Blast Pattern

The geometric arrangement of blast holes across a mining bench, defining the spatial relationship between hole positions in terms of spacing (between holes in a row) and burden (distance between rows and the free face). Blast pattern design is fundamental to achieving target fragmentation, controlling blast direction and energy distribution, and preventing fly rock. Patterns may be square, rectangular, staggered, or echelon. In open pit iron ore and gold mines, blast patterns are designed using specialist software and calibrated against fragmentation outcomes.