Quick consideration for rock dowels in block theory and equilibrium analyses

This paper provides the stabilizing forces applied by rock dowels to rock blocks. These rock reinforcing elements are also known as Continuously Mechanically Coupled (CMC) rockbolts, fully grouted bolts, fully grouted rockbolts, fully-bonded rock bolts, passive anchors, passive bolts, and untensioned grouted rock bolts. The formulation is presented within Block Theory and 2-D Limit Equilibrium Analyses. The formulation takes into account the fracture dilatancy that activates a beneficial normal compressive force across the fracture intersected by the dowel, but it does not take into account the dowel-grout-rock interaction. The designer is not forced to guess parameters that, at the design stage, are simply unknown and that no one will ever test in the field. Accounting for dowel-grout-rock interaction increases the design strength of the dowel: however, a small void o defect in the grout may significantly reduce the strength and stiffness assumed in the design, and the design would be unconservative. Only the steel yield stress and the bar diameter are needed: these parameters are specified by the designer in the contract documents.