Working Safely Under Inverse Raise Boreholes at Brunswick Mine The story of The 'Trampoline'

摘要

Inverse raise boreholes, 0.762m (30") diameter and up to 22m long are used at Xstrata Zinc Canada's Brunswick Mine as inverse slot raises to make room for production upper blast holes. Working under these big and long open boreholes (for production drilling and blast loading) cannot be allowed unless a tough back mounted rock fall protective device is installed. This paper describes a compact device that was developed at Brunswick Mine and dubbed the "trampoline". It is constructed of a heavy gage chain link mesh reinforced by air craft steel cables interlaced. Two steel plates with a "comb" like shape hold the net and help to affix it to the back with conventional ground support hardware.