the drill hole application_number US 91843001 A description referring to fig1 there is shown a rock stabilizing apparatus for anchoring unstable rock formations 12 to stable rock formations 14 in mining operations of a preferred embodiment of the invention generally designated as 10 the apparatus is shown in its pre torque max and pre torque shear states the apparatus is adapted to be inserted into a pre drilled hole 16 that extends through the unstable portion 12 to a stable portion 14 of the rock formation as might be found in the roof or wall of a mine tunnel the apparatus comprises a tensionable member 18 in a preferred embodiment of the invention the member is a reinforcing member generally tubular in shape having a top ribbed portion 100 and a bottom threaded portion 101 in alternative embodiments of the invention the reinforcing member may comprise one of a steel bar a cone bolt a standard rock bolt or a reinforcing cable the portion inserted into the drilled hole may be smooth or textured to promote adhesion to the adhesion material as shown in fig1 the diameter of the member 18 is less than the diameter of the drilled hole 16 this forms an annulus 103 around the member 18 the annulus is filled with a suitable hardenable adhesion material 102.