Numerical Evaluation on Dynamic Response of Existing Underlying Tunnel Induced by Blasting Excavation of a Subway Tunnel

Table 2

Safety vibration limitation for tunnels and shafts in China [32].

Structure type	Allowable safety peak particle velocity/cm/s
	≤ 10 Hz	10 Hz ≤ ≤ 50 Hz	> 50 Hz
Hydraulic tunnels	7~8	8~10	10~15
Traffic tunnels	10~12	12~15	15~20
Mining shafts	15~18	18~25	20~30