Study on the Migration Law of Overlying Strata on the Working Surface of Large Mining Height in Y.C.W Coal Mine

Table 1

Mechanical parameters of overlying rock of working face and identification of key horizon.

No.	Rock name	Tensile strength (MPa)	Elastic modulus (GPa)	Poisson ratio	Cohesion (MPa)	Angle of internal friction (°)	Density (kg/m^3)	Thickness (m)	Depth (m)	Key strata location
1	Silty mudstone	2.64	1.14	0.22	4.27	39.2	2200	27	309
2	Siltstone	2.4	1.39	0.22	9	42	2600	4	313
3	Medium sandstone	3.12	0.85	0.22	7	39.2	2500	48	361	Main key stratum
4	Mudstone	1.5	0.78	0.34	6.89	24.7	2350	15	376
5	Fine sandstone	3.86	1.44	0.23	4.83	52.4	2350	7	383
6	Mudstone	1.15	0.56	0.34	6.89	24.7	2350	6	389
7	Fine sandstone	3.51	1.52	0.23	4.83	52.4	2350	6	395
8	Silty mudstone	2.64	1.14	0.22	4.27	39.2	2200	22	417
9	Medium sandstone	3.12	0.82	0.23	7	39.7	2500	2	419
10	Grit stone (with water)	3.27	1.46	0.23	4.66	46.7	2350	51	470	Inferior key strata II
11	1# coal seam	1.32	0.67	0.25	0.75	40.2	1500
12	Siltstone	2.4	1.39	0.22	9	42	2600	1	471
13	Medium sandstone	3.05	1.82	0.23	7	39.7	2500	3	474
14	Fine sandstone	3.79	1.22	0.23	4.83	52.4	2350	15	489	Inferior key strata I
15	Siltstone	2.35	1.28	0.22	9	42	2600	3	492
16	2# coal seam	1.35	0.71	0.25	0.75	40.2	1500	2	494
17	Mudstone	1.57	0.68	0.34	6.89	24.7	2350	8	502