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

Table 3

Proportions of primary and secondary frequency bands in the increase amplitude of total energy in frequency bands at monitoring points 1∼4 (%).

Variation of confining pressure	Monitoring point 1		Monitoring point 2		Monitoring point 3		Monitoring point 4
	Primary	Secondary	Primary	Secondary	Primary	Secondary	Primary	Secondary
1∼4 MPa	63.25	34.75	62.30	35.70	60.20	37.80	58.15	39.85
4∼8 MPa	63.06	34.94	62.81	35.19	60.65	37.35	58.89	39.11
8∼12 MPa	63.02	34.98	62.97	35.03	60.75	37.25	59.01	38.99
12∼16 MPa	63.04	34.96	63.04	34.96	60.90	37.10	59.27	38.73
16∼20 MPa	63.00	35.00	63.11	34.89	60.90	37.10	59.28	38.72