.23	32.9	6.8	5.1
4	Mudstone	17.8	2700	18.0	0.21	33.2	6.9	3.8
5	Fine sandstone	24.8	2720	21.0	0.22	38.2	5.6	3.5
6	Siltstone	36.8	2690	18.5	0.22	33.5	6.9	5.2
7	Fine sandstone	9.2	2690	21.0	0.20	39.4	5.6	5.1
8	Medium sandstone	23.7	2170	25.0	0.26	33.0	3.6	3.4
9	Siltstone	14.1	2690	18.5	0.22	34.5	6.3	3.2
10	Mudstone	8.0	2690	19.0	0.20	33.2	6.8	3.8
11	Medium sandstone	4.2	2690	25.0	0.25	34.0	5.8	2.9
12	Fine sandstone	3.0	2730	22.0	0.21	32.5	5.5	4.5
13	Coal	6.7	1200	1.2	0.29	33.0	2.1	1.3
14	Fine sandstone	2.9	2730	22.0	0.26	30.9	7.5	3.4
15	Medium sandstone	5.1	2730	23.0	0.25	31.6	8.0	3.5
16	Mudstone	4.6	2680	21.0	0.23	33.0	7.7	3.0
17	Argillaceous sandstone	7.4	2720	18.0	0.21	33.4	6.0	3.2