Patent ID: 6293355
Filing Date: 2001-09-25
Classification: E21B,E21C,E21D

Abstract:
A method of controlling rock drilling when a plurality of holes are drilled based on a cross section of a tunnel in accordance with a predefined drilling pattern corresponding to a blasting depth of a predetermined length, a position and length of each of the plurality of holes to be drilled being defined in a three-dimensional coordinate system, and a starting point of each of the plurality of holes in a collaring surface, which is crosswise of the tunnel and is different from an actual rock surface, being defined, and a direction and the length of the plurality of holes of the drilling pattern being defined in accordance with an advanced plan so that positions of end points of the plurality of holes in relation to one another are predetermined, and when a drilling depth needed for the blasting differs from said predetermined blasting depth, a drilling length in the drilling pattern is changed by transferring the position of the pattern in a longitudinal direction of the tunnel in accordance with the change in the blasting depth so that the positions of the end points of the plurality of holes in said three-dimensional coordinate system are transferred by said length but remain essentially the same with respect to one another, and that said collaring surface, where the starting points of the plurality of holes are defined, is maintained the same so that the distance between the end points of the plurality of holes and said collaring surface in the longitudinal direction of the tunnel changes by the change in said blasting length.