Improved shaft sinking method.

摘要

A method of sinking shafts comprising excavating a series of lifts wherein each lift is excavated by drilling a pattern of blast holes for the full depth of the lift including boring a large diameter hole and creating a chamber at the lower end of the large diameter hole, blasting the walls of the chamber to deposit rock material into the chamber, extracting at least a portion of the rock material created by the blast and repeating the blasting and extraction step throughout the length of the lift wherein on the volume of said lift being blasted the remaining rock broken material is extracted.