A friction stabilizer for supporting a rock ceiling in an underground mining environment is disclosed. The friction stabilizer has an external sheath and an internal rod. The internal rod is about 15% of the length of the external sheath. The internal rod has wedges at either end, arranged to engage with complementary wedges welded to the inside of the sheath.

Disclosed is a rock bolt assembly including: an elongate bolt extending with distal and proximal ends; a tubular sleeve longitudinally extending between leading and trailing ends on the bolt so at least a proximal end portion projects from the trailing end of the sleeve; and a nozzle docking bush on the proximal end portion between the sleeve's trailing end and the bolt's proximal end. The bush has a cylindrical body between first and second ends, a central hole extending through the body, spaced-apart annular ridges on the cylindrical body, a grout distributing channel between the ridges, and an aperture in the channel connecting the channel and hole. The central hole includes a leading portion ending at the first end, sealingly receiving the trailing end. A trailing portion of the central hole ends at the second end and sealingly engages the bolt. Each annular ridge seals against a grout nozzle.

An end coupling for a rock bolt having a shaft having an external thread, the coupling having an axis and the coupling comprising a body having a leading end and a trailing end spaced apart along the axis, a first passage portion extending along the axis from the leading end; a second passage portion extending along the axis from the trailing end; the first passage portion including a first thread portion to threadingly engage the external thread on the shaft of the rock bolt; the second passage portion including a drive receiving portion arranged to be engaged with a drive inserted into the second passage portion via the trailing end to impart rotation to the coupling about the axis.

A constant-resistance and large deformation anchor cable and a constant-resistance device are provided. The constant-resistance and large deformation anchor cable comprises cables (7), an anchoring device (13), a loading plate (12) and clipping sheets (4). The upper end of cables (7) is fixed on the anchoring device (13) and the loading plate (12) by clipping sheets (4). The constant-resistance and large deformation anchor cable also comprises a constant-resistance device, and the constant-resistance device comprises a sleeve (8) and a constant-resistance body (5). The sleeve (8) is a straight tube. The constant-resistance body is conical, and the diameter of the lower end of the constant-resistance body is bigger than the diameter of the upper end of the constant-resistance body. The inner diameter of the sleeve (8) is smaller than the diameter of the lower end of the constant-resistance body. A cuneiform part is arranged on inner wall of the lower end of the sleeve (8), and the constant-resistance body (5) is arranged on the cuneiform part. The strength of constant-resistance body (5) is higher than the strength of the sleeve (8), thus the sleeve (8) generates plastic deforming and the shape of the constant-resistance body (5) is not changed, when the constant-resistance body (5) moves in the sleeve (8). The lower end of the cables (7) is fixed on the constant-resistance body (5). The constant-resistance and large deformation anchor cable and the constant-resistance device have the properties of constant-resistance and preventing fracture, and can detect and early warn the all process of the activity of the landslides and the causative fault.

A rock bolt to be embedded in a borehole and a method of manufacturing a rock bolt, the rock bolt including an extended energy-absorbing part, the first end of the energy-absorbing part including an anchor and the second end of the energy-absorbing part including a screw joint for prestressing the rock bolt. The rock bolt includes an extended tubular part with a jacket and a first end section and a second end section, with an internal dimension that is larger than the external dimension of the energy-absorbing part and arranged in such a manner that it surrounds the energy-absorbing part.

The present invention relates to a device, method and system for the installation of a fixative in a drill-hole, such as to secure rock bolts. The device comprises (a) a chamber adapted to hold the fixative, and (b) a thrust member, wherein the fixative is displaced from the chamber into the drill-hole following application of force to the thrust member.

An encapsulation system for use in securing a rock bolt in a bore hole drilled into a rock face to be stabilised, the encapsulation system comprising at least two separate encapsulation mediums and one or more elongate cartridges containing the encapsulation mediums, each the cartridge having a frangible casing, the encapsulation mediums including: a first encapsulation medium comprising a curable first resin formulation; and a second encapsulation medium; wherein, following use in securing a rock bolt, the second encapsulation medium has a lower bond strength and/or a lower compressive strength than the first resin formulation.

The present invention discloses a self-anchored opposite-pulling anti-impact anchor cable for sectional coal pillars and a using method thereof. The anchor cable includes a steel strand (100), with an energy-absorbing and yielding terminal (200) and a stressed expansion-cracking terminal (300) respectively fixed to two ends of the steel strand, a bushing (400) sleeved outside the steel strand, a first lock (610) provided at one end of the steel strand and a second lock (620) provided at the other end of the steel strand; the stressed expansion-cracking terminal includes a self-anchored bushing (420) with a plurality of pre-splitting lines (440) arranged in the wall of the self-anchored bushing. Under stress, the wall of the self-anchored bushing cracks along the pre-splitting lines and bends and expands, so that it abuts against and is self-anchored to the edge of a sectional coal pillar at the outer side.

Disclosed is a rock bolt assembly including: an elongate bolt extending with distal and proximal ends; a tubular sleeve longitudinally extending between leading and trailing ends on the bolt so at least a proximal end portion projects from the trailing end of the sleeve; and a nozzle docking bush on the proximal end portion between the sleeve's trailing end and the bolt's proximal end. The bush has a cylindrical body between first and second ends, a central hole extending through the body, spaced-apart annular ridges on the cylindrical body, a grout distributing channel between the ridges, and an aperture in the channel connecting the channel and hole. The central hole includes a leading portion ending at the first end, sealingly receiving the trailing end. A trailing portion of the central hole ends at the second end and sealingly engages the bolt. Each annular ridge seals against a grout nozzle.

A method is defined for attaching mounted parts on a mounting substrate formed of concrete or masonry, having a group of anchors wherein the following is true for the ratio VSd/NSd of the rated value for the transverse load VSd and of the rated value of the tensile load NSd of at least one anchor in the anchor group: VSd/NSd≥0.3, preferably VSd/NSd≥0.6 and particularly preferably VSd/NSd≥1.0, and wherein the characteristic resistances of these anchors to transverse loading VRk or to tensile loading NRk satisfy the following relationship: VRk/NRk≤1.1. The at least one anchor of the anchor group is inclined at an angle αAnker to the perpendicular to the surface of the mounting substrate in such a manner that the following is true: αAnker=k*¾*arc tan (VSd/NSd) for NSd>0, and αAnker=k*67.5° for NSd=0, where: 0.8≤k≤1.34, providing that αAnker≤75°.