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 cable bolt for providing support and balance to a rock mass, comprising: a multi-strand cable having a plurality of steel wires being twisted together, said multi-strand cable having a first end portion for anchoring in a borehole of rock mass and a second end portion for being positioned adjacent to the opening of the borehole, a fixture secured to the second end portion of said multi-strand cable, wherein at least one of the plurality of steel wires is made from steel having as steel composition: a carbon content ranging from 0.20 weight percent to 0.95 weight percent, a silicon content ranging from 0.5 weight percent to 2.0 weight percent, a manganese content ranging from 0.40 weight percent to 1.0 weight percent, a chromium content ranging from 0.0 weight percent to 1.0 weight percent, a sulphur and phosphor content being limited to 0.025 weight percent, the remainder being iron and unavoidable impurities, and said steel has as metallurgical structure: a volume percentage of retained austenite ranging from 4 percent to 25 percent, the remainder being tempered primary martensite and untempered secondary martensite.

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.

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.

An inflatable rock bolt including an expansion tube, a bushing arranged at each end of the expansion tube, and at least one reinforcing member arranged outside the expansion tube. The at least one reinforcing member includes at least one of a strand extending along the expansion tube or a sleeve at least partially surrounding the expansion tube. A method for reinforcing an inflatable rock bolt.

A rock bolt includes an elongate metallic body having a first end and an opposed second end, a threaded portion at the second end, for attaching thereto and locating thereon, a nut and a bearing plate, a mechanical anchor at, or at least partially located on, a first end portion of the body and a first resistive anchor, located between the threaded portion and the mechanical anchor.

A rock bolt device that includes a non-anchoring elongation section that allows elongation of the rock bolt device under tensile load to accommodate rock movement after installation of the rock bolt device.

A mine bolt includes an elongated body having a first end and a second end positioned opposite the first end, with the elongated body having a first threaded section, a second threaded section, and a non-threaded section positioned between the first threaded section and the second threaded section. The non-threaded section is configured to yield under loading when the mine bolt is installed with grout in a bore hole.

The invention provides an end anchored rock bolt 20 which includes an elongate cylindrical body 12 which longitudinally extends between a proximal end and a distal end and a plug 18 at the distal end, which plug is diametrically larger than the cylindrical body 12, is at least partially tapered, tapering towards the proximal end, and is integrally formed on the body 12.

The invention relates to a yieldable rock anchor comprising an anchor element extending along a longitudinal center axis and having a first end, a second end and an outer surface. An anchor plate is attached near the first end of the anchor element, and an anchor head is secured to the first end of the anchor element and adapted to clampingly engage the anchor plate. On its outer surface, the anchor element is provided along at least substantially its entire length with a plurality of ribs. A plurality of sleeves, each sleeve having two opposing ends, for covering some of the plurality of ribs is fixedly arranged on the outer surface of the anchor element such that each of the opposing ends at least substantially sealingly engages the outer surface of the anchor element.