Experimental Study on the Influence of Delay Time on Rock Fragmentation in Bench Blasting

Delay time is an important factor in the quality of bench blasting. The development and application electronic detonators make it possible to control timing detonation by a highly precise delay time. It easily achievable way seek better blast fragmentation controlling In order investigate influence on rock fragmentation, eight experiments blasting models with double holes were carried out. average weight 4.59 g pentaerythritol tetranitrate (PETN) was charged into each hole diameter 10 mm. times between set as: 13.69, 27.36, 54.72, 60, 90, 120, 180, 339.6 µs. During loading, breakage processes specimens captured detail high-speed cameras. Full-field strains slope analyzed three-dimensional digital image correlation (3D-DIC) technique. After experiment, coarse fragments backfilled post-blast specimen observe record slope’s final pattern. experimental results showed that transformed from horizontal crack dominance vertical as increased. addition, collected sieved, including fine materials. premise approximate excavation, optimum 180 Compared short such 27.36 µs, x50 improved approximately 25% at significant difference great improvement when range no-shock-wave interaction compared interactions. When determining multi-hole blasting, except for stress wave interaction, factors propagation should also be considered. could contribute references relevant research.