Patent ID: 6772105
Filing Date: 2004-08-03
Classification: E21C,F42D,G01V

Abstract:
A method for establishing a drill pattern for a plurality of boreholes of predetermined diameter for use with a specified explosive material along a drill line along a bench of rock having a known density and a rock face, the method comprising:(a) defining a drill line having a start point and an end point; (b) determining a target rock burden BT for a hypothetical borehole having the predetermined diameter at the start point; (c) defining along the drill line a progression of successive layers of rock each defining an incremental burden, determining the cumulative burden Bcum of the defined layers and revising BT with each successive layer until Bcum accounts for one-half BT; and then (d) setting and indicating a position for the borehole on the drill line in the layer most distant from the start point; (e) defining additional successive layers of rock until the total of the incremental burdens of the layers defined in steps (c) and (e) accounts for BT; (f) setting and indicating a location for a distant boundary of the rock burden for the borehole; and (g) using the distant boundary as the start point for an additional borehole and repeating steps (b), (c), (d), (e) and (f) for each additional borehole until a layer coincides with the end point.