Overlying Strata Movement Laws Induced by Longwall Mining of Deep Buried Coal Seam with Superhigh-Water Material Backfilling Technology

Table 1

Mechanical parameters of coal seam and overlying strata.

No.	Lithology	Density (kg·m^−3)	Bulk modulus (GPa)	Tensile strength (MPa)	Shear modulus (GPa)	Cohesion (MPa)	Friction angle (°)
1	Fine sandstone	2597	7.2	3.13	4.9	12.0	36
2	Mudstone	2529	7.5	1.38	3.0	12.0	26
3	No. 3 coal seam	1540	5.8	1.25	1.2	3.0	33
4	Siltstone	2575	5.8	1.90	3.6	17.0	40
5	Sandy mudstone	2500	5.7	0.21	3.4	1.3	30
6	Medium sandstone	2660	7.0	1.03	4.2	13.0	44