Study on Stability of Stope Surrounding Rock under Repeated Mining in Close-Distance Coal Seams

Table 1

Parameters for different rocks tested.

Category	Density, kg/m^3	Cohesion, MPa	Bulk, GPa	Shear, GPa	Tension, MPa
Medium sandstone	2600	4.90	8.38	7.96	4.56
Siltstone	2540	3.20	6.85	5.47	3.86
Fine sandstone	2600	3.38	5.27	4.69	3.35
Mudstone	2450	1.24	4.16	2.83	3.02
Sandy mudstone	2500	1.34	4.36	2.53	3.52
Silty mudstone	2550	1.43	4.56	3.23	3.32
Coal	1350	0.50	3.95	2.20	1.04