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

Table 11

Decreasing degree of the peak vibration velocity of particles.

Particle no.	Distance from the center of the hole (cm)	Reduction degree of the peak vibration velocity (%)
		Group A	Group B	Group C	Group D	Group E
1	40	55.72	59.24	66.97	71.39	71.45
2	80	77.13	79.01	82.54	84.24	80.26
3	130	54.03	57.13	63.25	65.42	61.56
4	180	57.15	59.66	62.92	58.89	52.19
5	230	64.86	66.06	68.61	63.22	57.19
6	280	67.01	68.36	71.84	69.52	59.93