Numerical Study on the Mechanism and Application of Artificial Free Surfaces in Bedrock Blasting of Shield Tunnels

Table 13

Peak values and average reduction degree of the vibration velocity in the direction.

Distance (cm)	Diameter (mm)	Peak vibration velocity of particle in direction (cm/s)					(%)
		No. 1	No. 2	No. 3	No. 4	No. 5
60	100	1.27	0.96	0.88	0.91	1.01	54.8
	160	1.19	0.92	0.78	0.73	0.85	50.2
	200	1.13	0.81	0.63	0.74	0.79	63.2
	250	1.08	0.81	0.61	0.72	0.75	64.7
	300	1.05	0.78	0.59	0.72	0.76	65.2
65	100	1.39	0.98	1.01	0.86	0.95	53.9
	160	1.2	0.87	0.78	0.87	0.85	59.2
	200	1.15	0.88	0.75	0.71	0.76	62.3
	250	1.11	0.86	0.72	0.68	0.72	63.7
	300	1.06	0.88	0.69	0.65	0.71	64.6
70	100	1.54	1.12	0.95	0.95	1.04	50.2
	160	1.29	0.91	0.8	0.85	0.91	57.6
	200	1.18	0.89	0.72	0.79	0.83	60.6
	250	1.13	0.87	0.67	0.67	0.81	63.1
	300	1.09	0.85	0.71	0.66	0.78	63.5
75	100	1.67	1.18	1.08	1.01	1.09	46.4
	160	1.35	0.97	0.96	0.89	0.93	54.6
	200	1.24	0.91	0.76	0.79	0.85	59.5
	250	1.18	0.87	0.69	0.76	0.82	61.6
	300	1.14	0.86	0.72	0.77	0.79	61.9
80	100	1.76	1.18	1.06	1.05	1.08	46.1
	160	1.43	1.05	1.01	0.88	0.85	53.8
	200	1.32	0.94	0.83	0.79	0.77	58.9
	250	1.25	0.94	0.81	0.73	0.69	61.1
	300	1.19	0.91	0.83	0.72	0.68	62.2