The size of the drilling hole (specifically, the hole diameter) is one of the most significant factors affecting the drilling time for a rock drilling machine.
The relationship is not linear; it's exponential. This means that increasing the hole diameter by a small amount can lead to a much larger increase in drilling time.
While smaller holes are drilled faster, the choice of hole size is a critical engineering decision based on the project's overall goal:
Small-Diameter Holes (Blast Holes): Used for quarry blasting. Many small, quickly drilled holes are loaded with explosives to break the rock efficiently.
Large-Diameter Holes: Used for foundational piles (piers), water wells, geothermal wells, and ground anchoring. The need for a large, stable structure outweighs the increased drilling time and cost.
