Mechanism and Energy Evolution Characteristics of Coal Burst in Mining Thick, Deep, and Large Inclined Coal Seams: A Case Study from a Chinese Coal Mine

Table 1

Main coal and rock mechanical parameters.

Lithology	Density (kg·m^-3)	Bulk modulus (GPa)	Shear modulus (GPa)	Internal friction angle (°)	Cohesion (MPa)	Tensile strength (MPa)
No. 7 coal	1350	2.1	1.2	30	1.4	2.45
No. 8 coal	1380	1.9	0.9	29	1.2	2.3
Mudstone	2550	5.8	2.8	31	4.2	2.83
Sandy mudstone	2560	6.3	2.9	32	5.4	3.35
Fine-grained sandstone	2610	11.2	6.0	34	7.1	10.4
Siltstone	2595	7.1	3.5	36	8.2	5.04
Medium grained sandstone	2655	10.2	5.3	35	8.2	8.15
Coarse-grained sandstone	2640	8.1	4.2	33	9.3	6.84