Abstract: A rock anchor assembly comprising a metallic tubular element adapted to be inserted into a bore hole so that one end portion thereof extends a distance from the closed end of the bore hole and the other end portion thereof extends from the opening of said bore hole, said other end portion thereof containing a threaded section for receiving a clamp nut, an anchor plate having a size larger than the bore hole and disposed against the face of said bore hole between the clamp nut and said face, at least one reinforcing element disposed in said tubular element, filling means for introducing the synthetic resin into the bore hole, said synthetic resin holding a reinforcing element in position within said tubular element, and at least one sealing ring disposed around the external surface of the tubular element adjacent said threaded section for sealing the bore hole wall when the head of the rock anchor is introduced into the bore hole.