Safety Distance of Shotcrete Subjected to Blasting Vibration in Large-Span High-Speed Railway Tunnels

Table 5

Safety standard of blasting vibration for mass fresh concrete suggested in Chinese Safety Standard for Blasting Vibration (unit: cm/s).

Fresh concrete of C20		Safety standard of blasting vibration velocity (cm/s)
Predominate frequency f (Hz)		≤10	10–50	>50
Concrete age	0∼3 d	1.5∼2	2∼2.5	2.5∼3
	3∼7 d	3∼4	4∼5	5∼7
	7∼28 d	7∼8	8∼10	10∼12