Research on Surrounding Rock Stability Affected by Surrounding Rock Pressure and Rock Fracture under Blasting Vibration Load Action

Table 4

Proportions of primary and secondary frequency bands in the increase amplitude of total energy in frequency bands at monitoring points 5∼8 (%).

Variation of confining pressure	Monitoring point 5		Monitoring point 6		Monitoring point 7		Monitoring point 8
	Primary	Secondary	Primary	Secondary	Primary	Secondary	Primary	Secondary
1∼4 MPa	52.06	45.94	51.23	46.77	42.06	55.94	41.33	56.67
4∼8 MPa	52.95	45.05	51.86	46.14	42.78	55.22	42.05	55.95
8∼12 MPa	53.29	44.71	52.07	45.93	42.75	55.25	42.06	55.94
12∼16 MPa	53.40	44.60	52.20	45.80	43.03	54.97	42.31	55.69
16∼20 MPa	53.54	44.46	52.21	45.79	43.07	54.93	42.32	55.68