A new perspective on cable bolt design

CIM Bulletin, Vol. 85, No. 962, 1992

P.K. Kaiser, S. Maloney and S. Yazici, Geomechanics Research Centre, Laurentian University, Sudbury, Ontario,

This paper focusses on the strength or capacity of cable bolts and introduces a new perspective for cable bolt design by demonstrating that mining-induced stress changes may affect cables in a detrimental manner. The concept underlying a novel cable bolt pull-out resistance or bond capacity model is described and its practical significance is demonstrated by application to a simple two-dimensional scenario of a fall-of-ground. A number of practical implications emerging from the application of this model are discussed to provide guidance to ground control personnel for improving cable bolt support systems in mining applications. These include cable layout optimization, use of cable pre-reinforcements, assessment of embedment length requirements, need for plated cables (or straps), use of bird-caged cables (or buttons), and grout quality issues.