A friction bolt assembly to frictionally engage a bore formed in rock strata. The assembly 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.

The present disclosure relates to a construction method for a deformable anchor cable capable of being prestressed. The anchor cable includes an outer sleeve, a shrinkage pipe, an inner sleeve, a steel strand, an anchor and a tray. When the anchor cable is in use, a hole is drilled first, then the anchor cable is mounted in the drilled hole, and finally a prestress is applied to the steel strand of the anchor cable. According to the construction method, the construction is convenient; the anchor cable has the characteristics of high strength and large deformation, and can be easily prestressed; and the large deformation is realized by squeezing the inner sleeve by means of the anchor, which completely overcomes the problem of breaking a cold-drawn rod during the large deformation process.

A cable bolt assembly is disclosed comprising a cable bolt having a shaft, an end fitting disposed on the shaft and including an end fitting body. Mechanical interlocking is provided between the body and the shaft to form a connection therebetween. The mechanical interlocking may be formed directly between the body and the shaft and/or by engagement formations disposed intermediate the body and shaft. The body further including an exterior profiling arranged to engage a further component of the end fitting to install and/or tension the cable bolt assembly in use. A method of forming the cable bolt assembly is also disclosed.

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 encapsulation system (100) for use in securing a rock bolt in a bore hole drilled into a rock face to be stabilised, said encapsulation system comprising at least two separate encapsulation mediums (112,122) and one or more elongate cartridges (110,120) containing said encapsulation mediums (112,122), each said cartridge having a frangible casing (111,121), said encapsulation mediums including: a first encapsulation medium (112) comprising a curable first resin formulation; and a second encapsulation medium (122); wherein, following use in securing a rock bolt, said second encapsulation medium has a lower bond strength and/or a lower compressive strength than said first resin formulation.

A rock bolt (10) to be received in a drilled hole comprising a threaded shaft (12) and a sleeve (14) into which the shaft (12) is received. A plurality of openings (38) are provided along the length of the sleeve (14) and clamping assemblies (16) each having clamp members (36) are provided adjacent each opening (38). Wedge members (26) are located adjacent each of the clamp members (36) and the wedge members (26) each include a threaded bore for receiving the shaft (12) such that rotation of the shaft (12) moves the wedge members (26) into engagement with the clamp members (36) to move the clamp members (36) outwardly through the openings (38) to engage with an inner surface of the hole.

A rock bolt (10) is provided for frictionally engaging with the internal surface of a bore drilled into rockmass. The bolt comprises a tube having a circular cross-section (12) defining a longitudinal split (14) and a longitudinal axis (10a). The tube (12) in is radially expandable. The bolt (10) has a first leading end (12b) for insertion into a bore, a second end defining a head (12a) and expander means (30) for expanding the diameter of the tube at least one location along the tube. The expander means comprises first (42) and second (44) expander/wedge elements arranged so that relative movement of the two elements causes the diameter of the tube to expand at that location. The first expander element (42) is mounted on an elongate rod (30) which is aligned generally along the longitudinal axis of the tube. Rotation of the rod (30) causes the relative movement of the two elements to cause the diameter of the tube to expand at the location. The rock bolt includes an arrestor (100) in the form of a ring, which defines an aperture which locates on the proximal end of the rod (30). The aperture is larger than the proximal end of the rod so that the arrestor is able to move along the proximal end of the rod. The arrestor includes a laterally extending protrusion (102) which locates in the longitudinal split (14) and is narrower than the longitudinal split and which is configured to engage with the head of the friction bolt when moved towards the proximal end of the friction bolt.

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/NSd0.3, preferably VSd/NSd0.6 and particularly preferably VSd/NSd1.0, and wherein the characteristic resistances of these anchors to transverse loading VRk or to tensile loading NRk satisfy the following relationship: VRk/NRk1.1. The at least one anchor of the anchor group is inclined at an angle Anker to the perpendicular to the surface of the mounting substrate in such a manner that the following is true: Anker=k**arc tan (VSd/NSd) for NSd>0, and Anker=k*67.5 for NSd=0, where: 0.8k1.34, providing that Anker75.

The invention relates to a system for joining two components or for reinforcing a component, comprising a first and a second threaded sleeve which each comprise the following: an outer thread, with the aid of which the threaded sleeve can be screwed into the respective component and which is suitable to form a composite with the respective component, and a power drive, by which a torque for screwing the threaded sleeve into the respective component can be transmitted to the threaded sleeve. The system further comprises an elongate clamping element which is suitable to be guided through the second threaded sleeve and introduced into or guided through the first threaded sleeve, and which is suitable to axially clamp the first and the second threaded sleeve in such a manner that the first and the second threaded sleeve form opposed composite stresses in the respective component.

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.