Calculation Method of Overburden Damage Height Based on Fracture Mechanics Analysis of Soft and Hard Rock Layers

Table 2

Overlying rock thickness and its mechanical parameters of N1102 working face.

Number	Thickness (m)	Rock name	Density (kN·m^−3)	Tensile strength (MPa)	Elastic modulus (GPa)
20	40.61	K8 sandstone	25.31	7.87	36.01
19	5.3	Sandy mudstone	21.64	5.61	18.35
18	12.56	Fine sandstone	26.45	8.81	36.79
17	4.6	Mudstone	25.98	1.14	18.46
16	9.6	Sandy mudstone	23.64	5.61	18.35
15	3.3	Siltstone	25.46	5.12	24.55
14	0.47	Coal seam	10.36	1.27	4.2
13	4.52	Sandy mudstone	26.23	5.81	18.46
12	3.37	Coarse sandstone	25.64	5.34	21.31
11	10.27	Fine sandstone	27.54	6.88	32.87
10	3.5	Mudstone	24.68	4.17	18.35
9	4.3	Fine sandstone	26.73	6.14	28.33
8	3.2	Sandy mudstone	25.98	5.81	18.46
7	3.58	Fine sandstone	26.73	6.14	29.57
6	3.07	Siltstone	25.2	3.52	24.13
5	3.14	Mudstone	23.68	1.14	18.35
4	3.35	Siltstone	25.1	4.52	23.17
3	3.82	Fine sandstone	26.73	6.14	29.09
2	6.03	Medium sandstone	26.82	8.11	35.62
1	5.12	Mudstone	24.68	1.04	18.35
	6.3	3# coal seam	14.45	3.19	6.7