Safety Threshold Determination for Blasting Vibration of the Lining in Existing Tunnels under Adjacent Tunnel Blasting

Table 1

Safety vibration limitation for tunnels and shafts in China.

Structure type	Allowable safety peak particle velocity (cm/s)
	f ≤ 10 Hz	10 Hz ≤ f ≤ 50 Hz	f > 50 Hz
Hydraulic tunnels	7∼8	39.0	3
Traffic tunnels	10∼12	37.0	2
Mining shafts	15∼18	31.5	1.5