Study of Testing Method for Dynamic Initiation Toughness of Sandstone under Blasting Loading

Table 3

Time of the crack fracture.

Specimen number	Strain gauge number	Distance ratio	Strain time parameters (μs)
			Start time	Fracture time	Fracture accumulation time
1	Gauge 2	4	38.0	79.9	41.9
2	Gauge 2	4	37.5	84.4	46.9
3	Gauge 2	4	39.5	86.4	47.0
4	Gauge 2	4	38.7	78.8	40.1
Average		4	38.4	82.4	44.0