Patent ID: 8899883

Claim:
A mine roof bolt assembly for securement in a drill hole pre-formed in a rock complex, the bolt assembly including, an elongated tendon extending longitudinally along a tendon axis from a proximal end to a distal end, the tendon being sized for insertion at least partially in said drill hole and including, an externally threaded portion proximate said first end, a substantially non-deformable rigid anchor portion spaced towards said distal end, the rigid anchor portion including a plurality of first anchoring members which are engagable by an anchoring grout to fixedly couple the rigid anchor portion to first laterally adjacent portions of said rock complex under load forces which exceed a predetermined threshold force, a deformable anchor portion remote from said rigid anchor portion, the deformable anchor portion including a plurality of second anchoring members which are engagable by said anchoring grout to at least partially couple the deformable anchor portion to second laterally adjacent portions of said rock complex, the deformable anchor portion configured for limited axial deformation under said load forces to maintain at least partial coupling between the deformable anchor portion and said second laterally adjacent portions of said rock complex, and at least one plastically deformable portion intermediate said rigid anchor portion and said deformable anchor portion, each said plastically deformable portion being deformable axially relative to third, laterally adjacent portions of said rock complex under said load forces, and a thread fastener sized for threaded mated engagement with said externally threaded portion.