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.

A rock bolt includes a wedge-based expansion mechanism. The expansion mechanism includes a drive wedge arranged to expand an intermediate wedge upon tensioning of the rock bolt, wherein the intermediate wedge is arranged to expand a wedge device attached to an outer tube of the rock bolt. The use of the intermediate wedge enables greater expansion of the rock bolt.

A friction bolt assembly to frictionally engage a bore formed in rock strata includes an elongate tube and an expander mechanism acted on by an anchor mechanism via an elongate bar or cable. A retainer mechanism is mounted to act between the bar or cable and the tube to prevent ejection of the bar or cable from the assembly should the bar or cable break.

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.

A multi-stage pressure yielding and anti-impact device for anchoring support is proposed, which includes an anti-impact component, a secondary pressure yielding component, and a primary pressure yielding component. The primary pressure yielding component and the secondary pressure yielding component each include an outer sleeve, an inner extrusion sleeve, and an expansion platform, and the expansion platform is arranged at a bottom end of the inner extrusion sleeve. A buffering and energy-absorbing material filling body is arranged between the outer sleeve and the inner extrusion sleeve. An outside diameter of the outer sleeve in the primary pressure yielding component is equal to that of a large-diameter end of the expansion platform in the secondary pressure yielding component, and the outer sleeve in the primary pressure yielding component is pressed against a bottom of the expansion platform in the secondary pressure yielding component.

A friction bolt assembly has a tubular friction bolt body defining a cavity and having a split. A rod extends through the cavity. An expansion element is mounted on the rod at or toward the rod leading end and protrudes through the friction bolt body leading end. The expansion element has an engagement surface tapering toward the rod trailing end. A drive head is mounted on the rod at or adjacent the rod trailing end. The rod is actuatable by rotation of the drive head to draw the expansion element toward the friction bolt body trailing end such that the engagement surface engages the friction bolt body, radially outwardly deforming the friction bolt body.

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.

An anchoring device and method of securing an anchoring device to strata are disclosed. The anchoring device (1) includes a drilling rod (2) and an anchoring sleeve (3) at least partially surrounding the drilling rod (2), the drilling rod (2) comprising a driving end (31) for coupling to a drilling apparatus and a drilling end (32) with a drilling head (26) for drilling a hole in strata, wherein the device is configured to be coupled with and driven by a drilling apparatus to cause the drilling head (26) to drill a hole into strata and to force, as the hole is drilled, the anchoring sleeve (3) into the hole to an inserted position in which the anchoring sleeve (3) engages the surrounding strata.

A bearing plate and a nut and bolt arrangement for use as a rib or roof support for coal mines where the extracted coal is used for powder coal and has a specific gravity in the range of 1.5-1.9, preferably 1.7. The bearing plate has an outer reinforced area surrounding an inner reinforced area. The outer reinforced area has one or more endless rib members and the inner reinforced area has a plurality of legs, wherein the legs are spaced from one another and the first end of each leg encircles a bolthole in a center of the bearing plate to receive the bolt of the nut and bolt assembly. The bearing plate and the nut and bolt assembly are made of fiberglass reinforced plastic.