Study on the propagation mechanism of blast waves using the ultra-dynamic strain test system

The propagation mechanism of blast waves in rock materials is hard to test. This paper explores the propagation mechanism of blast-induced strain waves in coal and rock using physical modeling together with numerical modeling. The results show that the strain waves in coal blocks were weaker than that in mortar blocks under the same blast loading. With increasing distance, the strain waves induced by the shock wave show a slighter decrease in coal blocks in the radial direction, but show a stable tendency in coal blocks and a slight decrease in mortar blocks in the tangential direction. However, the strain waves induced by the explosion gas show a stable tendency in both coal and mortar blocks. The actuation duration of strain waves in coal blocks is longer than that in mortar blocks. The gap of the radial strain waves induced by shock waves is narrowed gradually and moved similarly equal to each other both in coal and mortar blocks with increasing distance. The simulated results show similar values in coal and mortar blocks as compared with the test results. The coal blocks have a better fracturing effect than that of the mortar blocks in the physical test.