Explosion energy transmission under side initiation and its effect on rock fragmentation

• Provide insight into the characteristics of the explosion energy transmission process of continuous side-initiation blasting.
• Energy partition of shock and gas components under different initiation methods are investigated with a theoretical analysis.
• Comparison tests between end and side initiation methods are conducted in a hard-rock quarry.
• The selection principle of initiation methods for rocks of different intensities are put forward.

Side initiation is a common initiation method in rock blasting. Reasonable initiation methods have an important influence on rock fragmentation. In this study, the explosion energy-transmission process under the side-initiation method is analyzed. The rock-fragmentation result of side initiation and end initiation are compared with transition material blasting excavation field tests in the Changhe Dam. The results from this theoretical analysis and the field tests show significant differences in the partition of shock and gas energy between different initiation methods. In view of energy transmission, compared with end initiation, shock energy can be converted to gas energy, which results in a reduction in shock energy and an increase in gas energy. In addition, the side-initiation method is suitable for blasting in soft and fissured rocks and for contour blasting. It is unwise to use side initiation in the blasting of hard and compact rocks because it will reduce the proportion of shock energy.