Mechanism and Control of Roadway Floor Rock Burst Induced by High Horizontal Stress

Table 2

Mechanical parameters for surrounding rock and coal.

Rock	Density（g·cm^−3）	Cohesion (MPa)	Internal friction angle (φ)（°）	Elasticity modulus (E) (MPa)	Poisson ratio (μ)
Overlying rock	2.61	20	35	7000	0.30
Fine sandstone	2.75	8.9	33.4	4560	0.19
Mudstones	2.51	0.97	26	4560	0.31
Medium sandstone	2.48	4.7	36	4800	0.27
Coal	2.61	20	38	8600	0.25