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The objective of the investigation was to determine if a significant increase in the strength of the model pillar could be obtained by either (1) installing tensioned rock bolts through the pillar and normal to the plane of weakness, or (2) wrapping tensioned steel wire ropes around the pillar at uniform spaced intervals along the pillar. The effect of installing tensioned rock bolts normal to the plane of weakness of the model pillar is shown to be equivalent to increasing the shear resistance along the plane of weakness. The strength increase depends upon the shear strength of the rock bolt, the tensile stress in the rock bolt, the ratio of the cross-sectional area of the bolt to the area of the weakness plane, and the number of bolts installed. The effect of wire roping a model pillar is shown to be analagous to applying an effective confining pressure over the specimen surface. The value of the effective confining pressure is dependent upon the tensile force in each wire and the total number of wires. These results are substantiated by a finite element study of the wire roping problem. Equations, based on Coulomb's failure criterion, are developed to predict unixial compressive strength of model pillars that are either rock bolted or wire roped. (Author)