Influence of Mine Earthquake Disturbance on the Principal Stress of the Main Roadway near the Goaf and Its Prevention and Control Measures

Table 1

Physical and mechanical parameters of surrounding rock.

Rock formation	Bulk modulus (GPa)	Shear modulus (GPa)	Density (kg·m^-3)	Cohesion (MPa)	Internal friction angle (°)	Uniaxial tensile strength (MPa)
Mudstone	6.08	3.47	2 480	1.2	30	0.61
Silty sandstone	10.8	8.13	2 460	2.75	38	2.67
Coarse sandstone	12	8	2 700	2.0	45	0.2
Silty sandstone	10.8	8.13	2 460	2.75	38	2.67
Coarse sandstone	12	8	2 700	2.0	45	0.2
Silty sandstone	10.8	8.13	2 460	2.75	38	2.67
Coarse sandstone	12	8	2 700	2.0	45	0.2
Silty sandstone	10.8	8.13	2 460	2.75	38	2.67
4# coal	4.9	2.01	1 380	1.25	32	0.15
Mudstone	6.08	3.47	2 480	1.2	30	0.61
Coarse sandstone	12	8	2 700	2.0	45	0.2
Medium sandstone	11	8.5	2 820	3.2	42	1.29