The present invention pertains to a yieldable rock anchor (10), comprising an elongated tendon (12) extending longitudinally along a tendon axis (A) from a proximal end (16) to a distal end (18), wherein the tendon includes a substantially non-yielding rigid first anchor portion (20) at or near said distal end (18) and extending towards said proximal end (16), and at least one plastically deformable axially yielding portion (26) intermediate said non-yielding rigid first anchor portion (20) and said proximal end (16). The first anchor portion (20) may be a hollow bar member, and the first anchor portion (20) and the at least one yielding portion (26) are integrally joined or coupled to one another to form at least part of said elongated tendon (12).

A rock bolt assembly provides an indication of a coupling. The rock bolt assembly includes two shaft sections, namely inner and outer shaft sections. A coupler is configured to couple the two shaft sections together at proximate ends. An electrical conductor is insulated from the outer shaft section and extends from the dead end of the outer shaft section to the head at the live end of the outer shaft section. An electrical contact arrangement is provided at the dead end of the outer shaft section, configured to electrically interconnect the outer shaft section and the conductor when the inner and outer shaft sections are coupled. Electrical terminals are provided at the head and connected respectively to the outer shaft section and to the conductor, the electrical terminals being electrically interconnected or continuous when the outer shaft section and the conductor are electrically interconnected.

A rock anchor assembly includes a rock anchor with a flexible element and first/second cylindrical connector elements engaged to proximal and distal ends of the element, a flexible tubular sleeve longitudinally extending between first and second ends, on the rock anchor so end parts of the rock anchor project from sleeve ends; a load bearing barrel centrally bored engaging the first connector element between the first end of the sleeve and a proximal end of the rock anchor, the barrel engaging the first end of the sleeve in sealing contact, the barrel having a grout conduit between the barrel exterior and the bore, the conduit defining part of a grout passage interconnecting the barrel exterior and sleeve interior, when the barrel engages the sleeve; a seal preventing grout outflow but accommodating grout inflow; a tensioner engaging the first tubular connector element, and a mechanical anchor engaging the second tubular connector.

A system for re-tensioning mine roof channels includes a roof plate having a first side, a second side positioned opposite the first side, and a sidewall extending therebetween, where the first side is configured to engage a surface of a mine roof, and where the sidewall defines a radially extending slot configured to receive a mine roof bolt. The system also includes a spacer having a first side, a second side positioned opposite the first side, and a sidewall extending therebetween, with the first side of the spacer configured to engage with the second side of the roof plate, and the sidewall defining a slot configured to receive a mine roof bolt, and a nut having a first side, a second side positioned opposite the first side, a sidewall therebetween, and a threaded opening, with the sidewall defining a radially extending slot configured to receive a mine roof bolt.

A friction bolt assembly includes: an expansible sleeve having a tubular body between leading and trailing ends, which body has a longitudinally extending formation about which the body resiliently deforms and which formation extends along at least part of the body, ending at the body leading end; a rod extending through the sleeve body and between first and second ends and on which a projecting part is defined between the trailing end of the sleeve body and the second end; an expansion element on the rod at the first end; a first load bearing formation on the projecting rod part, moveable along the projecting part to abut the sleeve trailing end; a load applicator on the projecting part of the rod; and a second load bearing formation mounted over the projecting part of the rod between the first load bearing formation and the load applicator unit.

A rock bolt assembly includes a rock bolt with an elongate body between distal and proximal ends, a tubular sleeve with first and second ends, proximal and distal ends of the bolt projecting from first and second ends of the sleeve, a load bearing barrel centrally bored to engage the rock bolt between the sleeve's first end and the bolt's proximal end, which barrel is adapted at a forward end to engage with the sleeve's second end in sealing contact, and which barrel has at least one grout conduit between the barrel's exterior surface and the bore, which at least one conduit defines a part of a grout passage which communicates the exterior surface of the barrel with an interior of the sleeve, when the barrel is engaged with the sleeve, and a seal which seals the grout passage to grout outflow but accommodates inflow of grout from a source.

The present application relates to a system for supporting a roof of a portion of a mine. The system includes a first plurality of stabilizing members disposed above the roof at a first elevation. The first plurality of stabilizing members originate from a first common location and terminate at a second elevation that is higher than the first elevation. The system further includes a second plurality of stabilizing members disposed above the roof and the first plurality of stabilizing members at a third elevation. The second plurality of stabilizing members originate from a second common location and terminate at a fourth elevation that is higher than the third elevation. The second plurality of stabilizing members are disposed generally perpendicular to the first plurality of stabilizing members.

A rock anchor assembly includes a rock anchor with a flexible element and first/second cylindrical connector elements engaged to proximal and distal ends of the element, a flexible tubular sleeve longitudinally extending between first and second ends, on the rock anchor so end parts of the rock anchor project from sleeve ends; a load bearing barrel centrally bored engaging the first connector element between the first end of the sleeve and a proximal end of the rock anchor, the barrel engaging the first end of the sleeve in sealing contact, the barrel having a grout conduit between the barrel exterior and the bore, the conduit defining part of a grout passage interconnecting the barrel exterior and sleeve interior, when the barrel engages the sleeve; a seal preventing grout outflow but accommodating grout inflow; a tensioner engaging the first tubular connector element, and a mechanical anchor engaging the second tubular connector.

The present application relates to a system for supporting a roof of a portion of a mine. The system includes a first plurality of stabilizing members disposed above the roof at a first elevation. The first plurality of stabilizing members originate from a first common location and terminate at a second elevation that is higher than the first elevation. The system further includes a second plurality of stabilizing members disposed above the roof and the first plurality of stabilizing members at a third elevation. The second plurality of stabilizing members originate from a second common location and terminate at a fourth elevation that is higher than the third elevation. The second plurality of stabilizing members are disposed generally perpendicular to the first plurality of stabilizing members.

This invention puts forward a sectional modular large-deformation-resistant impact-resistant composite rock bolt and its assembling method. The outer anchor module of this composite rock bolt consists of the outer anchor end, anchor tubes and anchor piers, all of which are bonded with the borehole wall through the anchorage agent to act as a full-grouted bolt. And the inner anchor module consists of the outer anchor end, anchor piers, springs and threaded rod. The threaded rod, under the traction by the outer anchor end, presses the inner anchor springs to distribute the anchoring force to the anchor piers, which then pass such force as a pressure to the anchoring agent, thus playing the role of a pressure-dispersive anchor. Before the failure of the anchor tube, the inner anchor module is in parallel with the outer anchor module, playing the role of auxiliary anchorage on surrounding rock; after the failure of the anchor tube, such structure can yield and buffer effectively against the surrounding rock and realize secondary high-strength support timely.