ABSTRACT
Ground Support in Mining and Underground Construction-Villaescusa & Potvin (eds.) © 2004 Taylor & Francis Group, London, ISBN 90 5809 640 8
ABSTRACT: Big Bell introduced cone bolts in 1999 as one of many ground reinforcement options investigated to manage the damage resulting from rockbursts. The timing and location of installation of the cone bolts changed with mine requirements from 1999 to 2002. Initially the bolts were installed in the footwall amphibolite access development, before the development was exposed to stoping stress change. Following their success in maintaining rockbursts the bolts were installed in oredrive schist. The bolt was then exposed to the higher deformation ground response from the schists. The bolts were then exposed to the complete deformation history of the drive when installed with the development cycle. The paper will discuss the factors for cone bolt breakage, the required modification to installation practices, and improvements introduced to maintain the entire support system performance.
