A friction bolt assembly, such as for use with a pneumatically actuated drill, with a friction fit tubular sleeve longitudinally extending between a leading end and a trailing end, a rod which longitudinally extends through the sleeve between a first end and a second end, and which projects from either end of the sleeve to define, between the first end of the rod and the leading end of the sleeve and the second end of the rod and the trailing end of the sleeve respectively, a leading part and a trailing part, an expansion element mounted on or formed with the rod, on the leading part, a drill engaging element axially fixed in position on the second end of the bolt and engageable with a chuck or an end of the rock drill, a first load bearing formation mounted on the trailing part of the rod and which engages the trailing end of the sleeve, and a second load bearing formation mounted over the trailing part of the rod between the first load bearing formation and the drill engaging element.

A bung has a body which extends between a leading end and a trailing end and which includes an inner part of a rigid material which has a cylindrical aperture for receiving a rock bolt and an outer sealing part of a resiliently deformable material circumscribing the inner part. The inner part and the outer part engage at an interface which has a co-efficient of friction which allows the outer part to disengage from the inner part at the interface when a shear force above a predetermined level is applied to the outer part or the inner part.

Rock anchors, inflation chucks, and inflation systems such as those described herein, allow for substantially complete draining of fluids from interior volumes of the rock anchors. In various situations, corrosive fluids may be introduced to the rock anchor, including inflating the rock anchors and during normal use, such as by groundwater intrusion. The inflation chucks described herein include multiple inflation paths for more effectively introducing and draining fluid from rock anchors during inflation processes and during general use.

Rock anchors, inflation chucks, and inflation systems such as those described herein, allow for substantially complete draining of fluids from interior volumes of the rock anchors. In various situations, corrosive fluids may be introduced to the rock anchor, including inflating the rock anchors and during normal use, such as by groundwater intrusion. The inflation chucks described herein include multiple inflation paths for more effectively introducing and draining fluid from rock anchors during inflation processes and during general use.

Disclosed is a grout anchored rock bolt which includes an elongate cylindrical body of a suitable material which has at least one integral anchor portion which includes of a plurality projection, each of which extends laterally from the body in at least one radial direction, wherein the projections are consecutively serially arranged along the length of the anchor portion and wherein each projection is radially offset relatively to the preceding formation at an angle that is not orthogonal.

The invention is an application that completely alter the operating principle and load transfer mechanism of the anchorage technique used in the field of civil engineering, in particular at the excavation bracing and slope stability applications with a novel root zone apparatus.

The invention discloses a retrievable sand consolidation anchor head prestressed anchor rod, an anchoring jack and an application method thereof, and belongs to the technical field of geotechnical engineering. The retrievable sand-consolidated anchor head pre-stressed anchor includes a bolt body 6, a rigid frame 5, a load member 1, a sand column 2, a pressure receiving member 4, a cut-off member 3, and an anchor pier 8. The anchoring jack includes a force transmitting frame 12, a first guiding plate 25, a second guiding plate 28, and a housing 13. The application method includes an anchoring method using the retrievable sand-consolidated anchor head prestressed anchor rod and a method of recovering the retrievable sand-consolidated anchor head pre-stressed anchor rod. After the anchoring of the reclaimed sand-consolidated anchor head pre-stressed anchor rod, the bolt body can be recovered and reused, and the operation is simpler and more environmentally friendly.

An energy-absorbing rockbolt includes an anchorage structure, wherein two ends of the anchorage structure are respectively provided with a mixing blade and a threaded fastening section; a nut is screwed to the threaded fastening section; a plate is mounted at one end, which is close to the threaded fastening section, of the anchorage structure in a sleeving manner; one side of the plate abuts against the nut; the anchorage structure consists of first anchorage structure parts and second anchorage structure parts, wherein the second anchorage structure parts are arranged between two first anchorage structure parts; each of the second anchorage structure parts is an elliptical rod-shaped structure; a plurality of inwardly-concave arc-shaped grooves are formed in an outer wall of the second anchorage structure part in an axial direction, and a reinforcing rib is convexly formed at an intersection of two adjacent arc-shaped grooves.

Disclosed is a centralising positioner for a resin bolt which includes a central attachment part which is adapted to engage a leading end of the bolt and a positioning part integral with the attachment part that extends from the attachment part.

Disclosed is a resin bolt which includes an elongate shaft which extends between a leading end and a trailing end and a positioning head which is integral to the shaft at the leading end and which extends in the elongate axis of the shaft from a perimeter rim to a crown, with the head formed with a plurality of projections, with each projection extending laterally, beyond the radial dimension of the shaft and each projection having a leading surface which slopes, at least partially, from the crown to the perimeter rim, and a trailing surface from the perimeter rim to the shaft.